2121 lines
91 KiB
Plaintext
2121 lines
91 KiB
Plaintext
The following is part 1 of a nice intro to CD technology written
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by Andy Poggio in 1988. It appears here in its original form.
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CD Summary Introduction
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As requested by many people, I will post this CD Summary over the next
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several days in five parts of which this is the first. I received
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requests from rec.audio, comp.ivideodisc, and comp.graphics -- so I will
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post it to all these groups. I'm not sure that it is appropriate for
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comp.graphics but I DID receive multiple requests to post it there.
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The summary is somewhat technical but more important it is factual: I
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wrote it after reading the original CD standards documents available from
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Sony or Philips to CD licensees. If you are interested in the standards
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documents, you need to contact them directly -- sorry, I don't have a
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specific contact or phone number.
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I do work for Apple but this summary contains a minimum of Apple
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references. I hope everyone agrees that the result is in keeping with net
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policy on the matter.
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--andy
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CD Summary Part 1
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CD-ROM Technical Summary
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>From Plastic Pits to "Fantasia"
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Andy Poggio
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March, 1988
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Abstract
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This summary describes how information is encoded on Compact Disc (CD)
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beginning with the physical pits and going up through higher levels of
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data encoding to the structured multimedia information that is possible
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with programs like HyperCard. This discussion is much broader than any
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single standards document, e.g. the CD-Audio Red Book, while omitting much
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of the detail needed only by drive manufacturers.
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Salient Characteristics
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1. High information density -- With the density achievable using optical
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encoding, the CD can contain some 540 megabytes of data on a disc less
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than five inches in diameter.
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2. Low unit cost -- Because CDs are manufactured by a well-developed
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process similar to that used to stamp out LP records, unit cost in large
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quantities is less than two dollars.
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3. Read only medium -- CD-ROM is read only; it cannot be written on or
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erased. It is an electronic publishing, distribution, and access medium;
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it cannot replace magnetic disks.
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4. Modest random access performance -- Due to optical read head mass and
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data encoding methods, random access ("seek time") performance of CD is
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better than floppies but not as good as magnetic hard disks.
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5. Robust, removable medium -- The CD itself is comprised mostly of, and
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completely coated by, durable plastic. This fact and the data encoding
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method allow the CD to be resistant to scratches and other handling
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damage. Media lifetime is expected to be long, well beyond that of
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magnetic media such as tape. In addition, the optical servo scanning
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mechanism allows CDs to be removed from their drives.
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6. Multimedia storage -- Because all CD data is stored digitally, it is
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inherently multimedia in that it can store text, images, graphics, sound,
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and any other information expressed in digital form. Its only limit in
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this area is the rate at which data can be read from the disc, currently
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about 150 KBytes/second. This is sufficient for all but uncompressed,
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full motion color video.
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CD Summary Part 2
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CD Data Hierarchy
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Storing data on a CD may be thought of as occurring through a data
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encoding hierarchy with each level built upon the previous one. At the
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lowest level, data is physically stored as pits on the disc. It is
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actually encoded by several low-level mechanisms to provide high storage
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density and reliable data recovery. At the next level, it organized into
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tracks which may be digital audio or CD-ROM. The High Sierra
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specification then defines a file system built on CD-ROM tracks. Finally,
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applications like HyperCard specify a content format for files.
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The Physical Medium
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The Compact Disc itself is a thin plastic disk some 12 cm. in diameter.
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Information is encoded in a plastic-encased spiral track contained on the
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top of the disk. The spiral track is read optically by a noncontact head
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which scans approximately radially as the disk spins just above it. The
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spiral is scanned at a constant linear velocity thus assuring a constant
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data rate. This requires the disc to rotate at a decreasing rate as the
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spiral is scanned from its beginning near the center of the disc to its
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end near the disc circumference.
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The spiral track contains shallow depressions, called pits, in a
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reflective layer. Binary information is encoded by the lengths of these
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pits and the lengths of the areas between them, called land. During
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reading, a low power laser beam from the optical head is focused on the
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spiral layer and is reflected back into the head. Due to the optical
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characteristics of the plastic disc and the wavelength of light used, the
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quantity of reflected light varies depending on whether the beam is on
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land or on a pit. The modulated, reflected light is converted to a radio
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frequency, raw data signal by a photodetector in the optical head.
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Low-level Data Encoding
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To ensure accurate recovery, the disc data must be encoded to optimize the
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analog-to-digital conversion process that the radio frequency signal must
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undergo. Goals of the low level data encoding include:
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1. High information density. This requires encoding that makes the best
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possible use of the high, but limited, resolution of the laser beam and
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read head optics.
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2. Minimum intersymbol interference. This requires making the minimum
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run length, i.e. the minimum number of consecutive zero bits or one bits,
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as large as possible.
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3. Self-clocking. To avoid a separate timing track, the data should be
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encoded so as to allow the clock signal to be regenerated from the data
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signal. This requires limiting the maximum run length of the data so that
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data transitions will regenerate the clock.
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4. Low digital sum value (the number of one bits minus the number of zero
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bits). This minimizes the low frequency and DC content of the data signal
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which permits optimal servo system operation.
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A straightforward encoding would be to simply to encode zero bits as land
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and one bits as pits. However, this does not meet goal (1) as well as the
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encoding scheme actually used. The current CD scheme encodes one bits as
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transitions from pit to land or land to pit and zero bits as constant pit
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or constant land.
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To meet goals (2) to (4), it is not possible to encode arbitrary binary
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data. For example, the integer 0 expressed as thirty-two bits of zero
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would have too long a run length to satisfy goal (3). To accommodate
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these goals, each eight-bit byte of actual data is encoded as fourteen
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bits of channel data. There are many more combinations of fourteen bits
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(16,384) than there are of eight bits (256). To encode the eight-bit
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combinations, 256 combinations of fourteen bits are chosen that meet the
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goals. This encoding is referred to as Eight-to-Fourteen Modulation (EFM)
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coding.
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If fourteen channel bits were concatenated with another set of fourteen
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channel bits, once again the above goals may not be met. To avoid this
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possibility, three merging bits are included between each set of fourteen
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channel bits. These merging bits carry no information but are chosen to
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limit run length, keep data signal DC content low, etc. Thus, an eight
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bit byte of actual data is encoded into a total of seventeen channel bits:
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fourteen EFM bits and three merging bits.
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To achieve a reliable self-clocking system, periodic synchronization is
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necessary. Thus, data is broken up into individual frames each beginning
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with a synchronization pattern. Each frame also contains twenty-four data
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bytes, eight error correction bytes, a control and display byte (carrying
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the subcoding channels), and merging bits separating them all. Each frame
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is arranged as follows:
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Sync Pattern24 + 3channel bits
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Control and Display byte14 + 3
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Data bytes12 * (14 + 3)
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Error Correction bytes 4 * (14 + 3)
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Data bytes12 * (14 + 3)
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Error Correction bytes 4 * (14 + 3)
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TOTAL588channel bits
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Thus, 192 actual data bits (24 bytes) are encoded as 588 channel bits.
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Editorial: A CD physically has a single spiral track about 3 miles long.
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CDs spin at about 500 RPM when reading near the center down to about 250
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RPM when reading near the circumference.
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Disc with a 'c' or disk with a 'k'? A usage has emerged for these terms:
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disk is used for eraseable disks (e.g. magnetic disks) while disc is used
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for read-only (e.g. CD-ROM discs). One would presumably call a frisbee a
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disc.
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--andy
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CD Summary Part 3
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First Level Error Correction
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Data errors can arise from production defects in the disk itself, defects
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arising from subsequent damage to the disk, or jarring during reading. A
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significant characteristic of these errors is that they often occur in
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long bursts. This could be due, for example, to a relatively wide mark on
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the disc that is opaque to the laser beam used to read the disc. A system
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with two logical components called the Cross Interleave Reed-Solomon
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Coding (CIRC) is employed for error correction. The cross interleave
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component breaks up the long error bursts into many short errors; the
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Reed-Solomon component provides the error correction.
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As each frame is read from the disc, it is first decoded from fourteen
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channel bits (the three merging bits are ignored) into eight-bit data
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bytes. Then, the bytes from each frame (twenty-four data bytes and eight
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error correction bytes) are passed to the first Reed-Solomon decoder which
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uses four of the error correction bytes and is able to correct one byte in
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error out of the 32. If there are no uncorrectable errors, the data is
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simply passed along. If there are errors, the data is marked as being in
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error at this stage of decoding.
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The twenty-four data bytes and four remaining error correction bytes are
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then passed through unequal delays before going through another
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Reed-Solomon decoder. These unequal delays result in an interleaving of
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the data that spreads long error bursts among many different passes
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through the second decoder. The delays are such that error bursts up to
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450 bytes long can be completely corrected. The second Reed-Solomon
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decoder uses the last four error correction bytes to correct any remaining
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errors in the twenty-four data bytes. At this point, the data goes
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through a de-interleaving process to restore the correct byte order.
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Subcoding Channels and Blocks
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The eight-bit control and display byte in each frame carries the subcoding
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channels. A subcoding block consists of 98 subcoding bytes, and thus 98
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of the 588-bit frames. A block then can contain 2352 bytes of data.
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Seventy-five blocks are read each second. With this information, it is
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now straightforward to calculate that the CD data rate is in fact correct
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for CD digital audio (CD-DA):
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Required CD digital audio data rate: 44.1 K samples per second * 16 bits
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per sample * 2 channels = 1,411,200 bits/sec.
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CD data rate: 8 bits per byte * 24 bytes per frame * 98 frames per
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subcoding block * 75 subcoding blocks per second = 1,411,200 bits/sec.
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The eight subcoding channels are labeled P through W and are encoded one
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bit for each channel in a control and display byte. Channel P is used as
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a simple music track separator. Channel Q is used for control purposes
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and encodes information like track number, track type, and location
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(minute, second, and frame number). During the lead-in track of the disc,
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channel Q encodes a table of contents for the disk giving track number and
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starting location. Standards have been proposed that would use the
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remaining channels for line graphics and ASCII character strings, but
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these are seldom used.
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Track Types
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Tracks can have two types as specified in the control bit field of
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subchannel Q. The first type is CD digital audio (CD-DA) tracks. The
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two-channel audio is sampled at 44.1 Khz with sixteen bit linear sampling
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encoded as twos complement numbers. The sixteen bit samples are separated
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into two eight-bit bytes; the bytes from each channel alternate on the
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disc. Variations for audio tracks include pre-emphasis and four track
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recording.
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The other type of track specified by the subchannel Q control bit field is
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the data track. These must conform to the CD-ROM standard described
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below. In general, a disc can have a mix of CD digital audio tracks and a
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CD-ROM track, but the CD-ROM track must come first.
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Editorial: This first level error correction (the only type used for CD
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Audio data) is extremely powerful. The CD specification allows for discs
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to have up to 220 raw errors per second. Every one of these errors is
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(almost always) perfectly corrected by the CIRC scheme for a net error
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rate of zero. For example, our tests using Apple's CD-ROM drive (which
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also plays audio) show that raw error rates are around 50-100 per second
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these days. Of course, these are perfectly corrected, meaning that the
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original data is perfectly recovered. We have tested flawed discs with
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raw rates up to 300 per second. Net errors on all of these discs? Zero!
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I would expect a typical audio CD player to perform similarly. Thus I
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expect this raw error rate to have no audible consequences.
