First post, by trowa
Hello, I have a 66Mhz Intel 486 system in my collection with a quirk or two I'm trying to sort out.
The motherboard appears to be an Abit AH4 based on this manual and the bios string (though the website incorrectly lists it as an Award, its really an AMIbios, cute little GUI and mouse support)
http://stason.org/TULARC/pc/motherboards/A/AB … ON-486-AH4.html
It had that lovely little Varta NiCD battery leaking out so I did cut it off, clean off the board and wire up a CR2032 to the External Battery pins conveniently placed nearby.
I upgraded it to 128MB of 8M x 36 FPM Parity memory, it is all recognized at POST but when I tried to run memtest (only version 3.5 on regular memtest not memtest+ would load) it only found 65MB, I have windows NT 4.0 installed and it also only recognizes 65MB (yes 65 not 64).
Not sure if there is some strange bios setting that may be causing detection issues, its also pretty much a certainty that this bios is not flashable.
The system also has 256KB of L2 on the board and I found UM61512AK-15 64K X 8 BIT on ebay (I am quite aware it could very well be knockoff or something) in order to bump it to 512KB. The chips aren't going to arrive for a little while but I was wondering if I should leave the current 20ns tag ram in which is 32x8 and the biggest size needed according to the manual, or if I should put one of the new chips in there too even though it is bigger than the manual calls for.
I don't really care much about the fact that I could put a beefier processor in it at this point but feel free to suggest something.
I have a trident 512KB ISA video card (TVGA9000 based, anyone have good drivers for NT4?)
3Com 10mbit NIC
Some form of Soundblaster AWE64 card
NT4 is just for the hell of it, something to gauge performance with "newer" OSes, its dual booting with dos 6.22/Win 3.11 on a 2.5GB drive. I'll probably test it out with 95 and 98 for amusement sake too.
I have both 3.5" and 5.25" floppy drives in the machine, while sadly I can only boot off of whichever one is at the end of the cable (and therefore A) I'm probably planning to leave the 5.25" as A and use this to go through a large collection of disks I was given containing all sorts of random things, including dos 3.3, 4.0, 5.0, Win 3.1, and various software packages.