Compaq DeskPro 386 ROMs
---
The oldest Compaq DeskPro 386 ROM I have is a Rev J.4 ROM from a "Version 2" motherboard designed
in 1987 and released in 1988.

![Compaq DeskPro 386 System Board Version 2](/pubs/pc/reference/compaq/static/images/Compaq_DeskPro_386-16_System_Board_V2-640.jpg "link:/pubs/pc/reference/compaq/static/images/Compaq_DeskPro_386-16_System_Board_V2.jpg")

Thanks to folks on the [Vintage Computer](http://www.vintage-computer.com/) forums, I also have a Rev N.1 ROM from 1989.

However, I'm still on the lookout for any "Version 1" motherboards from 1986, so that I can obtain dumps of Compaq's
ROMs for their earliest 80386-based systems.

### System ROM Locations on COMPAQ DESKPRO 386 System Board Version 2 (Assembly No. 000558-001)

	U13 (EVEN)
	U15 (ODD)

### System ROM Revisions

	Rev  Even ROM #  Odd ROM #   Size  Date
	---  ----------  ----------  ----  ----
	E    108285-001  108284-001
	F    108328-001  108327-001
	G    108328-002  108327-002
	H.8  113270-008  113269-008
	J.4  109592-001  109591-001  32Kb  1988-01-28
	K.2  109592-003  109591-003
	M.1  109592-004  109591-004
	N.1  109592-005  109591-005  32Kb  1989-04-14	

[1988-01-28.json]() was created with the following [FileDump](/modules/filedump/) command:

	filedump --file=109592-001.hex --merge=109591-001.hex --output=1988-01-28.json

For a more human-readable dump, use this command:

	filedump --file=109592-001.hex --merge=109591-001.hex --comments

And for those who prefer a binary file, the FileDump API can be used to recreate binary data from JSON data:

> [http://www.pcjs.org/api/v1/dump?file=http://www.pcjs.org/devices/pc/bios/compaq/deskpro386/1988-01-28.json&format=rom](http://www.pcjs.org/api/v1/dump?file=http://www.pcjs.org/devices/pc/bios/compaq/deskpro386/1988-01-28.json&format=rom)

Similarly, [1989-04-14.json]() was generated by first creating [1989-04-14.rom](http://www.pcjs.org/api/v1/dump?file=http://www.pcjs.org/devices/pc/bios/compaq/deskpro386/1989-04-14.json&format=rom)
from the two 16Kb BIN files provided by [Al Kossow](http://www.vintage-computer.com/vcforum/member.php?2256-Al-Kossow):

	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

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
prototyping board, and capturing the serial port output on my MacBook Pro -- as outlined in
"[Stick a Straw in Its Brain and Suck: How to Read a ROM](http://www.nycresistor.com/2012/07/07/stick-a-straw-in-its-brain-and-suck-how-to-read-a-rom/)"
by [NYC Resistor](http://www.nycresistor.com/) contributor [phooky](http://www.nycresistor.com/author/phooky/).

The DeskPro 386 ROMs were P27128A-2 chips, so I wired my Uno32 based on this [27128A](/pubs/pc/datasheets/static/27128A.pdf)
datasheet -- the closest match I could find online.

![Compaq DeskPro 386 System ROM Version 2](/pubs/pc/reference/compaq/static/images/Compaq_DeskPro_386-16_System_ROM_V2_Breadboard-640.jpg "link:/pubs/pc/reference/compaq/static/images/Compaq_DeskPro_386-16_System_ROM_V2_Breadboard.jpg")

On my first dump attempt, every ROM address returned 0xFF.  After looking at the 27128A datasheet more closely, I noticed
the DEVICE OPERATION table indicated that, for a READ operation, /CE and /OE pins should be connected to INPUT LOW VOLTAGE,
while the /PGM should be connected to INPUT HIGH VOLTAGE.  So I wired pin 27 (/PGM) to +5V instead of GND, and the dump
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 Source Code with NDISASM
---
From the current directory, I ran:

	ndisasm -o0x8000 private/1988-01-28.rom > 1988-01-28.nasm

Then I massaged the output with a regex:

	^([0-9A-F]+)\s+([0-9A-F]+)\s+(o32 |a32 |)([^\s]*) *(.*)$  -->  \t$3$4\t$5\t\t\t; $1  $2

Then I ran custom TextOut command to clean up the code:

	node ~/Sites/pcjs/modules/textout/bin/textout --file=1988-01-28.nasm --nasm > t.nasm
	mv t.nasm 1988-01-28.nasm

The result: [1988-01-28.nasm](1988-01-28.nasm).  Now it needs a human touch.