First post, by remi020878
I recently got 2 old new stock GMB-486SG
High Performance 486 VLB Motherboards. Both are Rev. 2. As I am trying to build awesome 486 machines with them, one seems to have a "ghost" and my knowledge is just not good enough to tackle this problem. Here are the symptoms:
- CMOS date and time is working except the year always returns 2094 without any regard as to what I set it to be or what kind of CMOS battery is used,
- during DOS install, I get "can't read file xxxx" error followed by "can't write file xxxx". The process allows me to skip those files and continue, but it does stop at some point and the system just hangs up
- after changing cache size from 256k to 128k the DOS installas correctly but only 8MB of ram is recognized. If I double that the system hangs up
- tried running Raptor and Duke3D and both games crashed after about a minute of playing
System configuration is as follows
486DX2 66Mhz
8MB RAM 60ns non parity
Winbond multi I/O controller on 16 bit ISA
Cirrus Logic 5426 1MB on VLB bus
10.1 GB Matrox 5400 rpm HDD recognized as 2.1 GB by BIOS
I tried different CMOS batteries, all brand new, including external without any change in behavior. There is physically 256k of L2 cache and 32kx8 tag ram chip.
Can't figure out where the problem is. I have checked and rechecked jumper settings for the CPU and cache. Any ideas?? Thank you
