121 lines
6.0 KiB
Plaintext
121 lines
6.0 KiB
Plaintext
MiniSport Laptop Hacker - Vol 15 7 July 1993
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Copyright (c) 1993 Brian Mork
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>>> ADMIN
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This month has been busy! I've been installing (definitely progressive
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tense English --these things seem to never end :) an Internet node and
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that has taken a lot of time. Watch the comp.sys.zenith and
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rec.radio.amateur.packet newsgroups for future issues of MLH if you're on
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Internet. Exposure on that net created a flood of feedback. The biggest
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feedback item? MiniSports fail by loosing their power supply. I'm still
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working on the project from last issue --restoring my busted power sup-
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ply.
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This issue is sent out with R95 on those nets that require it. R95 is a
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neat program that automatically splits and reassembles large files. Let
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me know if it works for you before I terminate the "trial run" and commit
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to using it long term. If you'd like a copy and you're Internet capable,
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I'll send you a UUENCODEd copy. If you're Amateur Packet only, I can
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copy stuff onto disk if you make it a no-cost option for me. I'll put a
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variety of other MLHacker related goodies on there, too.
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Flying for the Air Force is my primary job. They're sending me TDY to
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Saudi Arabia again, which will knock out all this fun stuff until mid-
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September. Look for Volume 16 at about that time.
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>>> RESOURCES
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I came across three articles you may be interested in. The first is
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"Real World Portability," in Oct 1989 REMark, written by Nathan Baker. It
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is a product review of the Minisport when it just came out on the market
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(you don't want to know the initial price!). In the same issue, William
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M. Adney writes "On the Leading Edge" which featured the Minisport as one
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step in ZDS's progression on the frontier of new system designs. The
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third article, "The Care and Feeding of MinisPorts," by Mary Ellen Shutz,
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appears in the July 1991 issue of REMark. It discusses power management,
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an expanded and more authoritative version of MLH Volume 11. After read-
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ing the third article, I notice an error on my part. Using SLOW mode in
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the SETUP is not the same as invoking SLOW mode via the FN-F3 keyboard
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sequence. The SETUP option actually chooses between 8 MHz and 4.77 MHz
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operation, but the keyboard sequence just inserts wait states to slow the
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system down. REMark is the official Zenith Data Systems magazine.
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>>> TECH HELP REQUESTED
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I have the PMP (Poor Man's Packet) running in the modem slot of my Minis-
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port, thanks to the help of a local ham (Ron, N7SXD). The receive works
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fine, but upon transmit, the software chokes. I'm convinced that on the
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Minisport, the algorithms coded in C just aren't fast enough. Has any-
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body out there rewritten critical sections in assembly?
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>>> DOUBLE YOUR SERIAL PORT COUNT
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This schematic came in via Internet. Thank you Peter (N9IYJ)! It con-
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nects into the internal modem header and converts it from a TTL port to a
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standard PC compatible serial port. Quoting Peter...
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"Following is an attempt at an ASCII schematic for a second serial port
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for the Minisport. The electrical part is pretty simple (the 14C88 and
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14C89 do all the work), the tricky part was the mechanical assembly. I
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built it on a small piece of perfboard, and carefully matched the 16 pin
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header so it slides right into the modem slot. Since the 8 pin jack was
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a lot bigger than the phone jack that is supposed to plug into the modem,
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I cut away part of the modem slot cover to provide access.
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Minisport RS-232 Connector
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Modem (See Note)
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Connector Numbers in parentheses
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(See MLHacker #8) are for DB-25 Connector
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+5V |1 --------------- |
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| | 14 |
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| ------------- |
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| 11| |13 |
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DCD |6 <-+----| 14C89 |------------| DSR (pin 6)
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| | | RS-232 | |
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DSR |16 <-| | Line | |
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| 8| Receiver |10 |
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RxD |7 <------| |------------| RxD (pin 3)
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| | | |
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| 3| |1 |
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CTS |14 <------| |------------| CTS (pin 5)
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| | | |
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| ------------- |
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| |7 |
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GND |4 --------------+------------------| GND (pin7)
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| v |
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+10V|2 -------------- |
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| | 14 |
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| ------------- |
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| 2| |3 |
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TxD |9 >------| |------------| TxD (pin 3)
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| | 14C88 | |
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| 4,5| RS-232 |6 |
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DTR |13 >------| Line |------------| DTR (pin 20)
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| | Driver | |
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| 13,12| |11 |
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RTS |15 >------| |------------| RTS (pin 4)
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| ------------- |
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| |1 |7 |
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-10V|3 ------------- | |
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GND |8 ----------------+ |
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Note: I terminated the RS-232 in an 8-pin modular connector, using
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a pinout to match an existing cable. Since the cable didn't have both
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DCD and DSR, I tied them together at the minisport side. There is another
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receiver available if you want to bring DCD out to pin 8 of the DB-25
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connector."
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73, Brian Mork (Opus-OVH) KA9SNF@wb7nnf.#spokn.wa.usa
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Internet BMORK@opus-ovh.spk.wa.us
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6006-B Eaker, Fairchild, WA 99011
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