I'll dump the bios when I get a chance and poke around with my clumsy binary ready skills to see if I can spot anything.

douglar wrote on 2020-11-05, 21:49:

I'll dump the bios when I get a chance and poke around with my clumsy binary ready skills to see if I can spot anything.

OK, I feel more stupid than usual. Perhaps I truly have begun to enter my dotage.

Here's the deal. The other chip is not a rom at all.

I had it in my reader and got out my magnifier to read the small print. Just about rammed my glasses through my head with the resulting face palm.

The other chip is the ATI68830 RAMDAC.

So the reason for the double image is pretty freakin clear in hindsight. Double image because I had two ramdacs.

All I had to do was pull the ATI68830 and it was all good. Both the TLC34075 and the TLC34076 were compatible with the Mach32 card all along.

If anyone wants a spare TLC34075 for their mach32 card, let me know and I'll be happy to mail it away so there's fewer reminders of this incident in my life =)

Here's a link to the rom that I dumped--

https://www.dropbox.com/s/fv6m6uwondp5bd5/VLB … 0.1993.BIN?dl=0

I read this somewhere and was trying to find the link to where I'd seen it, but yeah the second dip socket was either labelled even BIOS or the original RAMDAC.

Glad you got it sorted!

That said, these kinds of debugging hijinks and occasionally eureka moments are why we do this right!?

I tested a VLB Mach32 EXM195a 2MB VRAM:

against a VLB Mach32 EXM229 2MB DRAM:

on a 486dx2-66 equipped Shuttle HOT 419 v1.0 mobo utilizing a Opti 82C894 chipset & 512kb cache.

I compared landmark scores--

• Mach32 EXM195a VRAM -- 7,740 char/ms - 7740 is the slowest VLB score that I've seen
• Mach32 EXM229 DRAM -- 10,922 char/ms - 40% faster

I also did the high quality doom benchmark on both cards.

• Mach32 EXM195a VRAM -- 2,869 realtics -- One of the best VLB scores
• Mach32 EXM229 DRAM -- 2,693 realtics -- The best VLB score I have seen on this system

Not sure why the landmark scores are so bad but the doom scores are so good.

Would something like UNIVBE 6.7 improve landmark scores?

Aren't the landmark graphics scores just based on text modes?
Since when was landmark a reliable measure of anything anyway?

douglar wrote on 2020-11-06, 20:06:

OK, I feel more stupid than usual. Perhaps I truly have begun to enter my dotage. […]
Show full quote

douglar wrote on 2020-11-05, 21:49:

I'll dump the bios when I get a chance and poke around with my clumsy binary ready skills to see if I can spot anything.

OK, I feel more stupid than usual. Perhaps I truly have begun to enter my dotage.

Here's the deal. The other chip is not a rom at all.

I had it in my reader and got out my magnifier to read the small print. Just about rammed my glasses through my head with the resulting face palm.

The other chip is the ATI68830 RAMDAC.

Photo Nov 06, 2 51 54 PM.jpg

So the reason for the double image is pretty freakin clear in hindsight. Double image because I had two ramdacs.

All I had to do was pull the ATI68830 and it was all good. Both the TLC34075 and the TLC34076 were compatible with the Mach32 card all along.

If anyone wants a spare TLC34075 for their mach32 card, let me know and I'll be happy to mail it away so there's fewer reminders of this incident in my life =)

Here's a link to the rom that I dumped--

https://www.dropbox.com/s/fv6m6uwondp5bd5/VLB … 0.1993.BIN?dl=0

Thanks for the ramdac, can't wait for the extra ram to get here so I can upgrade my card!

I have tried a Ti TLC34076-170FN, it has seemed to work as the system posted and display with the Ti ramdac. Need to test further in benchmarks and games.
Remove JU6 jumper and U32 ATi68830 (if present) to use the Ti TLC3407x chips in U30 PLCC socket.

Both the Ti TLC34076 and TLC34075 are pin compatible and feature set compatible with the ATI68875.
Someone asked about the Ti TLC34058, this chip is NOT compatible in any way. (Ask me how I know.)