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So why did I say "almost always" corrected above? Because a sufficiently
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bad flaw may produce uncorrectable errors. These very unusual errors are
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"concealed" by the player rather than corrected. Note that this
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concealment is likely to be less noticeable than even a single scratch on
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an LP. Such a flaw might be a really opaque finger smudge; CDs do merit
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careful handling. On the two (and only two) occasions I have found these,
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I simply sprayed on a little Windex glass cleaner and wiped it off using
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radial strokes. This restored the CDs to zero net errors.
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One can argue about the quality of the process of conversion of analog
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music to and from digital representation, but in the digital domain CDs
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are really very, very good.
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CD Summary Part 4
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CD-ROM Data Tracks
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Each CD-ROM data track is divided into individually addressable blocks of
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2352 data bytes, i.e. one subcoding block or 98 frames. A header in each
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block contains the block address and the mode of the block. The block
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address is identical to the encoding of minute, second, and frame number
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in subcode channel Q. The modes defined in the CD-ROM specification are:
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Mode 0 -- all data bytes are zero.
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Mode 1 -- (CD-ROM Data):
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Sync Field - 12 bytes
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Header Field - 4
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User Data Field - 2048
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Error Detection Code - 4
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Reserved - 8
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Error Correction - 276
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Mode 2 -- (CD Audio or Other Data):
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Sync Field - 12 bytes
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Header Field - 4
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User Data Field - 2048
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Auxiliary Data Field - 288
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Thus, mode 1 defines separately addressable, physical 2K byte data blocks
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making CD-ROM look at this level very similar to other digital mass
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storage devices.
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Second Level Error Correction
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An uncorrected error in audio data typically results in a brief, often
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inaudible click during listening at worst. An uncorrected error in other
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kinds of data, for example program code, may render a CD unusable. For
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this reason, CD-ROM defines a second level of error detection and error
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correction (EDC/ECC) for mode 1 data. The information for the EDC/ECC
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occupies most of the auxiliary data field.
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The error detection code is a cyclic redundancy check (CRC) on the sync,
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header, and user data. It occupies the first four bytes of the auxiliary
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data field and provides a very high probability that uncorrected errors
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will be detected. The error correction code is essentially the same as
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the first level error correction in that interleaving and Reed-Solomon
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coding are used. It occupies the final 276 bytes of the auxiliary data
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field.
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Editorial: This extra level of error correction for CD-ROM blocks is one
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of the many reasons that CD-ROM drives are much more expensive than
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consumer audio players. To perform this error correction quickly requires
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substantial extra computing power (sometimes a dedicated microprocessor)
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in the drive.
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This is also one reason that consumer players like the Magnavoxes which
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claim to be CD-ROM compatible (with their digital output jack on the back)
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are useless for that purpose. They have no way of dealing with the CD-ROM
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error correction. They also have no way for a computer to tell them where
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to seek.
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Another reason that CD-ROM drives are more expensive is that they are
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built to be a computer peripheral rather than a consumer device, i.e. like
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a combination race car/truck rather than a family sedan. One story,
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probably apocryphal but not far from the truth, has it that a major
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Japanese manufacturer tested some consumer audio players to simulate
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computer use: they made them seek (move the optical head) from the inside
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of the CD to the outside and back again. These are called maximum seeks.
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The story says they managed to do this for about 24 hours before they
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broke down. A CD-ROM drive needs to be several orders of magnitude more
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robust. Fast and strong don't come cheap.
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CD Summary Part 5
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The High Sierra File System Standard
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Built on top of the addressable 2K blocks that the CD-ROM specification
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defines, the next higher level of data encoding is a file system that
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permits logical organization of the data on the CD. This can be a native
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file system like the Macintosh Hierarchical File System (HFS). Another
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alternative is the High Sierra (also known as the ISO 9660) file standard,
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recently approved by the National Information Standards Organization
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(NISO) and the International Standards Organization (ISO), which defines a
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file system carefully tuned to CD characteristics. In particular:
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1. CDs have modest seek time and high capacity. As a result, the High
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Sierra standard makes tradeoffs that reduce the number of seeks needed to
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read a file at the expense of space efficiency.
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2. CDs are read-only. Thus, concerns like space allocation, file
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deletion, and the like are not addressed in the specification.
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For High Sierra file systems, each individual CD is a volume. Several CDs
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may be grouped together in a volume set and there is a mechanism for
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subsequent volumes in a set to update preceding ones. Volumes can contain
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standard file structures, coded character set file structures for
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character encoding other than ASCII, or boot records. Boot records can
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contain either data or program code that may be needed by systems or
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applications.
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High Sierra Directories and Files
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The file system is a hierarchical one in which directories may contain
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files or other directories. Each volume has a root directory which serves
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as an ancestor to all other directories or files in the volume. This
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dictates an overall tree structure for the volume.
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A typical disadvantage in hierarchical systems is that to read a file
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(which must be a leaf of the hierarchy tree) given its full path name, it
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is necessary to begin at the root directory and search through each of its
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ancestral directories until the entry for the file is found. For example,
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given the path name "Wine Regions:America:California:Mendocino", three
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directories (the first three components of the path name) would need to be
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searched. Typically, a separate seek would be required for each
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directory. This would result in relatively poor performance.
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To avoid this, High Sierra specifies that each volume contain a path table
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in addition to its directories and files. The path table describes the
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directory hierarchy in a compact form that may be cached in computer
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memory for optimum performance. The path table contains entries for the
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volume's directories in a breadth-first order; directories with a common
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parent are listed in lexicographic order. Each entry contains only the
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location of the directory it describes, its name, and the location in the
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path table of its parent. This mechanism allows any directory to be
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accessed with only a single CD seek.
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Directories contain more detailed information than the path table. Each
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directory entry contains:
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Directory or file location.
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File length.
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Date and time of creation.
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Name of the file.
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Flags:
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Whether the entry is for a file or a directory.
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Whether or not it is an associated file.
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Whether or not it has records.
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Whether or not it has read protection.
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Whether or not it has subsequent extents.
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Interleave structure of the file.
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Interleaving may be used, for example, to meet realtime requirements for
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multiple files whose contents must be presented simultaneously. This
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would happen if a file containing graphic images were interleaved with a
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file containing compressed sound that describes the images.
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Files themselves are recorded in contiguous (or interleaved) blocks on the
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disc. The read-only nature of CD permits this contiguous recording in a
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straightforward manner. A file may also be recorded in a series of
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noncontiguous extents with a directory entry for each extent.
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The specification does not favor any particular computer architecture. In
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particular all significant, multibyte numbers are recorded twice, once
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with the most significant byte first and once with the least significant
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byte first.
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Multimedia Information
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Using the file system are applications that create and portray multimedia
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information. While it is true that a CD can store anything that a
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magnetic disk can store (and usually much more of it), CDs will be used
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more for storing information than for storing programs. It is the very
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large storage capacity of CDs coupled with their low cost that opens up
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the possibilities for interactive, multimedia information to be used in a
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multitude of ways.
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Programs like HyperCard, with it's ease of authoring and broad
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extensibility, are very useful for this purpose. Hypercard stacks, with
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related information such as color images and sound, can be easily and
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inexpensively stored on CDs despite their possibly very large size.
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Editorial: The High Sierra file system gets its name from the location of
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the first meeting on it: the High Sierra Hotel at Lake Tahoe. It is much
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more commonly referred to as ISO 9660, though the two specifications are
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slightly different.
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It has gotten very easy and inexpensive to make a CD-ROM disc (or audio
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CD). For example, you can now take a Macintosh hard disk and send it with
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$1500 to one of several CD pressers. They will send you back your hard
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disk and 100 CDs with exactly the same content as what's on your disk.
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This is the easy way to make CDs with capacity up to the size of your hard
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disk (Apple's go up to 160 megabytes). True, this is not a full CD but
|
|
CDs don't need to be full. If you have just 10 megabytes and need 100
|
|
copies, CDs may be the best way to go.
|
|
|
|
If you are buying a CD-ROM drive, there are several factors you might
|
|
consider in making your choice. Two factors NOT to consider are capacity
|
|
and data rate. The capacity of all CD-ROM drives is determined solely by
|
|
the CD they are reading. Though you will see a range of numbers in
|
|
manufacturers' specs (e.g. 540, 550, 600, and 650 Mbytes), any drive can
|
|
read any disc and so they are all fundamentally the same. All CD-ROM
|
|
drives read data at a net 150 Kbytes/sec for CD-ROM data. Other data
|
|
rates you may see may include error correction data (not included in the
|
|
net rate) or may be a mode 2 data rate (faster than mode 1). All drives
|
|
will be the same in all of these specs.
|
|
|
|
[ Editorial: The last paragraph is wrong on both points. This may have
|
|
been true in 1988, when this article was written, but is no longer true
|
|
today (in 1992). A few drives cannot read CDROMs with more than about
|
|
620 megabytes on them. There is a huge variation in speed. Today only
|
|
the slowest drives read at 150 kb/sec. Most read at least 300 and at
|
|
least one (the Pioneer DRM-600X) reads at 600 kb/sec. ]
|
|
|
|
===============================================================================
|
|
|
|
**** Reprinted from Atari Explorer Online Volume 2, Issue 1, Januari 1993. ****
|
|
|
|
||| The ALBERT File: CD-ROM & Photo CD ...... Coming to an Atari near you
|
|
||| By: Albert Dayes
|
|
/ | \ CompuServe: 70007,3615 GEnie: AEO.1
|
|
---------------------------------------------------------------------
|
|
|
|
/***********************************************************************
|
|
Title: CD.DOC
|
|
|
|
Created: December 10, 1992
|
|
Last Modified: December 31, 1992
|
|
|
|
Purpose: A Guide to Optical Storage with a special focus on
|
|
CD-ROM and Kodak's Photo CD on the Atari platform.
|
|
|
|
Author: Albert Dayes
|
|
|
|
Legal Notes: Copyright 1992 Albert Dayes, All Rights Reserved
|
|
Some portions Copyright 1992 Rich Bowers, used by
|
|
permission.
|
|
|
|
Version: 1.0
|
|
***********************************************************************/
|
|
|
|
CD-ROM on the Atari Platform NOW!
|
|
|
|
|
|
Atari owners have been waiting with baited breath for CD-ROM to arrive
|
|
on the Atari platform. Actually the CD-ROM portion has been around for
|
|
quite a while but now you can add Photo CD to the long list of tools
|
|
available on the Atari ST, TT030, and Falcon030.
|
|
|
|
This is a guide to CD-ROM in general and what it all means to the user.
|
|
Its purpose is to go beyond the endless lists of terms on optical media
|
|
and CD-ROM and explain how it can work for you. Included is a glossary
|
|
of terms so one can have something to refer to when an unknown term
|
|
appears.
|
|
|
|
Thanks are in order to several people but one in particular is Rich
|
|
Bowers (CO-SYSOP on CD-ROM forum on COMPUSERVE) who provided answers to
|
|
quite a few questions in this document. He does an outstanding job as you
|
|
will notice when you start reading it.
|
|
|
|
/***********************************************************************/
|
|
|
|
Special Thanks to:
|
|
|
|
Steve Luper = Sysop of the CD-ROM forum on COMPUSERVE (GO CD-ROM)
|
|
|
|
Rich Bowers = Co-Sysop of the CD-ROM forum on COMPUSERVE and Executive
|
|
Director of Optical Publishing Association (OPA). Rich
|
|
willingly provided answers to some of the questions in
|
|
this document; specifically questions: A, B, C, D, E,
|
|
which are Copyright 1992 Rich Bowers.
