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README update

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This commit is contained in:
Jeff Parsons 2015-05-01 09:40:12 -07:00 • committed by jeffpar
commit 857db340c7
4 changed files with 11 additions and 12 deletions
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2
blog/2015/04/16/README.md
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@ -8,7 +8,7 @@ but booting from a floppy works.
While working through issues with this ROM BIOS, I created some lightly-annotated
[source code](/devices/pc/bios/compaq/deskpro386/1988-01-28.nasm) that can be re-assembled
with [NASM](http://www.nasm.us/). The initial process of creating the source code is
explained [here](/devices/pc/bios/compaq/deskpro386/#producing-rom-source-code).
explained [here](/devices/pc/bios/compaq/deskpro386/#recreating-rom-source-code).
At the top of the source code, I explain a few important details about ROM addresses that
are worth recapping here:

17
devices/pc/bios/compaq/deskpro386/README.md
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@ -48,7 +48,7 @@ from the two 16Kb BIN files provided by [Al Kossow](http://www.vintage-computer.
filedump --file=private/109592-005.U11.bin --merge=private/109591-005.U13.bin --output=private/1989-04-14.rom --format=rom
filedump --file=private/1989-04-14.rom --output=1989-04-14.json
Reading the ROMs
Dumping the ROMs
---
The *.hex* files for the 1988-01-28 DeskPro ROM were produced by running [eeprom_read](http://github.com/phooky/PROM/blob/master/tools/eeprom_read/eeprom_read.pde)
on a [chipKIT Uno32](http://www.digilentinc.com/Products/Detail.cfm?NavPath=2,892,893&Prod=CHIPKIT-UNO32) Arduino-compatible
@ -67,7 +67,7 @@ while the /PGM should be connected to INPUT HIGH VOLTAGE. So I wired pin 27 (/P
worked perfectly. The NYC Resistor article implied that every *active low* pin should be connected to GND, but apparently
there are exceptions to that general rule.
Producing ROM Source Code
Recreating ROM Source Code
---
In the current directory, an original ROM can be regenerated from the JSON-encoded file:
@ -87,19 +87,18 @@ Next, the PCjs [TextOut](/modules/textout/lib/) command, with the *--nasm* optio
node ../../../../../../modules/textout/bin/textout --file=1988-01-28.nasm --nasm > temp.nasm
mv temp.nasm 1988-01-28.nasm
The result, [1988-01-28.nasm](1988-01-28/1988-01-28.nasm), after a small amount of manual cleanup, can now be successfully reassembled:
The result, [1988-01-28.nasm](1988-01-28/1988-01-28.nasm), after a small amount of manual cleanup, can now be
successfully reassembled:
nasm -f bin 1988-01-28.nasm -l 1988-01-28.lst -o 1988-01-28.rom
However, it does NOT produce a binary identical to the original ROM, in part because of instruction ambiguities (ie,
instructions that can be assembled multiple ways).
It's possible the reassembled ROM may still work, but more research is required.
instructions that can be assembled multiple ways). It's possible the reassembled ROM may still work, but more research
is required.
One interesting section of the Compaq DeskPro ROM is this string at offset 0xE002:
db 'AUTHORS CAB93GLB93RWS93DJC93NPB(C)Copyright COMPAQ Computer Corporation 1982,83,84,85,86'
Anyone care to take a stab at what `CAB93GLB93RWS93DJC93NPB` means? Is it the initials of 5 people
(CAB, GLB, RWS, DJC, NPB), separated by "93"? I've already confirmed that
[Google](https://www.google.com/?gws_rd=ssl#q=CAB93GLB93RWS93DJC93NPB) doesn't know.
which appears to list the initials of 5 authors: **CAB**, **GLB**, **RWS**, **DJC**, and **NPB**. The meaning of the
"93" sequences is unknown; they may have simply been a form of obfuscation.

2
devices/pc/video/compaq/vga/README.md
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@ -41,7 +41,7 @@ a way of getting the sharpest and fastest graphics without abandoning your commi
As such, this board is in perfect accord with the Compaq philosophy, and it may be the best way available
for mating a VGA-style monitor and VGA graphics to your AT.
A copy of the board's [VGA ROM BIOS](109360-001/1988-05-18.json) was created by [dumping](/devices/pc/bios/compaq/deskpro386/#reading-the-roms)
A copy of the board's [VGA ROM BIOS](109360-001/1988-05-18.json) was created by [dumping](/devices/pc/bios/compaq/deskpro386/#dumping-the-roms)
the contents of each EPROM chip to a *.hex* file, and then merging the *.hex* files with the following
[FileDump](/modules/filedump/) command:

2
devices/pc/video/paradise/vga/README.md
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@ -4,7 +4,7 @@ This Paradise VGA board was manufactured in 1988 and sold by Western Digital Cor
![Paradise VGA Board](/devices/pc/video/paradise/vga/static/Paradise_VGA_1988-640.jpg "link:/devices/pc/video/paradise/vga/static/Paradise_VGA_1988.jpg")
A copy of the board's [ROM BIOS](1988-05-23.json) was created by [dumping](/devices/pc/bios/compaq/deskpro386/#reading-the-roms)
A copy of the board's [ROM BIOS](1988-05-23.json) was created by [dumping](/devices/pc/bios/compaq/deskpro386/#dumping-the-roms)
the contents of each of the board's two M27128AZB PROMs to a *.hex* file, and then merging the *.hex* files with the following
[FileDump](/modules/filedump/) command: