IBM Enhanced Personal System/2 Model 90 XP 486

Type 9590-ALA
Serial 55-0R3B9
Manufacturer IBM United Kingdom Ltd.
FCC ID AN08590B25
Date May 1993

Physical description

Type Desktop
Dimensions (HxWxD) 140 x 440 x 430 mm
Weight 11.4 Kg
Drive bays 3 x 3.5" half-height, 1 x 5.25" half-height (all accessible)
Power supply 194 W, 110-220VAC manual voltage switch (9303)

Main board

Chipset/Manufacturer IBM (planar id FF6F)
Bus Micro Channel (MCA) 32-bit
Expansion slots 4 x 32-bit (1 w. video ext., 2 available), one 64-bit for processor complex (proprietary), two 64-bit for memory cards (proprietary)
Interface FDD (2 units)
Video Integrated 16-bit XGA display adapter (1024x768, 16 colours; 640x480, 256 colours)
Ports PS/2 keyboard, PS/2 mouse, 2 buffered serial (UART 16550A), parallel, XGA


Type Type-2 complex (*)
BIOS IBM, Nov. 2, 1992 (sticker on BIOS chip 02/03/93)
Processor Intel 80486DX2-50 MHz (32-bit) PGA
Coprocessor integraded on 486DX
Ext. Cache N/a
Max Memory 64 Mb (8 x 8 Mb) (*)
Memory 2 memory riser cards (9302) - each card features 4 sockets for 70ns 72-pin SIMMs, parity checked (PS/2 proprietary) (**)
Installed RAM 64 Mb 70ns on riser cards (4 x 8 Mb SIMMs type 71F7011, 4 x 8 Mb type 78G9177, und.)
Controller IBM 32-bit PS/2 bus master SCSI adapter/A w. 512 Kb cache (id 8EFF) (sticker 08/02/93, cables WK 09-93)
Video IBM 32-bit XGA-2 adapter (id 8FDA) (sticker 22/01/93)


Diskette drive 2.88 Mb, 3.5" half-height (Mitsubishi MF356D dated MAY 1993)
Hard disk Model WDS-3200 (200 Mb), 3.5" slim size, SCSI
2nd Hard disk Model WDS-3200 (200 Mb), 3.5" slim size, SCSI ADDITION


Acquisition Summer 98, paid a few $ (together w. other appliances, incl. two other 9590-ALA which had been demolished)
Condition Very good, setup needed
Installed O.S. IBM OS/2 2.1 (Italian), hardly booting
Repairs/modifications Removed token-ring adapter, added second hard disk and six 8 Mb memory SIMMs (it had 16 Mb only)
Current status All hw working
Current O.S. IBM PC-DOS 5.0, MS Windows for Workgroup 3.11 (Italian)
Spare parts Almost everything, incl. drives, planar, etc.


(*) Existing processor complex can be changed with a newer one (Type-3 or 4, CPUs up to Pentium-90, supporting up to 256 Mb of RAM).

(**) Slower 80ns SIMMs can be used instead. Using a Type-2 processor complex SIMMs need not to be installed in pairs.


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This page was first published on the web on Nov. 11, 2001
Last revised May 24, 2004