|
|
|
|
Paul McAfee = of Kodak (Press Relations Manager for Photo CD) - for
|
|
all his help with my Photo CD questions. Also for all
|
|
of Kodak's Press Releases dealing with Photo CD.
|
|
|
|
Scott Brownstein = Manager of Advanced Projects at Kodak - for answering
|
|
questions on technical details on CD technology and
|
|
Photo CD.
|
|
|
|
Additional Thanks:
|
|
|
|
Ron Luks = Chief Sysop of the Atari forums on COMPUSERVE (GO ATARI)
|
|
|
|
Paul Wisotzke = of Kodak Information Center (KIC)
|
|
|
|
Joel White = of Kodak Information Center (KIC)
|
|
|
|
/********************************************************************/
|
|
|
|
TABLE OF CONTENTS
|
|
|
|
A) What is CD-ROM?
|
|
B) What is the difference between "disc" and "disk"?
|
|
C) How standardized is CD-ROM?
|
|
D) What is SCSI and why is it important to CD-ROM?
|
|
E) How is CD-ROM related to laserdisc (videodisc)?
|
|
F) What are the CD-ROM standards?
|
|
G) What benefit is CD-ROM to me?
|
|
H) How much does it cost to make my own CD-ROM disc?
|
|
I) What is Kodak's Photo CD?
|
|
J) What is multi-session and why is it important to Photo CD?
|
|
K) Summary of an interview Scott Brownstein - manager of Advanced Projects
|
|
at Kodak.
|
|
L) Which is the best CD-ROM drive to buy for use on the Atari?
|
|
|
|
CONTACTS for ATARI Related CD-ROM and/or PHOTO CD products.
|
|
|
|
ISO-9660 filesystem made EASY
|
|
|
|
MULTI-SESSION made EASY
|
|
|
|
Making My OWN CD-ROM made EASY
|
|
|
|
An Atari Dream CD-ROM
|
|
|
|
GLOSSARY OF TERMS
|
|
|
|
CD-ROM DRIVE MANUFACTURERS
|
|
|
|
SOURCES OF INFORMATION ON OPTICAL MEDIA and SPECIFICATIONS
|
|
|
|
|
|
/*********************************************************************/
|
|
--==-- A) What is CD-ROM?
|
|
|
|
Physically, CD-ROM is the same compact disc that has become the standard
|
|
for the delivery of music. It is a plastic disc, 4-3/4" (12cm) in
|
|
diameter, on which data is recorded digitally. There is also a 3-1/2"
|
|
(8cm) form factor, equivalent to the mini-disc music product (although
|
|
this size is currently used only in Sony's Data DiscMan portable reader).
|
|
Because compact disc is a digital medium, it is a natural for delivery of
|
|
information of a variety of types - text, photos, audio,
|
|
computer-generated graphics, video and software - to a computer host.
|
|
|
|
CD-ROM has many unique features that suit it to information delivery. It
|
|
has a capacity of approximately 650 million characters (about 200 million
|
|
characters for the mini-disc). This capacity is analogous to any number of
|
|
measures. It is equivalent to over 1500 high-density floppies (1.44
|
|
megabyte disk size), or over 200,000 pages of printed text. By using a
|
|
lower sampling frequency for recording audio, it can hold many hours of
|
|
sound. It can hold upwards of 10,000 high quality photographs. By using
|
|
compression and decompression techniques (in partnership with the host
|
|
computer), these numbers can be greatly increased.
|
|
|
|
It is a very durable delivery medium. It is not indestructible, but it is
|
|
not subject to magnetic fields as hard disks are, and it can be mailed
|
|
with minimal protection. The disc itself weighs only an ounce or two, and
|
|
thus is highly portable. Technical standards enable a CD-ROM to be
|
|
"portable," in a computer sense, across many types of systems.
|
|
|
|
Because compact discs are mastered and inexpensively replicated in
|
|
quantity, CD-ROM is an ideal medium for "publishing" many copies of large
|
|
volumes of information. Because the discs are digital and have a high
|
|
capacity, they are amenable to entirely new categories of products - such
|
|
as multimedia - which have not been "published" in the past, because there
|
|
was no practical means to do so.
|
|
|
|
Thus there are large databases that have formerly been accessible only
|
|
online being published, in whole or in part, on CD-ROM. We see multimedia
|
|
presentations, which formerly were only accessible from large magnetic
|
|
discs, being packaged and distributed like other publications. CD-ROM has
|
|
inspired new methods for the delivery of existing materials, it has
|
|
inspired the creation of radically new materials, and it has inspired a
|
|
complete re-thinking of traditional publishing and distribution processes.
|
|
For this reason, we see CD-ROM as the catalyst and the means for a
|
|
"revolution" in publishing.
|
|
|
|
Compact disc was created and defined in a series of proprietary standards
|
|
by a joint effort of Sony and Philips. Compact disc-audio was introduced
|
|
as a commercial product in 1982. The first CD-ROM applications were
|
|
introduced for sale in late 1985. CD-I was announced in 1986, the first
|
|
commercial products were sold in the fall of 1991. CDTV was first sold in
|
|
the spring of 1991. The MPC specification was introduced in 1991, and the
|
|
first MPC-compliant upgrade kits and titles were launched in late 1991. Of
|
|
course, there are new CD-ROM based devices coming from Sony (via the
|
|
handheld Data Discman and the so-called Bookman), Tandy (VIS) and
|
|
cartridge-based game systems producers like Sega, NEC and Nintendo.
|
|
|
|
CD-ROM differs from CD-audio in that certain data are added to meet the
|
|
needs of computer operating systems, and to assure that the data you
|
|
receive are the same as the data originally recorded. To meet the needs of
|
|
a computer's operating system, a header is required that describes the
|
|
nature and location of the data on the disc. This is called a
|
|
volume-table-of contents, or VTOC in computer-ese. The integrity of the
|
|
data is assured through the use of multiple layers of error-correction
|
|
codes, which further distinguish CD-ROM from CD-audio. The structure and
|
|
use of these components are mandated by standards such as the Yellow Book
|
|
(which defines the recording of data for computer use, extending the
|
|
CD-audio standard described in the Red Book), and ISO 9660, an
|
|
international standard that defines the VTOC.
|
|
|
|
Within these constraints, there are many ways to deliver information for
|
|
specific platforms and applications. These differing methods have lead to
|
|
the proliferation of "CD-ROM formats" - such as CD-ROM-XA, CD-I and so
|
|
forth. These are described in detail below. However, all formats conform
|
|
first to the CD-audio standard, second to the CD-ROM standard, and third
|
|
to the extended specifications required for each format. In short, CD-I is
|
|
a format of CD-ROM, CDTV is a format of CD-ROM, etc.
|
|
|
|
CD-ROM requires a computer to read, interpret and display data, and to
|
|
deal with the interactive nature of CD-ROM access and use. The initial
|
|
products were exclusively computer host-based: the drive is attached as a
|
|
peripheral to a personal computer. In recent years, a new category of
|
|
products has emerged: the so-called "information appliances," such as
|
|
CD-I, VIS, Data Discman, etc. These products also use computers, but the
|
|
computer-ness is embedded in the use of the product. The technical aspects
|
|
of many of these products are described below.
|
|
|
|
|
|
--==-- B) What is the difference between "disc" and "disk"?
|
|
|
|
The convention is that "disc" refers to optical media, while "disk" refers
|
|
to magnetic media. The distinction is important, because the different
|
|
spellings signify very different products. Most trade media seem to be
|
|
oblivious to the distinction.
|
|
|
|
By the way, the absolutely correct way of referring to CDROM is "CD-ROM."
|
|
This author and others often remove the hyphen because a) it does not
|
|
change the meaning and b) it is easier to type. CD-ROM should not be
|
|
shortened to "CDR" because CD-R refers to compact disc-recordable
|
|
systems, or CD-Write Once.
|
|
|
|
|
|
--==-- C) How standardized is CD-ROM?
|
|
|
|
CD-ROM is one of the most thoroughly standardized computer sub-systems in
|
|
the history of the business. The medium is standard, and the drives that
|
|
read the medium are defined by standards. The format of the header which
|
|
enables cross-platform access to data - ISO 9660 - is standardized.
|
|
|
|
Not all is perfect, however. CD-ROM developers must do business in the
|
|
real world comprised of a variety of computer platforms, operating
|
|
systems, and other factors. So the information content on a CD-ROM remains
|
|
- to some extent - dependent on the system which will access and use the
|
|
data.
|
|
|
|
|
|
--==-- D) What is SCSI, and why is it important to CD-ROM?
|
|
|
|
The Small Computer System Interface (SCSI - generally pronounced
|
|
"scuzzee"), is a standard which permits the connection of up to 7
|
|
different devices to the host computer. Each device still requires its own
|
|
driver software.
|
|
|
|
The use of SCSI requires an interface board inserted in an expansion slot
|
|
of a PC. Macintosh and UNIX systems are natively SCSI-based. One advantage
|
|
of SCSI is that expansion slots are conserved - instead of a proprietary
|
|
interface board required for each device, several can share the same
|
|
interface. Devices such as scanners, printers, hard drives, CD-R drives
|
|
like Philips CDD-521, MO drives, WORM drives, and some network cards
|
|
(usually ethernet), can use SCSI in addition to CD-ROM drives.
|
|
|
|
Virtually all CD-ROM drive manufacturers have one or more models that are
|
|
SCSI compatible. In most cases, the consumer has a choice of acquiring the
|
|
interface board from the CD-ROM drive vendor, or using a board from a
|
|
third party. At the risk of offending some vendors by exclusion, note that
|
|
interfaces from Adaptec, UltraStor and Future Domain receive many comments
|
|
on the CD-ROM Forum.
|
|
|
|
A new variation on SCSI has emerged. The original standard, now called
|
|
SCSI-1, has been enhanced with a new specification called SCSI-2. SCSI-2
|
|
has standardized audio commands for CD-ROM drives. So using a SCSI-2
|
|
"play" command will work on all SCSI-2 CD-ROM drives, eliminating the need
|
|
for unique audio device drivers for each CD-ROM drive. SCSI-2 is
|
|
backwardly compatible with SCSI-1, so a SCSI-1 device will work with a
|
|
SCSI-2 interface board.
|
|
|
|
In addition, SCSI-2 will offer faster transfer speed for devices that can
|
|
support it, and the capability to transfer 16- and 32-bit paths in
|
|
addition to the normal 8-bits. Standard SCSI connectors have 50 pins, a
|
|
new wide SCSI has a 68-pin connector. SCSI-2 has not been formally
|
|
approved yet, although some vendors are offering products with these
|
|
features.
|
|
|
|
(My thanks to Albert Dayes for providing the majority of this data.)
|
|
|
|
NOTE: The Atari TT is SCSI based and the Atari Falcon030 is SCSI-2
|
|
based, and with Atari and third party host adapters like ICD one
|
|
can have SCSI-1 or SCSI-2 adapters available for use on the Atari
|
|
ST series of computers.
|
|
|
|
|
|
--==-- E) How is CD-ROM related to laserdisc (videodisc)?
|
|
|
|
In the mid-1970's a number of companies introduced a 12" disc product
|
|
which could deliver movies and other graphical/video content superior to
|
|
that of videotape formats. What we know now as the laserdisc, or
|
|
videodisc, has been up, and it has been down, in terms of market
|
|
acceptance. It has been of consistent interest for training and
|
|
educational purposes, because it provided an "interactive" capability for
|
|
the use of video material that tape does not provide. Recently, videodisc
|
|
has seen a resurgence in the consumer marketplace.
|
|
|
|
Laserdisc is an analog format: the data are recorded on the disc just as
|
|
in any other analog medium like video or audio tape. CD-ROM is a digital
|
|
format. Laserdisc gives a superior quality video picture and high quality
|
|
sound. Laserdisc is not a good medium for delivery of text, software or
|
|
manipulatable data elements. Digital video technology is still being
|
|
perfected, but no one would claim that CD-ROM can deliver as a good a tv
|
|
picture as laserdisc.
|
|
|
|
The advantage CD-ROM brings to the table is the ability to mix and match a
|
|
wide variety of data elements through retrieval or authoring software. If
|
|
the sole requirement of the consumer is high-quality video, then laserdisc
|
|
is the right product to buy. If, however, the requirement is for random
|
|
access to large volumes of mixed-format data, a high degree of
|
|
interactivity, or converging published data with other computer
|
|
applications, then CD-ROM is the right product. It is this flexibility
|
|
(albeit with limitations in the video arena) that has captured the
|
|
attention of many new publishers.
|
|
|
|
|
|
--==-- F) What are the CD-ROM standards?
|
|
|
|
The standards have two levels, the physical and logical level. The
|
|
physical defines how the actual disc is made (size, material, etc). The
|
|
logical defines how a device driver or operating system will view the data
|
|
that is placed on the disc.
|
|
|
|
There is a broad standard that gives the physical characteristics of the
|
|
disc and this is called the "Yellow Book." The "Yellow Book" defines all
|
|
the physical requirements for any CD-ROM disc. The "Yellow Book" has
|
|
everything basically that the "Red Book" has and more. Audio CDs are
|
|
defined by the "Red Book," and the "Yellow Book" allows for CD-ROM to have
|
|
either data or audio tracks or a hybrid that allows for both types of
|
|
tracks on a CD-ROM. This hybrid is usually referred to as mixed mode.
|
|
|
|
The logical format one can also think of as the filesystem of the CD-ROM.
|
|
In the 1986 the High Sierra format was made and when the ISO
|
|
(International Standards Organization) modified it became the ISO-9660
|
|
standard. This ISO-9660 standard is very important since it allows for any
|
|
type of system to be able to read it. Platform independence was one of the
|
|
very important features of the ISO-9660 standard. One does notice that it
|
|
has a strong MS-DOS influence in its overall design and in some of the
|
|
limits.
|
|
|
|
It is important to note that logical format can be any filesystem and does
|
|
not necessarily mean ISO-9660. For example some discs are in Apple
|
|
Macintosh HFS (Hierarchical File System) rather than ISO-9660.
|
|
|
|
CD-ROM/XA allows everything listed above and it added a compressed audio
|
|
capability. Also, the layouts of the tracks on the physical disc have been
|
|
modified to allow for more specific track information. CD-I and Photo CD
|
|
are built on top of this enhancement to CD-ROM. The audio is ADPCM and it
|
|
is interleaved with data. This allows for nicely synchronized audio
|
|
without taking away CPU time. It is not used very much currently but this
|
|
may change in the future.
|
|
|
|
Rich Bowers, Executive Director of the OPA sums it up nicely.
|
|
|
|
Its primary purpose was to interleave audio with other data, in effect
|
|
to synchronize audio with a visual presentation. Think in terms of
|
|
making the sound come out in synch with the lips moving.
|
|
|
|
When you consider it, there are basically two kinds of data: those
|
|
which are time-sequence dependent and those which are not. A database
|
|
retrieval or the presentation of a single graphic is independent of
|
|
other data from a time perspective. Audio is absolutely tied to a
|
|
time-sequence. Video data is also dependent on time-sequencing,
|
|
although we have some freedom in representing motion because the
|
|
psychological phenomenon that lets us fill in the blanks in our minds,
|
|
in essence to see things that aren't there. Audio is less flexible
|
|
that way.
|
|
|
|
XA is a physical means of storing data that depends on the
|
|
time-sequencing of related data. A new standard called HyTime (about
|
|
which I hope to have a file uploaded soon) is a production technique
|
|
for dealing with time-sequenced data, based on the SGML mark-up
|
|
strategy.
|
|
|
|
|
|
Rock Ridge extensions to the ISO-9660 standard allow all the features of
|
|
the UNIX filesystem to be used. These extra information is stored the
|
|
System Use fields defined in the ISO-9660 standard. The information that
|
|
is stored there for UNIX/POSIX include uid, gid, permissions, file mode
|
|
bits, file types, setuid, setgid, sticky bit, file links, device nodes,
|
|
symbolic links, POSIX filenames, reconstruction of deep directories and
|
|
time stamps.
|
|
|
|
|
|
--==-- G) What benefit is CD-ROM to me?
|
|
|
|
The benefits can be quite numerous once you start listing all of them.
|
|
First we can discuss some of the possible uses for CD-ROMs.
|
|
|
|
Desk Top Publishing = Large amount of clip art, fonts and images can be
|
|
& Graphic Designers found for relatively low cost from many vendors.
|
|
Kodak Photo CD's can have a great impact in this
|
|
area as well.
|
|
|
|
Musicians & = CD-ROM discs can hold a huge amount of different
|
|
Audio Engineers samples and sound effects covering a large range
|
|
of topics at a very reasonable cost. Generic
|
|
sequences for MIDI will also be available in the
|
|
future.
|
|
|
|
Writers = Reference materials including dictionaries,
|
|
quotations and complete works by a large variety
|
|
of authors on one disc.
|
|
|
|
Programmers = Walnut Creek has 600 megabytes of source code for
|
|
under $40. Being able to store all that source
|
|
code in a concise place is a major benefit of
|
|
CD-ROM. One can get C source code which includes
|
|
a part of BSD UNIX (including the networking code),
|
|
X-Windows (X11R5), and entire GNU source code for
|
|
under $50. The entire library of the C USERS
|
|
JOURNAL plus all of the program source code
|
|
listings in the magazine (since 1987) for $50.
|
|
|
|
Marketing Managers = Census data can be purchased on CD-ROM in a raw
|
|
ascii data format and can be loaded into a database
|
|
or spreadsheet for endless "what if" type of
|
|
manipulation. Also there are many CD-ROMs that
|
|
target specific geographical regions that can be
|
|
very useful for niche markets.
|
|
|
|
Space Exploration = One can purchase CD-ROMs from the different space
|
|
missions for under $10 each from the NASA Space
|
|
Science Data Center.
|
|
|
|
Geology and = The US Geological survey has quite a few CD-ROMs
|
|
Mapping consisting of the entire USA or specific geographical
|
|
regions for quite a low cost. One interested in
|
|
graphics could generate some nice 3D graphic models.
|
|
|
|
Games = Games are coming to CD-ROM slowly but surely.
|
|
|
|
Health Providers = Important Medical Journals, and medical research
|
|
papers are available now on CD-ROM.
|
|
|
|
Lawyers = There are a few CD-ROMs of all the laws for specific
|
|
states and even compilations from West Publishing,
|
|
one of the largest law publishers which also includes
|
|
an on-line service for lawyers.
|
|
|
|
Optical Publishing = Custom designed CD-ROMs that contain complete
|
|
specifications and documents is a very strong
|
|
growing area of the CD-ROM market. This also
|
|
includes multi-media titles as well and much
|
|
more.
|
|
|
|
Education = Interactive learning using multi-media on CD-ROMs.
|
|
Research papers and much more are available in this
|
|
exploding market.
|
|
|
|
Religion = The Bible (in many versions), Koran and many other
|
|
works from different religions all on one disc.
|
|
|
|
Family Album = Store all the family pictures on a single disc using
|
|
Photo CD.
|
|
|
|
Anyone = Archiving important data for later retrieval. This
|
|
data can be anything: financial, marketing, C source
|
|
code, software, games, papers, audio, etc.
|
|
|
|
General = There is a tremendous amount of information on
|
|
CD-ROM discs in just plain ASCII format that anyone
|
|
can use with their computer. Just import it into
|
|
a word processor, spreadsheet or database and
|
|
there are endless possibilities.
|
|
|
|
One could go on and on about the possibilities.
|
|
|
|
|
|
What types are available for the Atari currently?
|
|
|
|
All discs that are ISO-9660 compliant and contain raw data, sound, clip
|
|
art, images, etc, can be used on the Atari immediately. Currently there
|
|
are not any CD-ROMs specifically designed for the Atari ST except for a
|
|
couple that include many different shareware programs. You can not run
|
|
programs on CD-ROMs designed for other platforms like the IBM PC or the
|
|
MAC; it just like attempting to run a PC program from your Atari... it
|
|
won't work.
|
|
|
|
This will change once more people get CD-ROM drives on the Atari and start
|
|
asking for titles. The Atari Falcon030 and the TT030 have both been to
|
|
shown to work with Kodak's Photo CD at the recent Fall 1992 Comdex show.
|
|
It was working directly with an application (a DeskTop Publishing program)
|
|
called Calamus SL.
|
|
|
|
The key here is the hardware and software is available to use CD-ROMs on
|
|
the Atari is available NOW! Both Atari and ICD have drivers available that
|
|
work with SCSI CD-ROM drives.
|
|
|
|
|
|
--==-- H) How much does it cost to produce my own CD-ROM disc?
|
|
|
|
One can take 600 megabytes of a hard disk and save it to tape, then send
|
|
to some specific publishers and they will convert it to a single CD-ROM
|
|
for $200. One could probably use Beckemeyer's SCSI TAPE KIT or Oregon
|
|
Research Associates Diamond Back III to perform that operation.
|
|
|
|
One should check to be sure that the publisher can handle the current tape
|
|
format. The format usually used is TAR. TAR allows for files to be backed
|
|
up and restored on many different platforms. In addition, it can split
|
|
large files and each tape is independent of the other tapes when it comes
|
|
to restoration.
|
|
|
|
If one wants to be able to create One-Offs or CD-WO discs one needs to
|
|
spend around $12,000 for everything one would need. Then you can create
|
|
your own discs at your convenience and then send it off to the duplicator
|
|
for more copies when you need to. The CD-WO media is under $50 so it isn't
|
|
too expensive from a media point of view.
|
|
|
|
The most expensive part of the creating One-Offs is CD-Writer itself which
|
|
ranges from around $7000 and up depending on the features available.
|
|
These devices are usually SCSI devices and create a CD disc (audio or
|
|
data) in about 30 to 70 minutes on average. The software to create a disc
|
|
image (usually called the pre-mastering phase) is around $2500 and up.
|
|
Plus a computer to handle all of that can be $3000 and up. Prices are
|
|
dropping all the time so it might now be too long before many people have
|
|
personal CD-Writers.
|
|
|
|
|
|
--==-- I) What is Kodak's Photo CD?
|
|
|
|
Is a new standard based upon an extension CD-ROM/XA specification since
|
|
it adds additional information at the track level. This new format is
|
|
called the CD-Bridge format and it is what Kodak's Photo CD is based on.
