PCChips M921 (486)
Also known as: Unknown 4D IP UMC AIO Unknown TD 4IP UMC AIO CONCORD OFFICE AUTOMATION INDUSTRIAL (HK),, LTD. COA-921 Sunnylab SYL-8885
Form factor
Baby-AT (max 220 x 330mm)
PSU connector
AT-Style (P8-P9)
Chipset
Chipset parts
UMC UM8881 UMC UM8886
Dimensions
254 mm x 218 mm
CPU socket
Socket 3 (PGA237)
CPU platforms
486486 (DX4)
Supported FSB speeds
25MHz, 33MHz, 40MHz, 50MHz
Cache
128 KB , 256 KB , 512 KB
Supported RAM size
256 MB
Supported RAM types
72-pin FPM, 72-pin EDO
I/O ports
1x 
Floppy interface
2x 
IDE interface
1x 
Parallel
2x 
Serial
Expansion slots
3x 
32-bit PCI
4x 
16-bit ISA

Known issues:

  • Fake cache.

    The cache mounted on the motherboard may be fake. Soldered DIP-chips "WRITE-BACK" markings and traces that go nowhere are often hints that the cache is fake. Soldered DIP chips can usually be removed and replaced by real cache chips on sockets to get functional cache.

Last updated 2022-11-28T20:05:16Z
drv Drivers: 2 entries
Language
Media type
OS Compatibility
Name
Version
English
1x 3.5" HD Floppy Disk
win3.1x Windows 3.1 win95 Windows 95 msdos MS-DOS 5.0 ? os2 3.x OS/2 Warp 3.0 ?
English
1x Archive
msdos MS-DOS 6.22 win3.1x Windows 3.11 ? win95 Windows 95 winnt3.5x Windows NT 3.51 os2 2.x OS/2 2.0 ?
BIOS images: 3 files
Manuf.
POST String
Note
Core Ver.
BIOS Ver.
AMI
41-P000-001437-00101111-101094-486AVIP
101094
AMI
41-P400-001437-00101111-101094-486AVIP
101094
Award
04/01/96-UMC-881E/886B-2A4X5000C-00
Sunnylab
4.51PG
doc Documentation: 2 entries
Model
Speed
FSB
Voltages
L1 Cache
L2 Cache
L3 Cache
Core
Process
TDP
AMD Am486 DX-40
40MHz
40MHz
5V
8KB
-
-
-
-
-
AMD Am486 DX4-120
120MHz
40MHz
3.3V
8KB
-
-
-
500nm
3W
AMD Am5x86-P75
133MHz
33MHz
3.45V
16KB
-
-
-
350nm
3W
AMD Am486 DX4-100
100MHz
33MHz
3.3V
8KB
-
-
-
500nm
2W
Cyrix Cx486 DX-50
50MHz
50MHz
5V
8KB
-
-
M6
-
-
Cyrix Cx486 DX2-80
80MHz
40MHz
5V
8KB
-
-
M7
-
-
Cyrix Cx486 DX2-66
66MHz
33MHz
5V
8KB
-
-
M7
-
-
Cyrix Cx486 DX-33
33MHz
33MHz
5V
8KB
-
-
M6
-
-
Cyrix Cx486 DX2-50
50MHz
25MHz
5V
8KB
-
-
M7
-
-
Cyrix 5x86-120
120MHz
40MHz
3.45V
16KB
-
-
M1sc
650nm
3W
Cyrix Cx486 DX2-v80
80MHz
40MHz
3.45V
8KB
-
-
M7
-
-
Cyrix 5x86-80
80MHz
40MHz
3.45V
16KB
-
-
M1sc
650nm
3W
Cyrix 5x86-133
133MHz
33MHz
3.45V
16KB
-
-
M1sc
650nm
3W
Cyrix Cx486 DX4 100
100MHz
33MHz
3.45V
8KB
-
-
M9
-
-
Cyrix 5x86-100
100MHz
33MHz
3.45V
16KB
-
-
M1sc
650nm
3W
Cyrix Cx486 DX2-v66
66MHz
33MHz
3.45V
8KB
-
-
M7
-
-
Cyrix Cx486 DX-v33
33MHz
33MHz
3.3V
8KB
-
-
M6
-
-
Cyrix Cx486 DX4 100
75MHz
25MHz
3.45V
8KB
-
-
M9
-
-
Cyrix Cx486 DX2-v50
50MHz
25MHz
3.45V
8KB
-
-
M7
-
-
Intel i486 DX 50
50MHz
50MHz
5V
8KB
-
-
P4
1000nm
-
Intel i486 DX2 66
66MHz
33MHz
5V
8KB
-
-
P24
800nm
5W
Intel i486 DX2 66 (WB)
66MHz
33MHz
5V
8KB
-
-
P24D
800nm
-
Intel i486 DX 33
33MHz
33MHz
5V
8KB
-
-
P4
1000nm
-
Intel i486 DX2 50
50MHz
25MHz
5V
8KB
-
-
P24
800nm
-
Intel i486 DX2 50 (WB)
50MHz
25MHz
5V
8KB
-
-
P24D
800nm
-
Intel i486 DX 25
25MHz
25MHz
5V
8KB
-
-
P4
1000nm
-
Intel i486 DX4 100
100MHz
33MHz
3.3V
16KB
-
-
P24C
600nm
-
Intel i486 DX4 75
75MHz
25MHz
3.3V
16KB
-
-
P24C
600nm
-
No NPUs listed.

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