Left chip with sticker is NM27C256Q120. I believe right one also...
http://html.alldatasheet.com/html-pdf/54273/F … 27C256Q120.html
This is EPROM, You got to have eraser and programator to modify it.

I get this error when running EEPROM test on Mach64:

On the other hand Mach32 is doing fine:

JU11 jumpers are on the same place on both cards. Mach32 is jumpered while Mach64 is open. I searched for jumpers settings and can't find any. I also checked other pictures of Mach64 ISA cards and they all seem to have JU11 opened. I'm wondering if this is some EEPROM write protection.

@joc:
Are you sure these are EPROMs? Then it's no wonder it doesn't work 😵

So I should get two EEPROMs and make copies. What would be a compatible EEPROM?

There are two EPROMs on your card that contain the VGA BIOS. Those are not the chips that store the settings. the EEPROM (with the double E) should be one of the other smaller surface mount chips on the circuit board.

*edit 1*
On your Mach32, I am pretty sure it's the chip at U6, 93C56. However, on the Mach64 I am unable to find it, which makes me wonder if it's integrated into the IC.

*edit 2*
I think I found the problem! Your card does not have an EEPROM! The pads are empty! Look at the top left near the memory chips.
Compare to this image: http://www.vgamuseum.info/images/pirx/ati/02a … s_xpression.jpg

Anonymous Coward wrote:

*edit 2*
I think I found the problem! Your card does not have an EEPROM! The pads are empty! Look at the top left near the memory chips.

Remind me never to play a game of "eye spy" with you... 🤣

Anonymous Coward:
thanks for pointing it out. At least the card isn't flawed... but just missing a piece 😲 By the look of it, it seems it was never soldered.

I'll leave it as is. With optimized settings I'm sure it would be good in DOS too and even better in Windows.

Since it was never soldered in the first place, I wonder if it was intentional. Maybe there is an alternative to using the eeprom, like the way cirrus logic and tsengs work.

Jumpers... There is only one set JU11 and I can't find any description. Also they are present on all Mach32/64 cards.

I see some Mach64 ISA pop on the ebay... and they also don't have that eeprom soldered... weird 😕

I came from Amibay, I'll read it later on. It's really late in my country

Just to give an ending to this "problem" I solved many moons ago. It's actually not really a problem. This card doesn't use an EEPROM to save settings but you need newer drivers (V2.XX). The newer drivers save the settings to a file and settings are loaded through autoexec.bat (or manually if you choose) at boot. So it's all good in the end 🤣

@kixs sorry to drag up and old thread, but is it custom.com that loads the settings file?

I'm trying to get custom settings working on my Mach64 like you have done, but C:\ATI\UTILITY\CUSTOM.COM Q in autoexec.bat just seems to hang the machine... and I assume it's this which calls the EEDATA.EE_ which is created when you save settings using the install programme?

I think the problem is when the install program loads it says it can’t find custom.vde (despite that file being present in the dir and also in the vde subdirectory) and it then says there isn’t a VDIF-compatible monitor attached (I’m using a dell 2001fp lcd). So when custom.com tries to load EEDATA.EE_ it’s falling over at the monitor stage of the settings file?

Does this make any sense?

I don't know from memory the exact procedure and filenames. But did you setup the card via install.exe? You should set the correct resolutions and frequencies first.

i tried to set up the monitor using install.exe, but it doesnt allow me to do the Quick Setup because it says on loading that it can't find Custom.vdb and then it complains that a vdif compatible monitor is not attached.

Can you recall where custom.vdb is meant to be? i have it in the directory but install doesnt seem to see it!

I can try later tonight (if time permits) 😉

Do you have the latest drivers? I used V2.12.

I'm on 2.2 according to Install.exe

trixster wrote on 2021-11-21, 15:15:

I'm on 2.2 according to Install.exe

I've tested my ISA ATI Mach64 2MB DRAM card. This one has EEPROM so it's not the same as yours. I run install ver 2.12 and I get the same VDIF error. Then I searched my other Mach64 drivers and found the attached one (V3.03?). With this one I can select custom monitor/resolutions and I think it should work 😉

Oh brilliant! Thanks very much! I will try this tonight and report back