|
|
|
|
The Photo CD system, jointly developed by Eastman Kodak Company
|
|
and Philips stores 35-mm photographs as well as text, graphics
|
|
and sound on compact discs. It offers several benefits to
|
|
consumers and professionals:
|
|
|
|
* rapid retrieval and display of images
|
|
|
|
* consistent and optimum image quality
|
|
|
|
* access to powerful image manipulation
|
|
|
|
* access to high-quality, continuous tone printing
|
|
|
|
* support for a wide range of colors;
|
|
|
|
* image duplication without degradation
|
|
|
|
* support for current and future television formats
|
|
|
|
|
|
How much does it cost to get my film on a Photo CD?
|
|
|
|
The average cost is around $24 for an average roll of film. One gets the
|
|
negatives, prints and a Photo CD. One should contact their local
|
|
photofinisher or Kodak for the location of the one in your area.
|
|
|
|
The picture resolutions range from 128 x 192 to 2048 x 3072 and all 5
|
|
resolutions are in 24-bit color. How big is image of the highest
|
|
resolution? It is around 20 megabytes in size. One can place between 100
|
|
- 150 images (PAC) on a MASTER Photo CD. Software is available on
|
|
computers that can convert these formats to a compatible graphic standard
|
|
(ie GIF, TIFF, TARGA, etc). The five picture formats that are included in
|
|
each image PAC are as follows:
|
|
|
|
Image Resolution
|
|
==========================
|
|
|
|
Base/16 = 128 x 192 pixels
|
|
Base/4 = 256 x 384 pixels
|
|
Base = 512 x 768 pixels
|
|
4Base = 1024 x 1536 pixels
|
|
16Base = 2048 x 3072 pixels
|
|
|
|
In image PAC is a compressed form that includes all 5 resolutions of a
|
|
single image and ranges from 4 to 6 megabytes on average. When used in a
|
|
program, the image is decompressed so that it can be displayed.
|
|
|
|
Stand-alone Photo CD players will play both standard audio CDs and display
|
|
Photo CD images on the television screen. Anyone will be able to enlarge
|
|
and manipulate the Photo CD images on a television to create custom Photo
|
|
CD albums with the players. Kodak's Photo CD players and Philips CD-I
|
|
players both work quite nicely.
|
|
|
|
|
|
For use with a CD-ROM on a computer system one needs to have the following:
|
|
|
|
* CD-ROM/XA (mode 2 from 1 sectors) and CD-BRIDGE format compatibility
|
|
* Display system (24-bit color is recommended for best results)
|
|
* Software driver that can read/access Photo CD discs.
|
|
|
|
In the future, Kodak Photo CD logos will be placed on compatible drives.
|
|
|
|
|
|
How is a photograph placed on a Photo CD?
|
|
|
|
* KODAK PCD Film Scanner digitizes 35-mm negatives or slides. The film is
|
|
scanned at a minimum resolution of 2048 x 3072. The three RGB values
|
|
(primary colors Red, Green, and Blue) are given 12-bits each for color
|
|
values.
|
|
|
|
* Image data is encoded and color adjustments are performed in addition to
|
|
compression. This is all done to achieve consistent, high quality
|
|
prints. The image color is reduced to 24-bits.
|
|
|
|
* The digitized image is then written to a Photo CD disc. It is written to
|
|
disc via CD-Writer device.
|
|
|
|
/**** A Graphical view of the Kodak Photo CD Finishing Process ****/
|
|
|
|
PCD = Photo CD
|
|
|
|
|
|
[ EXPOSED FILM ]
|
|
|
|
|
|
|
|
[ FILM PROCESS ] -> [ PRINTER/PAPER PROCESS ]
|
|
| |
|
|
| |
|
|
[Negatives (or Slides)] [ CONSUMER PRINTS]
|
|
|
|
|
|
|
|
[KODAK PCD Film Scanner]
|
|
|
|
|
|
|
|
[KODAK PCD Data Manager (computer)] -> [KODAK PCD Printer]
|
|
| |
|
|
| |
|
|
[KODAK PCD WRITER ] [KODAK Index Print]
|
|
|
|
|
|
|
|
|
|
|
[ Kodak Photo CD disc ]
|
|
|
|
|
|-------|------------------------------------|
|
|
| |
|
|
| |
|
|
| |
|
|
Home TV Viewing Personal Compututing
|
|
| |
|
|
| |
|
|
[Kodak Photo CD Player] [CD-ROM (XA, Multi-Session) ]
|
|
|
|
|
|
One can find out more information on Photo CD by contacting
|
|
the Kodak Information Center (KIC).
|
|
|
|
|
|
--==-- J) What is multi-session and why is it important to Photo CD?
|
|
|
|
Multi-Session is the ability to read more than one table of contents. One
|
|
can think of a book when thinking of table of contents. A single session
|
|
drive can only read one session. This is similar to a 10 chapter book and
|
|
only being able to read the first chapter. With multi-session, one can
|
|
read all sessions that were written at different times. If this were a
|
|
book you would be able to read all 10 chapters.
|
|
|
|
The advantage of multi-session is being able to place photographs taken at
|
|
different times. For example if one takes pictures during summer vacation
|
|
they can be placed on a Photo CD disc. At Christmas time you take more
|
|
pictures and they can be added to the disc as well. Every time one adds a
|
|
new set of pictures to a disc it is called a session. So one can see what
|
|
a useful feature Multi-Session capability is.
|
|
|
|
NOTE: Multi-Session works with all forms of CD-ROM data including Kodak's
|
|
Photo CD. So having multi-session one is not limited to the types of
|
|
data that can be added to the disc later on.
|
|
|
|
|
|
--==-- K) Interview with Scott Brownstein - Manager Advanced Projects at
|
|
Kodak (summary of the interview)
|
|
|
|
AD = Albert Dayes
|
|
SB = Scott Brownstein
|
|
|
|
|
|
AD: How long was the development process for Photo CD?
|
|
SB: Approximately 5 years.
|
|
|
|
AD: Ending in January 1992?
|
|
SB: Yes
|
|
|
|
AD: What computer was used for the development of Photo CD?
|
|
SB: Many different types ranging from MACs to VAX clusters to
|
|
Sun SPARCstations, etc.
|
|
|
|
AD: There are currently only 5 formats for Photo CD including
|
|
Master, PRO, Catalog, Medical and Portfolio.
|
|
|
|
NOTE: a general overview of the different formats was not part
|
|
of the interview.
|
|
|
|
MASTER format has a pac format with 5 different resolutions and can
|
|
store about 100 to 150 images.
|
|
|
|
PRO format which has higher resolution and supports larger film
|
|
formats other than 35-mm. These include 70mm, 120mm and 4 x 5 inch,
|
|
etc.
|
|
|
|
CATALOG format has low resolution than base images and can contain up
|
|
to 6000 images.
|
|
|
|
MEDICAL format is for storing CT (Computed Tomography) and MRI
|
|
(Magnetic Resonance Imaging) pictures in addition to standard film
|
|
formats. It can also be used for other diagnostic scans like
|
|
Ultrasound, PET (Positron Emission Tomographic) and Angiogram.
|
|
|
|
PORTFOLIO format allows the mixing of images, text and audio and
|
|
branching capability, all on one disc. These images are base
|
|
resolution.
|
|
|
|
END NOTE:
|
|
|
|
AD: How does the Catalog format work?
|
|
SB: It contains about 800 video pages and each page can have multiple
|
|
images on it. Each image has an index and can be used to present a
|
|
presentation. Using indexes and branching one can generate a unique
|
|
presentation.
|
|
|
|
Using Kodak's Shoebox software you can find any image by using a
|
|
keyword search. The Shoebox software works with smaller storage
|
|
requirements all the way up to very large jukeboxes with a capability
|
|
of over 100 Photo CD discs on-line at one time.
|
|
|
|
AD: And the Portfolio?
|
|
SB: It allows for the mixing of text, audio and images and Kodak will have
|
|
authoring tools out in 1993. The audio in this case can be either CD
|
|
audio (Red Book) or ADPCM. The branching is just an access method and
|
|
in this case interactive programmed access.
|
|
|
|
AD: What makes the PRO format different from the MASTER format?
|
|
SB: The PRO format can use film sizes larger than 35-mm and allows for a
|
|
max resolution of 8,000 x 12,000. It also has data encryption and
|
|
security features. For example watermarking. Each image can be given
|
|
its own unique key to effectively lock the image.
|
|
|
|
The watermark allows for the picture to display but have a message
|
|
across it like "PROOF" or "COPYRIGHT 1992", etc. So without knowing
|
|
the key this watermark will always be displayed on top of the image.
|
|
Once the person uses the correct key then the watermark will be
|
|
removed from the image being displayed.
|
|
|
|
AD: Are images scanned at 24-bit resolution?
|
|
SB: No, they are scanned at 12-bits per RGB (Red, Green and Blue values).
|
|
The software then compresses it to 24-bits.
|
|
|
|
The 24-bits is actually made up of 8-bits for luminance and the rest
|
|
for chroma.
|
|
|
|
AD: What is Kodak's Picture Exchange?
|
|
SB: Basically it allows people to store images on a consignment basis.
|
|
The fees are based on storage, referral and cross platform.
|
|
|
|
AD: How does one access Kodak's Picture Exchange?
|
|
SB: Anything with 9.6 (9600 baud) and higher can have access.
|
|
|
|
AD: What has been the response to Photo CD?
|
|
SB: It has been extremely positive. Having cross platform capability and
|
|
ISO-9660 helps quite a bit. In addition it reaches both the low and
|
|
the high end with the same technology. Also with Kodak providing
|
|
automatic scanning equipment speeds up the process of translating film
|
|
to Photo CD discs.
|
|
|
|
AD: What about multi-session? Are all of Kodak's Photo CD players
|
|
multi-session?
|
|
SB: Yes all Kodak's Photo CD players are multi-session and so are CD-I
|
|
players. The newer CD-ROM drives are also getting that capability as
|
|
well. In addition they can all play regular audio CDs.
|
|
|
|
AD: What about CD-WO and multi-session?
|
|
SB: This entire area of CD technology is very exciting. So instead of
|
|
being stuck with a 100 megabyte CD you can now add to it. One can add
|
|
any type of data because of multi-session technology. Since there is
|
|
no blank spaces between the data after the drive reads it, it will
|
|
think that it has just a larger CD-ROM. Normal CD-audio will not work
|
|
since it is not part of the specification. It is a problem with audio
|
|
CDs needing TOCs. But if the audio is recorded in the first session it
|
|
will be fine.
|
|
|
|
The advantage of this technology is 1) it is WRITABLE and 2) it is
|
|
PRESSABLE. Consider the low cost of floppy disks but then think of
|
|
long it takes to write data to one. Once you have a CD you can just
|
|
have them pressed. The average time to press a CD is about 4 to 6
|
|
seconds or approximately 100 megabytes per second. It makes perfect
|
|
distribution and duplication sense. With a recordable CD it is almost
|
|
the same as having a 600 megabyte floppy.
|
|
|
|
AD: What is the most important aspect of Kodak Photo CD technology?
|
|
SB: Actually there are three things:
|
|
a) cross platform
|
|
b) digital audio and digital video
|
|
c) high end (PRO market) and low end (Consumer market)
|
|
|
|
AD: Thank you
|
|
|
|
|
|
--==-- L) Which is the best CD-ROM drive to buy?