I have a Mach32 VLB. Mach32 2200688003 (9245)
FCC ID: EXM195
ATI PN: 1090019530
ROM: VLB Mach 32(A) 113-19500-100 (C) 1992.

Originally had 1MB and the 68830P-80 Ramdac in U32.
Upgraded to 2MB and the TI TLC34076-170FN.

I have post tested with TC524258BZ-80 (early 95) and MT42C4256Z-8 (mid 92) ZIP VDRAM chips.
They are Video Dram, Fast Page, 256Kx4bit, 28pin ZIP.

At the time of this post I have 12 of the TI TLC34076-170FN chips.

I have ATI Mach32 in my ICL D4/66XGi, on motherboard and VLB connected. It's sick fast BUT not that compatible with demoscene productions.

I still have the Ramdacs available. Not able respond to DM at this time.

Asmodeusbell wrote on 2023-08-21, 16:44:

I still have the Ramdacs available. Not able respond to DM at this time.

Hello,

I have a similar card as posted above with VRAM:
2MB, no sockets all 2MB soldered.
RAMDAC TLC34076-135FN.
But soldered, no socket.
Would the 170MHz RAMDAC give some additional modes?

Anyway I am not going to desolder the existing RAMDAC, so upgrading is not an option.

CoffeeOne wrote on 2023-08-22, 10:09:

But soldered, no socket.
Would the 170MHz RAMDAC give some additional modes?

Anyway I am not going to desolder the existing RAMDAC, so upgrading is not an option.

Can you post a picture of your board? If there's a socket for a new ramdac, there's probably a way to disable the one soldiered on your board.

If you have 2MB of RAM on your card, the 170Mhz Ramdac will allow for >=60Hz refresh rates at 1280x1024x8 or 1024x768x16.

If you only have 1MB of RAM on your card, you can't do those modes, so there's less benefit to the faster RAM DAC.

douglar wrote on 2023-08-22, 17:07:

Can you post a picture of your board? If there's a socket for a new ramdac, there's probably a way to disable the one soldiered […]
Show full quote

CoffeeOne wrote on 2023-08-22, 10:09:

But soldered, no socket.
Would the 170MHz RAMDAC give some additional modes?

Anyway I am not going to desolder the existing RAMDAC, so upgrading is not an option.

Can you post a picture of your board? If there's a socket for a new ramdac, there's probably a way to disable the one soldiered on your board.

If you have 2MB of RAM on your card, the 170Mhz Ramdac will allow for >=60Hz refresh rates at 1280x1024x8 or 1024x768x16.

If you only have 1MB of RAM on your card, you can't do those modes, so there's less benefit to the faster RAM DAC.

Picture!

CoffeeOne wrote on 2023-08-22, 18:06:

Picture!
PXL_20230822_180211375.jpg

That's a nice clean looking card. I realize now that I jumped back into a conversation and had missed a post.

I thought you were talking about upgrading from a slower 85MHz ramdac, which would have been in a DIP28 socket in the empty space right below your 135MHz ramdac.

But you were not talking about that. You have a 2MB card with the 135MHz ramdac, and you can do the good refresh rates at 1280x1024x8 and 1024x768x16.

You are talking about adding a over spec'd 170MHz ramdac. Interesting idea. Not sure how it would help though.

If you were having image quality problems, maybe, but all the output I've seen with the 135MHz has been well above average.

If you wanted to try to reach any modes that were not available on the 135MHz ramdac, I imagine you would need to make a custom BIOS or Driver. The current software probably won't know about the higher speeds.

The TI TLC34076-170FN doesn't add anything over the 135 speced part. It was only ones I could find, and was only in bulk. To replace the 68830P-80 Ramdac.

If you already have the TI TLC34076-135, no real point of getting the 170 ramdac. If you have a card with the ATI 68830P ramdac and have a PLCC socket for the Ti ramdac, then yes, either the TLC34076-135 or 170 is an upgrade.