First post, by Siran
After I've recently found some of my old PCs while clearing out the attic I came across my very own first PC: An AMD 386 DX 40 on a 4386-VC-HD board with 8MB RAM, a "HighScreen Blaster 3.0" (Soundblaster 2.0 clone based on CPS' Soundblaster 2.5), 120MB Connor HDD and a Trident TVGA 9000B with a whopping 512KB VRAM.
I even got it to post, albeit the dreaded Dallas RTC reared its ugly head and greeted me with a CMOS battery error. I then opened the case and to my great surprise realised that not only did my late father who used it after I got a new PC upgrade it with a 387 FPU but the board could also house a 486 DX/2 66 instead of an FPU:
According to the manual (thank got I kept it) if you want to install a 486 DX/2 66 you'd have to switch two resistors, swap the oscillator to a 33MHz model (currently it has a 80MHz model installed due to the 386 DX 40) and set the jumpers accordingly:
Apart from the switching resistors, setting jumpers and swapping the oscillator do I need to do anything else before upgrading the board? For instance when I looked at the BIOS chip on the mainboard I got worried since it says "386DX". Does that mean I also need a new BIOS for a potential 486 DX/2 upgrade? I've found several pictures and a video by VSwitchZero that show that there are indeed BIOS chips that are labeled "486DX". See his video here (he also has a 386 installed): https://youtu.be/MV8nkl1Cjw0. Here's a picture of my BIOS chip:
If I need a new BIOS - can I flash it? The first time I flashed a BIOS was on a later Asus T2P4 board (that I also found in the attic) so I'm not sure if it is even possible and if it is what program to use. If it can't be flashed would I need someone with an eeprom flash tool? I've found several BIOS versions for the board here: https://theretroweb.com/motherboards/s/fic-4386-vc-hd.
I'm planning on tinkering a bit with the board. First, I'm getting the Dallas IC replaced so that I can properly use it, then I plan on upgrading the cache to a full 256K. I'll also need an HDD replacement since the trusty 120MB Connor HDD did not survive the almost 30 years in the attic. I'm torn between using an old 500MB IDE drive I have left, an IDE/SD-card adaptor and going all in with an old Compaq SCSI ISA controller that has a AIC-6260AL chipset since I still have a Seagate Cheetah 9GB with 10K RPM (that needs extra cooling and is loud so I guess I'll skip that) and an IBM Ultrastar with 18.2 GB. Even though these are U2W HDDs I recently got a working cable to attach them to a standard SCSI 50-pin controller.