|
|
|
|
First thing it must be a SCSI CD-ROM drive! If you just want to read data
|
|
disks you can buy one of the older generation drives. Make sure that the
|
|
maker of the driver software has tested your drive so you will not be
|
|
stuck when it doesn't work. In this case contact ICD or Atari. Also if you
|
|
need Photo CD compatibility you need one that is both multi-session and
|
|
CD-ROM/XA compatible. Most of these new drives are either just becoming
|
|
available or will be coming out in early 1993. Price range is under $800.
|
|
|
|
The drivers for regular CD-ROMs are available from Atari and ICD. One
|
|
should contact either of the two companies for additional information.
|
|
|
|
At COMDEX, in the Atari Booth the CD-ROM drive being used for Photo CD was
|
|
a Toshiba TXM3301B1. This is a single-session model and software at the
|
|
time was only single session.
|
|
|
|
Currently the software only supports MULTI-SESSION on the TT030 and Atari
|
|
Falcon030, and only SINGLE session on the ST. It is a possibility that
|
|
multi-session capability will work on the ST in the future. Michael
|
|
Bernards wrote the driver software for Photo CD on the Atari and Calamus
|
|
SL (DTP) Photo CD access software.
|
|
|
|
Calamus SL has an Photo CD importer that supports all five resolutions of
|
|
an image.
|
|
|
|
One should contact the references given below for additional information
|
|
on availability of the Photo CD drivers. Kodak certifies CD-ROM drives
|
|
that are compatible with Photo CD as well. The best method is to ask on an
|
|
on-line service and consult magazines or call the Kodak Information
|
|
Center. Also consult with the maker of driver software since they usually
|
|
have a compatibility list of drives they have tested as well.
|
|
|
|
Toshiba, Pioneer, Sony and other have stated they will have CD-ROM drives
|
|
that will support CD-ROM/XA, multi-session and Photo CD.
|
|
|
|
The current CD-ROM/XA, multi-session Photo CD compatible drive from
|
|
Toshiba is TXM3301E1. This one is the only one currently shipping.
|
|
Upgrades from earlier versions of the TXM3301 are possible (depending on
|
|
serial number) contact Toshiba for more information.
|
|
|
|
The year 1993 is not only the year of the Atari Falcon030 but the year of
|
|
the CD-ROM/XA multi-session CD-ROM drives. Many will be coming out all
|
|
during the 1993 year and prices are dropping!
|
|
|
|
|
|
RECOMMENDATION: Buy a CD-ROM/XA multi-session SCSI drive. The cost is not
|
|
that much higher than normal SCSI drives and you will be
|
|
able to enjoy a long future with Photo CD and CD-ROM.
|
|
|
|
Summary:
|
|
|
|
For general use:
|
|
|
|
1) SCSI CD-ROM drive (external)*
|
|
2) SCSI host adapter (TT030 and Atari Falcon030 have built in SCSI ports.
|
|
The ST family requires SCSI host adapters like
|
|
ICD).
|
|
3) SCSI driver software that supports CD-ROM drives. **
|
|
4) SCSI cables and power cables as needed.
|
|
|
|
For multi-session, and Photo CD support:
|
|
|
|
1) SCSI CD-ROM/XA, multi-session and Photo CD (external)*
|
|
2) SCSI host adapter (TT030 and Atari Falcon030 have built in SCSI ports.
|
|
The ST family requires SCSI host adapters like
|
|
ICD). ****
|
|
3) SCSI driver software that supports CD-ROM drives. **
|
|
4) SCSI driver software for Photo CD support.***
|
|
5) SCSI cables and power cables as needed.
|
|
|
|
|
|
* Internal drives are possible but require additional work. Contact your
|
|
dealer for more information.
|
|
|
|
** Be sure your CD-ROM drive has been tested with CD-ROM driver software
|
|
before purchasing one.
|
|
|
|
*** Be sure your CD-ROM drive has been tested with both the CD-ROM driver
|
|
software and Photo CD software before purchasing one.
|
|
|
|
**** The Photo CD software driver for the ST is currently single session
|
|
only.
|
|
|
|
|
|
/*********************************************************************/
|
|
CONTACTS for ATARI related CD-ROM and PHOTO CD products.
|
|
|
|
|
|
Atari Corporation
|
|
1196 Borregas Ave.
|
|
P.O.Box 61657
|
|
Sunnyvale, CA 94088
|
|
USA
|
|
(408) 745-2000
|
|
|
|
They also can be contacted on GEnie.
|
|
|
|
Products: MetaDOS, CD-ROM drivers, Photo CD drivers, Developer
|
|
information, Photo CD developers' kit
|
|
|
|
|
|
|
|
Beckemeyer Development Tools
|
|
P.O.Box 21575
|
|
Oakland, CA 94620
|
|
(510) 530-9637
|
|
(510) 530-0451 (fax)
|
|
|
|
Products: Hard disk backup, optimization software, SCSI Tape backup
|
|
software
|
|
|
|
|
|
ICD
|
|
1220 Rock Street
|
|
Rockford, IL 61101-1437
|
|
USA
|
|
(800) 373-7700 (orders)
|
|
(815) 968-2228
|
|
(815) 968-6888 fax
|
|
|
|
COMPUSERVE: Atari Vendors forum (GO ATARIVEN)
|
|
GENIE: ICD RoundTable
|
|
|
|
Products: SCSI Host Adapters, SCSI Driver Software and CD-ROM driver
|
|
software
|
|
|
|
|
|
DMC PUBLISHING
|
|
2800 John Street, Suite 10
|
|
Markham, Ontario L3R 0E2
|
|
CANADA
|
|
(416) 479-1880
|
|
(416) 479-1882 (fax)
|
|
(was ISD Marketing at one time)
|
|
|
|
GEnie: ISD
|
|
COMPUSERVE: Atari Vendors forum (GO ATARIVEN)
|
|
DELPHI: ISDMARKETING
|
|
|
|
Products: Photo CD importer for Calamus SL (DTP) supporting all 5
|
|
resolutions.
|
|
|
|
|
|
Oregon Research Associates
|
|
16200 S.W. Pacific Highway, Suite 162
|
|
Tigard, OR 97224
|
|
(503) 620-4919
|
|
(503) 639-6182 (fax)
|
|
|
|
GEnie: ORA.TECH
|
|
|
|
Products: Hard disk backup and optimization software, SCSI Tape backup
|
|
software
|
|
|
|
|
|
/*************************************************************************/
|
|
ISO-9660 filesystem made EASY
|
|
|
|
|
|
This is a very simple filesystem and it very easy to understand. The first
|
|
thing that happens it sector #16 is read. It then checks for the primary
|
|
volume descriptor.
|
|
____
|
|
1-2-3-4-5-6-7-8-9-10-11-12-13-14-15- |16| <----------
|
|
---- |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Check sector 16 for a Primary Volume Descriptor ------
|
|
|
|
If Sector 16 contains the Primary Volume Descriptor then jump to the root
|
|
directory. The root directory is given as an absolute sector number within
|
|
the primary volume descriptor.
|
|
|
|
PRIMARY_VOLUME_DESCRIPTOR
|
|
{
|
|
ID = "CD001";
|
|
other information;
|
|
location of root directory on the disc; ----
|
|
size of root directory; |
|
|
other information; |
|
|
} |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
ROOT DIRECTORY <-------------------------------
|
|
|
|
The root directory contains the list of files and sub-directories. All
|
|
files and directories on an ISO-9660 CD-ROM are called directory records.
|
|
|
|
Here is an example of a root directory:
|
|
|
|
file_1.txt;1 <----- file
|
|
file_2.doc;3 <------------- file
|
|
sub_dir.;2 <----- sub directory
|
|
|
|
If we want to examine file_1.txt;1 and we read the directory record. The
|
|
directory record indicates what sector (absolute) that the file starts on
|
|
and how long the file is in bytes.
|
|
|
|
FILE_1.TXT;1
|
|
{
|
|
other information;
|
|
location of file on the disc;-----------------
|
|
size of the file (in bytes or characters); |
|
|
} |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
data for the file <------------------------------
|
|
|
|
Now suppose we want to go to the sub-directory named sub_dir.;2
|
|
|
|
SUB_DIR.;2
|
|
{
|
|
other information;
|
|
location of sub directory on the disc;-----------------
|
|
size of the sub directory (in bytes or characters); |
|
|
} |
|
|
|
|
|
|
|
|
data for sub directory <----------------------------------
|
|
|
|
The data for this sub-directory is different than the file. The data is a
|
|
list of all the files and sub directories in the directory. The size of
|
|
this sub-directory is given by its length in bytes.
|
|
|
|
An example of the data in the sub-directory;
|
|
|
|
. <---- current sub-directory
|
|
.. <---- parent directory of this sub-directory named sub_dir.;2
|
|
file_99.doc;1
|
|
|
|
To read the file_99.doc;1 one uses the same method out-lined earlier to
|
|
get to file_1.txt;1.
|
|
|
|
The question is now how do we get back to the parent directory? We read
|
|
the ".." directory record. Then jump to the location (absolute) sector of
|
|
the current directory's parent which in this case is the root directory.
|
|
|
|
..
|
|
{
|
|
other information;
|
|
location of parent directory; ----|
|
|
size of parent directory; |
|
|
} |
|
|
|
|
|
|
|
|
parent directory data <---------------
|
|
|
|
The parent directory is read and its contents displayed. In this case the
|
|
parent directory is the root directory.
|
|
|
|
file_1.txt;1 <----- file
|
|
file_2.doc;3 <------------- file
|
|
sub_dir.;2 <----- sub directory
|
|
|
|
We are back to where we started again. It is not very hard to follow it at
|
|
all. It very similar to the filesystem in our Atari and IBM PC computers,
|
|
you might have noticed.
|
|
|
|
The filenames and sub-directory names look strange. Basically the
|
|
filenames are the same type as on the Atari. Its 8.3 format (for example
|
|
ATARI456.DOC) is very familiar. There is some extra characters on the end
|
|
and they add a version number. For example on some computers like
|
|
Digital's VAX every time you save the file the version number is updated.
|
|
|
|
For Example:
|
|
|
|
file.dat;1
|
|
|
|
save the file again
|
|
|
|
file.dat;2 <----- version number is updated after the file is saved.
|
|
|
|
Other than a few small things, ISO-9660 and the Atari filesystem are very
|
|
similar. As one can see the ISO-9660 CD-ROM filesystem is even simpler
|
|
than the normal Atari filesystems. For more technical details on the
|
|
ISO-9660 standard one needs to buy the ISO-9660 specification since it is
|
|
copyrighted by ISO.
|
|
|
|
|
|
/*********************************************************************/
|
|
MULTI-SESSION made EASY
|
|
|
|
|
|
When the CD-ROM drive first spins up it checks for the presence of a TOC
|
|
(table of contents) on the CD. This gives information about how big the
|
|
disc is in general terms. The first TOC is always in the same location so
|
|
all CD-ROM drives and Audio CD players check for its presence everytime
|
|
they are turned on.
|
|
|
|
With Multi-Session the entire disc has to be checked to see if more than
|
|
one session exists. The disc has a beginning and ending for each session
|
|
on the disc. So on a multi-session disc there will be several TOCs and
|
|
beginning and ending sections one for each session. The beginning and
|
|
ending sections are usually referred to lead in and lead out.
