Hey guys.  Remember when I announced that I was working on my emulation project MVCE (Multiple Video Card Emulator)?  Well, as of late I've been a bit too busy to work on it (unemployed and trying to start a business), but in my spare time, I'm trying to see if I can get my SST-1 emulation code working on an existing PC emulator to make sure it works okay.  The reason I've chosen SST-1 as the first card I want to emulate is because the Voodoo1 is the simplest 3Dfx card out there, VGA is handled by a seperate card, and the fact that it has no BIOS by design (making life much easier).  After that, I was going to attempt a Diamond Viper v330 (Riva 128).

So, here's my question to all of you, has anyone ever programmed a Voodoo1 directly?  I've seen the assembly code from that guy that learned to program his Voodoo3, but the Voodoo3's registers are mostly the same, it still works a bit differently than the Voodoo1.  I did download the voodoo graphics reference data sheet from the site that explains all the registers and stuff, but is there a programming guide for the voodoo1 like there is for the voodoo3?  Btw, are there any open source drivers for the Voodoo1?  The biggest problem I have is understanding the delta registers (i.e. dRdX/Y, dGdX/Y, dBdX/Y, etc.)  Do you add/subtract this register based on what direction the next vertex is compared to the current vertex?  All of the other registers I can understand okay, but I don't understand these.

"Why do you want to program the Voodoo1 directly?"  It's easier to emulate something when you've programmed it on it's lowest levels so you know exactly how it works.  Then when the code works on the real Voodoo1 (which I'm currently bidding on at eBay), I can test it on my emulator and know exactly what to expect.  Thanks.

Shogun.