S3 Virge DX overclocking and upgrade

My DOS box now has a first generation 3dfx, so I thought it was time to make sure the primary graphics adapter was keeping up with it. I’d also had some compability issues, not solved by S3VBEFix. So a new BIOS and overclocking was overdue. Go for the 2.01.07 and not the newest BIOS to skip on brightness issues.

The new firmware sourced on Vogons and flashed to a Winbond W27E257 with my Xgecu T56.

As the the 83 Mhz version runs hotter than the stock 50 Mhz I removed the sticker with some label off, and attached a heatsink with some thermal adhesive.

Rockwell AIM 65 keyboard models

After researching a small lot of Rockwell AIM 65 R6500 Advanced Interactive Microcomputer, there seems to be small variations. Those deserve to be documented. First out, the keyboard variations.

  • Futaba FK-2054 keyboard found in serial number A43648, A43651, A43653 and A43654.

  • Stackpole Components 86-90-0030 keyboard found in serial number A31072.

  • HI-TEK 373-70125 keyboard found in serial number A11220.

Futaba FK-2054 key side. Notice the straight line in Q and the plastic keyboard frame.

Futuba FK-2054 solder side.

HI-TEK Part.No. 373-70125 key side. Notice the curly line in Q.

HI-TEK Part.No. 373-70125 solder side.

Stackpole Components 86-90-030 key side. Notice the curly line in Q key.

Stackpole Components 86-90-030 solder side.

DOS box upgrades

The DOS box is coming along nicely. After buying and failing with several COASt modules, I found one that worked, so the machine is now running a full 512KB Level 2 cache. I finally got hold of a CT3900 with 8MB of RAM fitted, a S3 ViRGE with 4MB of RAM, The 3Com NIC has been replaced with a gigabit Intel NIC running the E1000PKT packet driver. The leaking caps has been replaced. The noisy fans replaced with Noctua fans. For the PSU I soldered the NA-RC10 adapter directly to the PCB as there where no FAN connector. The equally noisy 1,2 GB IDE drive has been disconnected, and I am now running of a 2 GB DOM instead. I also burned a new upgraded BIOS to an empty SST29EE010-150 chip. I’ve also added a PS/2 port so I can use a more modern MX518 mouse (through an adapter). The PS/2 connector was not easy to find, as the FIC motherboard has a fine pins in a row configuration, that differs from the previous generation motherboards. I could not find the correct pinout in any manuals, so I had to test with a multimeter and change the connector.

Building a DOS box

I recently bought a lot of 5 old PCs. One of which was a Targa X system, with an AT motherboard. My brother was complaining about Warcraft 2 not running correctly in DOSBox, so why not build a real DOS computer. The computer proved hard to get started. Upon inspection it was easy to see that it was because of leaking caps. I bought a set of new Panasonic caps off ebay. Replacing the caps made the system boot up without any trouble. Other improvements: The front had a teared up energy star logo, streaks from office chairs rubbing off on the front. Also a Norman anti-virus sticker. I cleaned it all off.

Targa x System, all cleaned up!

As for upgrades, I switched the IBM 6x86 P166+ running at 133Mhz for an Intel Pentium MMX 233Mhz. The system was fitted with 96MB EDO across four 72-pin SIMM sticks. This makes the system slow, as the FIC PT-2006 motherboard and its i430VX chipset can only cache the first 64MB of RAM address space. Thus I removed two 16MB sticks to speed the system up. The motherboard also have a free slot for a 256KB COAST cache module, I’ll see if I can get a hold of one of those. Also, I found the motherboard has an USB header. The connector does not have the alignment pin, but the pinout seems standard, so I fitted an 2x USB bracket. in the rear. The passive CPU cooler was replaced with a Socket A cooler master cooler from my scrap bin.

Leaking capacitors and a gold cap IBM 6x86

Leaking capacitors and a gold cap IBM 6x86

On the wishlist is a 256KB COAST 3.0 module, a Sound Blaster AWE32 non-PNP and a network bootable NIC for PXE booting some tools.