|
|
|
|
LI = (lead in) beginning
|
|
LO = (lead out) end
|
|
TOC = Table Of Contents (which is actually part of the lead in section)
|
|
|
|
/*-------------------------------------------------------------------*/
|
|
|
|
SINGLE session disc:
|
|
|
|
LI-TOC-INFORMATION-LO
|
|
|
|
/*--------------------------------------------------------------------*/
|
|
|
|
MULTI-session disc:
|
|
|
|
LI-TOC-INFORMATION-LO (session 1)
|
|
LI-TOC-INFORMATION-LO (session 2)
|
|
LI-TOC-INFORMATION-LO (session 3)
|
|
LI-TOC-INFORMATION-LO (session 4)
|
|
.
|
|
.
|
|
LI-TOC-INFORMATION-LO (session n)
|
|
|
|
/*-------------------------------------------------------------------*/
|
|
|
|
Who says CD-ROM/XA multi-session drives tell the truth?
|
|
|
|
The CD-ROM/XA multi-session drive looks at a disc and reads the first
|
|
Table Of Contents. The software driver asks if the CD-ROM/XA
|
|
multi-session drive has found the end yet. The CD-ROM drive lies and says
|
|
no and continues searching until it finds the last TOC on the disc. The
|
|
CD-ROM/XA multi-session drive replies with a YES when has found the last
|
|
session on the disc.
|
|
|
|
The best part about a multi-session is that one can add data at any time
|
|
whenever one needs to. It will be a great way to make updates to the
|
|
family album using a Photo CD disc as one's album. So many possibilities
|
|
and all available on the Atari too.
|
|
|
|
|
|
/************************************************************************/
|
|
Making My OWN CD-ROM made EASY
|
|
|
|
Walnut Creek provides a service to make a master CD-ROM for only $200.
|
|
They will take 600 megabytes on TAPE or floppies. Yes floppies disks are
|
|
accepted provided they are in MS-DOS format. Strange thing is Atari format
|
|
is the same as MS-DOS format. Does that give any one any ideas? <HINT,
|
|
HINT>
|
|
|
|
And with a Multi-Session CD-ROM/XA drive you can always add more data
|
|
later on to the disc.
|
|
|
|
|
|
/********************************************************************/
|
|
An Atari Dream CD-ROM
|
|
|
|
A dream CD-ROM for me would be to have all the articles in STart, ST-LOG,
|
|
ST-Applications, and Antic all on one CD-ROM. Just think all of those
|
|
articles and program listings in the palm of your hand.
|
|
|
|
It is not very fun searching through many STart magazines looking for that
|
|
great David Small article on the floppy disc controller (STart magazine
|
|
Fall 1987, I think?). All those great programming articles in one place...
|
|
WOW! A CD-ROM would be perfect.
|
|
|
|
Just think of being able to look up all past reviews from all the
|
|
different magazines in one place. A hint ... CD-ROM would be nice! Trying
|
|
to remember which magazine which they built a hard drive in... you could
|
|
search for it in seconds on a CD-ROM. Just think - complete text files and
|
|
Degas pictures for the diagrams too.
|
|
|
|
Remember something David Small said at one of his shows? "I want my
|
|
MAC-ST!" How about a new one.
|
|
|
|
"I WANT MY ATARI CD!!!"
|
|
|
|
|
|
/*********************************************************************/
|
|
GLOSSARY OF TERMS:
|
|
|
|
|
|
ADPCM = Adaptive Differential Pulse Code Modulation (audio that
|
|
allows compression) and is used in CD-ROM/XA.
|
|
AES = Audio Engineering Society
|
|
AIIM = Association for Information and Image Management
|
|
ANSI = American National Standards Institute
|
|
(sets industrial standards for the USA)
|
|
ATARI = Manufacturer of the World's Greatest Computers!
|
|
CD = CD or CD-DA is digital audio CD that we all enjoy listening
|
|
to. (RED BOOK) CD stands for Compact Disc. Stereo 16-bit
|
|
sound sampled at 44.1KHz.
|
|
CD-BRIDGE = Is an extension to CD-ROM/XA and is what Photo CD uses.
|
|
This allows for Photo CD discs to be played on CD-I
|
|
players as well. It adds additional information at the
|
|
track level of CD-ROM/XA track.
|
|
CD-I = CD-Interactive similar to CD-ROM and supports sound,
|
|
full motion video as well as data introduced by
|
|
Philips Corp. (GREEN BOOK)
|
|
CD-ROM = Based on audio CDs and is a read only medium and holds about
|
|
680 megabytes of information. (YELLOW BOOK)
|
|
CD-ROM/XA = CD-ROM eXtended Architecture is needed for Photo CDs. Special
|
|
information is added at the track level to give additional
|
|
features. This is a joint Philips, Sony and Microsoft
|
|
specification that deals with interleaving audio with data.
|
|
CD-R = A recordable CD. See CD-WO.
|
|
CD-WO = The disc can be written to many times but not erased. Tracks
|
|
are on the disc but data is not present. Data can be added
|
|
later on. (ORANGE BOOK part 2)
|
|
CHROMA = Color attributes, such as shade, saturation and hue.
|
|
CLIENT = In very general terms a "front end". Receives services
|
|
from the server. See server.
|
|
DISC IMAGE = An exact represent of bits that will be put on the CD-ROM.
|
|
This should not be confused with a graphic "image."
|
|
DRIVER = A series of instructions that is used to reformat the data
|
|
from a particular peripheral device to something the
|
|
computer can use. A printer driver is a good example.
|
|
EDC/ECC = Error Detection Code and Error Correction Code.
|
|
GREEN BOOK = The document which describes both disc format and
|
|
hardware specifications for Philips' proprietary CD-I
|
|
product.
|
|
HIGH SIERRA = (HS) the 1986 CD-ROM standard was superceeded by ISO-9660.
|
|
ISDN = Integrated Services Digital Network - basically allows for
|
|
voice, data and video to be used at the same time. This
|
|
could be said to be a vehicle for a single service that
|
|
supports all forms of signal traffic on a single platform.
|
|
ISO = International Organization for Standardization
|
|
(70+ standard organizations in different countries are
|
|
involved)
|
|
ISO-9660 = This international standard specifies the filesystem on
|
|
CD-ROM discs. (ISO 9660, 1988)
|
|
LUMINANCE = Portions of composite video signal that control brightness.
|
|
MASTERING = The process of physically making a disc. The facility is
|
|
very similar to the clean room used in making computer
|
|
chips. A glass master is "cut" using a laser; one or more
|
|
negative nickel stampers are made; and those are used to
|
|
produce the many copies of the CD-ROM.
|
|
MO = Magnetic Optical drive is read/write (many times)
|
|
optical device. Also defined in the ORANGE book part I.
|
|
MULTI-SESSION = The ability to read more than one session on a disc.
|
|
Very important for Photo CD. (Orange Book Part 2)
|
|
NISO = National Information Standards Organization.
|
|
ORANGE BOOK = Describes Magnetic Optical Disks and CD-Write Once discs.
|
|
It also deals with Multi-Session as well.
|
|
PREMASTERING = The method to produce a CD-ROM before sending it to a
|
|
mastering facility. This usually includes making the
|
|
ISO-9660 filesystem, adding error checking and correcting
|
|
code and making an image and then transferring the disc
|
|
image to tape.
|
|
PHOTO CD = Kodak's standard for storing pictures on CD-ROM discs.
|
|
POSIX = Formal description of one form of operating system of which
|
|
UNIX is an example. Many parts of UNIX are POSIX compatible
|
|
but not all of UNIX. POSIX specifics specific functions
|
|
that are part of the standard.
|
|
RED BOOK = CD audio standard introduced by Philips and Sony
|
|
ROCK RIDGE = Based on the fictional town in the movie "Blazing Saddles"
|
|
is an extension to ISO-9660 that allows for all the
|
|
special features in the UNIX filesystem to be used. Discs
|
|
formatted with Rock Ridge extensions can still be read
|
|
with any ISO-9660 driver.
|
|
SCSI = Small Computer System Interface (ANSI X3.31, 1986) allows
|
|
up to 7 devices (printers, hard disks, scanners, optical
|
|
drives, CD-ROM drives, networking cards and more) to a single
|
|
interface card.
|
|
SERVER = In very general terms... "back end" (provides services to
|
|
a client). Usually thought of in a client-server type of
|
|
relationship. File server, printer server are good examples.
|
|
SGML = Standard Generalized Markup Language - provides a system
|
|
for tagging text structures with generic identifiers
|
|
which mark the category or class to which a piece of
|
|
text belongs. (ISO 8879, 1986)
|
|
SINGLE SESSION = The ability to read one TOC (table of contents) or one
|
|
session. All CD-ROM drives generally fall into this
|
|
category. Usually made in reference to Photo CD.
|
|
TOC = Table of Contents (similar to the table of contents found
|
|
in a book). All CDs have one or more of them. This also
|
|
gives information on where the tracks start.
|
|
UNIX = An operating system created by AT&T Bell Laboratories in 1971.
|
|
It has become a very popular operating system and it runs on
|
|
many different platforms. Unix International (UI) and
|
|
USL (Unix System Laboratories) are in charge of promoting
|
|
and enhancing the UNIX standard.
|
|
WORM = Write Once Read Many device. You can only write to one
|
|
area on the disc once but you can read it many, many times.
|
|
The data that has been written can never be overwritten.
|
|
YELLOW BOOK = CD-ROM standard like the red book also by Sony and Philips.
|
|
|
|
|
|
/********************************************************************/
|
|
CD-ROM Drive manufacturers (not a complete list)
|
|
|
|
|
|
Chinon America, Inc
|
|
615 Hawaii Avenue
|
|
Torrance, CA 90503
|
|
USA
|
|
(800)-441-0222
|
|
(310)-533-0274
|
|
|
|
Hitachi Home Electronics
|
|
401 West Artesia Blvd
|
|
Compton, CA 90220
|
|
USA
|
|
(800)-369-0422
|
|
(310)-537-3766
|
|
|
|
NEC Technologies
|
|
1255 Michael Drive
|
|
Wood Dale, IL 60191
|
|
USA
|
|
(800)-366-0476
|
|
(800)-FONE-NEC
|
|
(708)-860-9500
|
|
|
|
Panasonic Communications
|
|
Two Panasonic Way
|
|
Secaucus, NJ 07904
|
|
USA
|
|
(800)-742-8086
|
|
(201)-348-7000
|
|
|
|
Philips Consumer Electronics
|
|
1 Philips Drive
|
|
Knoxville, TN 37914
|
|
USA
|
|
(615) 475-8869
|
|
|
|
Pioneer Communications of America
|
|
600 E. Cresent Ave
|
|
Upper Saddle River, NJ 07458
|
|
USA
|
|
(800)-527-3766
|
|
(201)-348-7000
|
|
|
|
Sony Corp of America
|
|
655 River Oaks Pkwy
|
|
San Jose, CA 95134
|
|
USA
|
|
(800)-352-7669
|
|
(408)-432-0190
|
|
(408) 434-6644
|
|
|
|
Texel
|
|
1605 Wyatt Drive
|
|
Santa Clara, CA 95054
|
|
USA
|
|
(800)-886-3935
|
|
(408)-980-1838
|
|
|
|
Toshiba America Information Systems
|
|
9740 Irvine Blvd
|
|
Irvine CA 92718
|
|
USA
|
|
(800)-456-DISK
|
|
(714) 455-0407
|
|
(714)-538-3000
|
|
(714) 583-3129 (upgrade info)
|
|
|
|
|
|
/*********************************************************************/
|
|
Sources for the standards and general information:
|
|
|
|
|
|
Audio Engineering Society (AES)
|
|
60 East 42nd Street
|
|
New York, NY 10165-2520
|
|
USA
|
|
|
|
|
|
Association for Information and Image Management (AIIM)
|
|
1100 Wayne Avenue, Suite 1100
|
|
Silver Spring, MD 20910
|
|
USA
|
|
(301)-587-8202
|
|
|
|
A professional association dedicated to document and information
|
|
automation and imaging. Includes applications of micrographics, optical,
|
|
and computer technology and systems for the information professional.
