112 lines
4.5 KiB
Plaintext
112 lines
4.5 KiB
Plaintext
list
|
|
|
|
List (Unformatted): AMDOS.INFO
|
|
|
|
This file must be called "AMDOS.INFO" on your computer.
|
|
|
|
AmDOS 3.5
|
|
Copyright 1985 Gary B. Little
|
|
|
|
AmDOS 3.5 (Amateur Disk Operating System version 3.5) is an
|
|
Apple II program for initializing 3.5-inch UniDisk disks in such
|
|
a way that they will boot the DOS 3.3 operating system and work
|
|
properly with it. To use it, first LOAD your Applesoft greeting
|
|
program into memory and then BRUN the program called AMDOS INIT.
|
|
After you press the space bar to clear the "user-supported
|
|
program" notice, enter the slot and drive number of the disk to
|
|
be formatted and then the name of the greeting program; once you
|
|
do this, insert the disk to be formatted and press "F" to start
|
|
the process. Formatting takes approximately one minute.
|
|
|
|
AmDOS logically divides a formatted 3.5-inch disk into two
|
|
discrete 400K volumes; there are 50 tracks per volume and 32
|
|
sectors per track. Use the ",D1" and ",D3" drive parameters (as
|
|
well as a slot parameter, if necessary) with your DOS 3.3
|
|
commands to select the first and second volumes of drive 1. Use
|
|
",D2" and ",D4" to select the first and second volumes of drive
|
|
2. For example, to catalog the second volume on drive 1, use the
|
|
command "CATALOG,D3". As with standard DOS 3.3, if you don't
|
|
specify a slot or drive parameter, the most recently specified
|
|
value is implicitly used.
|
|
|
|
Compatability
|
|
|
|
With AmDOS installed, the INIT command is disabled. If you need
|
|
to initialize a 5.25-inch floppy disk, you will first have to
|
|
boot a disk that contains a standard copy of DOS 3.3. To re-
|
|
install AmDOS after you've loaded standard DOS 3.3, boot from a
|
|
previously formatted 3.5-inch disk.
|
|
|
|
AmDOS makes use of two data areas in the high end of memory:
|
|
$BD12-$BD14 and $BEAF-$BFA7. These areas must not be used by any
|
|
DOS 3.3 "patches" you might install. AmDOS also uses a 512-byte
|
|
I/O buffer at $9AF9-$9CF8; the standard DOS 3.3 file buffers are
|
|
installed just below this area. AmDOS sets MAXFILES = 2 (two
|
|
file buffers) when it boots up; this means that HIMEM (the top
|
|
of memory pointer) initially contains $9653. The DOS 3.3 default
|
|
of MAXFILES = 3 is not used because that would result in a HIMEM
|
|
of $9400, instead of the usual $9600, and any program that used
|
|
the area from $9400 and $95FF for data storage would not work
|
|
properly because the file buffer area would be overwritten. Such
|
|
programs erroneously assume that HIMEM is always $9600.
|
|
|
|
If you want to run a program that expects three file buffers to
|
|
be active (there are not many programs like this), enter the
|
|
DOS 3.3 "MAXFILES 3" command before running it.
|
|
|
|
You can use a slightly-modified version of the FID utility
|
|
program on the DOS 3.3 system master disk to transfer files to
|
|
and from AmDOS-formatted 3.5-inch disks. Here are the steps to
|
|
follow to make the modifications to a copy of FID:
|
|
|
|
]UNLOCK FID
|
|
]BLOAD FID
|
|
]CALL -151
|
|
*0973:B5
|
|
*09BF:B5
|
|
*11ED:4C 89 16
|
|
*1414:B1
|
|
*1689:8D 31 19 B9 8B 19 8D 32 19
|
|
*1692:B9 8C 19 8D 33 19 0D 32 19
|
|
*169B:0D 31 19 4C F2 11
|
|
*3D0G
|
|
]BSAVE FID,A2051,L4686
|
|
|
|
The modified FID will still work properly with standard DOS 3.3
|
|
and with 5.25-inch floppy disks.
|
|
|
|
Memory Map
|
|
|
|
Here is a memory map showing the arrangement of buffers below
|
|
the main AmDOS code and data area beginning at $9D00:
|
|
|
|
^ ^
|
|
| AmDOS (DOS 3.3) |
|
|
| code and data area |
|
|
-------------------------- <--- $9D00
|
|
| [unused] |
|
|
-------------------------- <--- $9CF9
|
|
| AmDOS 512-byte buffer |
|
|
-------------------------- <--- $9AF9
|
|
| |
|
|
| File buffer #1 |
|
|
| |
|
|
-------------------------- <--- $98A6
|
|
| |
|
|
| File buffer #2 |
|
|
default | |
|
|
HIMEM ---> -------------------------- <--- $9653
|
|
| |
|
|
| File buffer #3 |
|
|
| (only if MAXFILES = 3) |
|
|
-------------------------- <--- $9400
|
|
|
|
|
|
AmDOS 3.5 is a user-supported program. Try it for 30 days and if
|
|
you find it useful, send $15 (U.S.A. funds) or $20 (Canadian
|
|
funds) to Gary B. Little, #210 - 131 Water Street, Vancouver,
|
|
British Columbia, Canada, V6B 4M3 (Telephone: (604) 681-3371).
|
|
Otherwise, pass your copies along to others or erase them.
|
|
|
|
|
|
ACTION> (Next, Down, Xm, List) |