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Compaq Portable III

Computers in Collection

Compaq Portable III, serial …,

Obtained from Sean@CCC, 2021/04/06.

Hard drive is a “type 2”, as labeled on display bezel.

In a fit of idiocy, I tried cleaning the display cover plastic with acetone, and crazed it but good. No amount of Novus polishing compound was helping. I eventually went at it with a red ScotchBrite, and even then wasn’t making much progress. It’s utterly destroyed. So I will need to make a replacement.

Display has vertical lines that seem to worsen during use (thermal behavior?).


  • Remove CMOS battery! Hasn’t visibly leaked yet, but why wait?!

  • Rear cover screws/washers:
    • 4 x 6-32 partially (19.8mm or ~3/4”) threaded, Torx T-15 drive, 5.7mm dia and 3.6mm height head, 98.3mm/3-7/8” shaft length. McMaster has some that might be suitable, but not for $15.98 each!
    • 2 x … much shorter machine screw …
  • Display bezel plastic: 293.5mm x 179.5mm, 1.6mm or 0.061” or 1/16” thick.


Compaq Portable III, serial 4916HL2H0055,

Obtained from Sean@CCC, 2021/10/03.

Missing drives and drive cage.

Remarkably, the keyboard cable is not cracking and crumbling!

Powers on, begins to boot, but then stops with a “102 SYSTEM BOARD FAILURE” if the RTC IC is not installed. I procured a Dallas/Maxim DS12887+ from Digi-Key (DS12887+-ND) and the problem was resolved.

I washed the display cover plastic very gently, using only Windex and my fingers to rub the dirt off, then a rinse in hot water. And still, I managed to wear off spots of the matte finish. *sigh*

Borrowed the rear case screws, drives, drive cage, drive face plate (cracked), a longer drive power cable, and keyboard hole cover from the other machine. The hard drive reports errors in diagnostics, but seems to work OK, though there’s very little data on the drive.

RAM expansion was tested with the USER DIAGNOSTICS floppy, and only the Toshiba RAM tested good. The TI RAM was removed and the system board reconfigured for only 2MB of extended RAM.


  • Power supply fan is noisy AF.
  • Drive face plate plastic is cracked.
  • Display cover plastic is mildly blemished.
  • Hard drive is not happy, at least according to the user diagnostics.
  • CMOS isn’t retained for long?
  • Four empty SIMM slots on RAM expansion board.
  • No system board shielding to speak of.



Missing keyboard cord-hole plug, screws for back exterior panel, panels for drive bay, drive bay removable cage.

Attribute Value
Name Compaq Portable III
Manufacturer Compaq
Model 2660
Serial 4916HL2H0055
Manufacture Date “JAN 25 1989” stamped in red, inside
Assembled In U.S.A.
Source Sean@CCC, 2021/10/03

Logic Board

Board variant does not have onboard RTC battery and associated circuitry.

Missing real time clock IC in U77.

E17 jumpers were bent out of shape.

Some shielding pieces are missing?

Two SIMMs installed.

ROM Revision Identifier, Version 1.02  
Machine type 80286
System ROM Revision: R.2
Family: P
Keyboard controller ROM Revision: E
Attribute Value
Name Compaq Portable III logic board
Manufacturer Compaq
Solder Mask bright green
Assembled In Singapore
Markings Component side: “REV. AF/AH-BW” “709-003”
Solder side: “*2TS3AOZJ%*” “8909” “000711-001 REV J” “COMPAQ COMPUTER CORP.” “COPYRIGHT 1987” “MADE IN TAIWAN”
RAM SIMMs J005: 9 x OKI JAPAN M41256A 912222 102
J006: 9 x OKI JAPAN M41256A 913009 102
ROMs U72: “109737-002”, U89: “109738-002”, and two empty sockets (U73, U90)
Other Socketed ICs AMD N80L286-12/S H 912KVKJ (m) (c) INTEL 1982
Intel D80287-8 L7070053 (m) (c) I ‘83 ‘84
Intel 106436-001 L9030753 2116 (c) COMPAQ ‘87 (m) (c) INTEL ‘81<br /
Source Sean@CCC, 2021/10/03

Memory Expansion Board

Attribute Value
Name Compaq Portable III memory expansion board
Manufacturer Compaq
Solder Mask clear
Made In U.S.A.
Markings Component side: “ASSY 000718-____” “REV ____” “MEMORY EXPANSION DIA 000719” “(c) 1987,1989 Compaq”
Solder side: “BOARD 000720-001” “*29042*” “12-89 3246-5” “REV. H” “*HB33DOKOP*”
RAM SIMMs J206: “P10-04B556200 REV.B” “9416”(?), 2 x “TI -70 TMS44400DJ TBP 4063 80”, 1 x “BP41C1000A-6” (label obscured)
J205: “P10-04B556200 REV.B” “9416”(?), 2 x “TI -70 TMS44400DJ TBP 4063 80”, 1 x “BP41C1000A-6” (label obscured)
J204: “P10-04B556200 REV.B” “9416”(?), 2 x “TI -70 TMS44400DJ TBP 4063 80”, 1 x “BP41C1000A-6” (label obscured)
J203: “P10-04B556200 REV.B” “9416”(?), 2 x “TI -70 TMS44400DJ TBP 4063 80”, 1 x “BP41C1000A-6” (label obscured)
J202: “TOYOCOM” “JAPAN” “TH3C10009E-T10” “38-88”, 9 x Toshiba “JAPAN 8833HCK TC511000AJ-10”
J201: “TOYOCOM” “JAPAN” “TH3C10009E-T10” “38-88”, 9 x Toshiba “JAPAN 8834HCK TC511000AJ-10”
Source Sean@CCC, 2021/10/03

Video Board

Shield tabs are not symmetrical – one tab missing, presumably to not block the P119 external video connector?

Attribute Value
Name Compaq Portable III video board?
Manufacturer Compaq
Solder Mask clear
Made In Japan
Markings Component side: “ASSY. 000932-001 S/N ____” “SCH 000933” “M1135-001”
Solder side: “(c) 1987 Compaq” “*49044*” “REV J” “*9BT36OQKH*” “TP TPB-J.VO” “8905” “BOARD NO. 000934-001 AW REV E FAB REV F”
Source Sean@CCC, 2021/10/03

Power Supply Board

Attribute Value
Name Compaq Portable III power supply
Manufacturer Compaq
Solder Mask green
Made In U.S.A.
Fuse F1: 5A 250V, solder tail
Markings Component side: “(c)1987 Compaq” “P III B” “BOARD NO. 000733” “A/W REV K FAB REV L” “DIA. 000732” “ASSY. NO. _____ 000731 REV. ____ “
Solder side: “*3S43AO18T*”
Source Sean@CCC, 2021/10/03