|
|
|
|
|
|
American CD-I Association
|
|
11111 Santa Monica, Suite 750
|
|
Los Angeles, CA 90025
|
|
USA
|
|
(213)-444-6619
|
|
|
|
Green Book or CD-I information
|
|
|
|
|
|
American National Standards Institute
|
|
11 West 42nd Street
|
|
New York, NY 10036
|
|
USA
|
|
212-642-4900
|
|
|
|
ANSI specifications
|
|
|
|
|
|
CD-ROM Professional Magazine
|
|
462 Danbury Road
|
|
Wilton, CT 06897
|
|
(800)-248-8466
|
|
|
|
This is a very good magazine for anyone in the CD-ROM business.
|
|
|
|
|
|
COMPUSERVE
|
|
5000 Arlington Centre Blvd
|
|
Columbus, Ohio, 43220
|
|
USA
|
|
(800)-848-8990
|
|
(614)-457-8650
|
|
|
|
ATARIPRO forum: (GO ATARIPRO)
|
|
|
|
file(s): SCSI specifications I and II (working specifications and not the
|
|
official which are only available from ANSI, ISO or Global
|
|
Engineering Documents).
|
|
|
|
CD-ROM forum: (GO CD-ROM)
|
|
|
|
file(s): Complete Rock Ridge specification, High Sierra specification,
|
|
CD-ROMF.ZIP, CDFAQ.TXT (frequently asked questions about CD-ROM),
|
|
and many other files. The other files deal with steps necessary
|
|
to make your own CD-ROMs, retrieval engines, CD-ROM related
|
|
periodicals, vendors (that sell CD-ROM discs), manufacturers
|
|
and CD-ROM consultants.
|
|
|
|
DR DOBBS JOURNAL forum (GO DDJFORMUM)
|
|
|
|
file(s): The C source for the December 1992 issue which has an article on
|
|
the ISO-9660 CD-ROM filesystem.
|
|
|
|
PHOTO forum (GO PHOTOFORUM)
|
|
|
|
section (5): Dedicated to Kodak's Photo CD
|
|
|
|
|
|
Dr. Dobb's Journal
|
|
411 Borel Ave
|
|
San Mateo, CA 94402
|
|
USA
|
|
(800)-688-3987
|
|
(415)-358-9500
|
|
|
|
A magazine dedicated to programming. The December 1992 issue had an
|
|
article called "INSIDE THE ISO-9660 FILESYSTEM FORMAT." Future articles
|
|
will cover Rock Ridge, CD-I, and CD-ROM/XA.
|
|
|
|
|
|
Eastman Kodak Company
|
|
Information Center
|
|
343 State Street
|
|
Rochester, NY 14650
|
|
USA
|
|
(800)-242-2424 ext. 53 - for information of Kodak Photo CD products
|
|
and compatible CD-ROM drives
|
|
ext. 36 - Locations to get Photo CD discs made
|
|
|
|
Kodak services, imaging, Photo CD, Photo CD compatibility information
|
|
|
|
|
|
GLOBAL ENGINEERING DOCUMENTS:
|
|
2805 McGraw Ave
|
|
Irvine, CA 92714
|
|
USA
|
|
(800)-854-7179
|
|
(714)-261-1455
|
|
(714)-261-7892 (fax)
|
|
|
|
More than a million documents. ISO specs and index, ANSI specs and index,
|
|
Engineering specs, Government standards, Software Standards and much, much
|
|
more. What don't they have?
|
|
|
|
|
|
Interactive Multimedia Association
|
|
3 Church Circle, Suite 800
|
|
Annapolis MD 21401-1933
|
|
USA
|
|
(410)-626-1380
|
|
(410)-263-0590 (fax)
|
|
|
|
High level membership actively working on technical standards for
|
|
cross-platform compatibility of authoring and delivery systems.
|
|
|
|
|
|
National Information Standards Organization (NISO)
|
|
PO Box 1056
|
|
Bethesda, MD 20827
|
|
USA
|
|
(301) 975-2814
|
|
|
|
A volunteer organization which develops ideas for a standard and then
|
|
passes it to standard organization like ANSI and ISO.
|
|
|
|
|
|
Optical Publishing Association
|
|
PO BOX 21268
|
|
Columbus, OH, 43221
|
|
USA
|
|
(614)-422-8805
|
|
(614)-442-8815 (fax)
|
|
|
|
OPA is the Optical Publishing Association, a non-profit trade and
|
|
professional group directed at helping publishers and all other players
|
|
build a digital publishing market. They also publish materials, including
|
|
a newsletter "Digital Publishing Business," and one can contact via
|
|
COMPUSERVE Rich Bowers of the OPA ( CIS id = [71333,1114] ) for more
|
|
information.
|
|
|
|
|
|
Prentice Hall
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Englewood Cliffs, NJ 07632
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USA
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BOOK: SCSI: Understanding the Small Computer System Interface
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by John Lohmeyer (Standards Architect, NCR Corporation)
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Chairman X3T9.2 (scsi committee)
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Discussion of SCSI-1, and a little on SCSI-2 and SCSI-3.
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SCSI BBS ( operated by NCR corp )
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USA
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(719)-574-0424 (bbs)
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Source for SCSI information and working specifications not the complete
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specifications which must be bought from ANSI or GLOBAL ENGINEERING.
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This includes SCSI-1, SCSI-2, and Fast SCSI, Wide SCSI and SCSI-3.
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Tech Specialist
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2601 Iowa
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Lawrence, KS 66046
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USA
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(913)-841-1631
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The May 1991 of Tech Specialist had several articles on CD-ROM.
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a) "The ISO 9660 File System: A Reference Document"
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b) "Designing A CD-ROM Retrieval System"
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c) "Networking A CD-ROM drive"
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Tech Specialist is published by R&D Publications which also publishes the
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C USERS JOURNAL.
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Walnut Creek CD-ROM
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1547 Palos Verdes Mall, Suite 260
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Walnut Creek, CA 94596
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USA
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(800)-786-9907
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(510)-947-5996
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(510)-947-1644
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Pre-Mastering and Mastering Services, also sells usenet/internet archives
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on CD-ROM. They will make you a master CD-ROM for $200 and up. Both
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ISO-9660 and Rock Ridge formatting are supported.
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CD-ROMs (CICA, Simtel20, Source Code, X11r5/GNU, C User's Group CD-ROM,
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etc.)
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------------------------------------------------------------------------
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Microsoft MS-DOS CD-ROM Extensions 2.1
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The format of the directory record for High Sierra discs is:
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/* High Sierra directory entry structure */
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typedef struct hsg_dir_entry {
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uchar len_dr; /* length of this directory entry */
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uchar XAR_len; /* length of XAR in LBN's */
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ulong loc_extentI; /* LBN of data Intel format */
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ulong loc_extentM; /* LBN of data Molorola format */
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ulong data_lenI; /* length of file Intel format */
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ulong data_lenM; /* length of file Motorola format */
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uchar record_time[6];/* date and time */
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uchar file_flags_hsg;/* 8 flags */
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uchar reserved; /* reserved field */
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uchar il_size; /* interleave size */
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uchar il_skip; /* interleave skip factor */
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ushort VSSNI; /* volume set sequence num Intel */
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ushort VSSNM; /* volume set sequence num Motorola*/
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uchar len_fi; /* length of name */
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uchar file_id[...]; /* variable length name upto 32 chars */
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uchar padding; /* optional padding if file_id is odd length*/
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uchar sys_data[...] /* variable length system data */
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} hsg_dir_entry;
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The format of the directory record for ISO-9660 discs is:
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/* ISO-9660 directory entry structure */
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typedef struct iso_dir_entry {
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uchar len_dr; /* length of this directory entry */
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uchar XAR_len; /* length of XAR in LBN's */
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ulong loc_extentI; /* LBN of data Intel format */
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ulong loc_extentM; /* LBN of data Molorola format */
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ulong data_lenI; /* length of file Intel format */
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ulong data_lenM; /* length of file Motorola format */
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uchar record_time[7];/* date and time */
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uchar file_flags_iso;/* 8 flags */
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uchar il_size; /* interleave size */
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uchar il_skip; /* interleave skip factor */
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ushort VSSNI; /* volume set sequence num Intel */
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ushort VSSNM; /* volume set sequence num Motorola*/
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uchar len_fi; /* length of name */
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uchar file_id[...]; /* variable length name upto 32 chars */
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uchar padding; /* optional padding if file_id is odd length*/
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uchar sys_data[...] /* variable length system data */
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} iso_dir_entry;
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The difference between the two forms is the file flag byte moved to account
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for an additional byte of date and time used for a Greenwich mean time
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offset. See the May 28th draft of the High Sierra proposal or ISO-9660 for a
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more complete explanation of the fields. Note that the C structs above are
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not syntactically correct; C does not allow variable length arrays as struct
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elements.
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Choice of Filename Characters
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On the first Microsoft Test CD-ROM disc, the Codeview demo failed because
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certain filename characters that were legal on MS-DOS were not allowed
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according to the High Sierra file format. When the software looked for file
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'S1.@@@', it wasn't found because the character '@' is illegal for High
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Sierra filenames and during High Sierra premastering, the file was renamed
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'S1'.
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Valid High Sierra filename characters are the letters 'A' through 'Z', the
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digits '0' through '9', and the underscore character '_'. All other
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characters are invalid. Note that the letters 'a' through 'z' are not
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included so that High Sierra file names are not case sensitive. Under DOS,
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filenames are mapped to upper case before they are looked up so this is
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typically not a problem. When choosing file name characters, keep in mind
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the restrictions of the file structure format and the operating systems your
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media may be targeted towards.
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Depth of Path
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The High Sierra format allows for pathnames to be up to 8 levels deep. It's
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possible to create a path on MS-DOS that is deeper than that but you won't
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be able to transfer it to a CD-ROM.
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\one\two\three\four\five\six\seven\eight\file.txt /* Ok */
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\one\two\three\four\five\six\seven\eight\nine\file.txt /* Illegal */
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Length of Path
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The High Sierra format allows for the entire pathname to be a maximum of 255
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characters. Since MS-DOS imposes a limit far lower than this, this should
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not present a problem. The MS-DOS call to connect to a sub-directory is
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limited to a directory string of 64 characters. The length of path
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restriction is more a concern for Xenix/Unix than MS-DOS.
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Amusingly enough, the MS-DOS call to create a sub-directory allows a
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directory string greater than 64 characters which allows you to create sub-
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directories that you cannot connect to.
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Unfortunately, a CD-ROM may potentially contain a pathname that is much
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larger than 64 characters long. This is not a concern here but is discussed
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in a related memo - "MS-DOSifying your CD-ROM". As a rule, try to keep the
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length of your longest path less than 64 characters and you should be pretty
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safe.
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