IBM Personal System/2 Model 55 SX

Machine type 8555-031
Serial 55-F6621
Manufacturer IBM Corp., United Kingdom
Date October 1989

Physical description

Type Desktop
Dimensions (HxWxD) 102 x 406 x 397 mm
Weight 8.65 Kg
Drive bays 2 x 3.5" half-height, both accessible
Power supply 90 W, 110-220VAC (DATE 9216) REPLACEMENT

Main board

Manufacturer IBM (chips 8943 or earlier), planar id FBFF
BIOS IBM, Nov. 2, 1988 (24/10/89 sticker)
Processor Intel 80386SX-16MHz (32-bit), PQFP
Coprocessor Socket for optional i80387SX Math coprocessor
Memory 2 sockets for 85ns 72-pin SIMMs (PS/2 type), parity checked (*)
Max on system board 8 Mb (2 x 4 Mb)
Max. using adapter cards 16 Mb (about 15,5 Mb usable)
Bus Micro channel (MCA) 16-bit
Expansion slots 3 (16-bit, one w. video ext.)
Video Integrated 16-bit VGA display adapter (256 Kb, max. 320x200, 256 colours or 640x480, 16 colours)
Interface HDD (2 units type ST-506), FDD (2 units)
Ports PS/2 keyboard, PS/2 mouse, serial (UART 16550), parallel, VGA


Installed RAM 2 x 4 Mb 80ns SIMMs (one has 9051)


Diskette drive 1.44 Mb, 3.5" slim (Ye-Data YD-701, 89-32)
Hard disk Model WDL-330R (30 Mb), 3.5" slim (8943 on connect.)


Acquisition Mid-2000, gift
Condition Very good
Installed O.S. IBM PC-DOS 5.0 (Italian)
Repairs/modifications Replaced 2 Mb memory SIMM with 2 x 4 Mb SIMMs
Current status All hw working
Spare parts Almost everything, incl. drives, planar, etc.


(*) 80ns SIMMs OK, does not accept 70ns SIMMs.


Back to Systems Listing
Back to PCs Main Page
Back to Home page

This page was first published on the web on Nov. 11, 2001
Last revised Oct. 22, 2004