VOGONS


First post, by badmojo

User metadata
Rank l33t
Rank
l33t

I'm a total noob when it comes to EPROMs but I have 2 PCI VGA cards here which are fundamentally the same hardware, but which have different BIOSes, one of which performs better than the other. I've tested this by swapping the BIOS chips so I know it works - what I want to do is copy the good BIOS, burn it to a new EPROM, and put the copy into second card.

The card in question is below - I've done a bit of reading here and and people are recommending the TL866CS programmer which I can find easily online.

What I want to confirm before I dive in though is:

- is this programmer suitable for the sort of chip I need? It obviously needs to be able to read the old one and write a new one. Alternatively I could just skip the read and try and ones uploaded here: http://www.vgamuseum.info/index.php/cpu/item/ … logic-ark2000pv
- what sort of chip do I need??

Thanks for any help.

IMG_2676.jpg

Life? Don't talk to me about life.

Reply 1 of 12, by jakethompson1

User metadata
Rank Oldbie
Rank
Oldbie

Here in the US AT27C512R chips in 28-pin DIP format are $2.80 apiece. Those chips are one-time programmable.
28-pin chips can be in multiple capacities, 512 kilobits (64 KB) being the biggest.
If the video BIOS is smaller than that, it's best practice to concatenate multiple copies of it to fill the whole chip.
The TL-866 II is popular and works, I don't know if it is any different than what you have proposed.

Reply 3 of 12, by maxtherabbit

User metadata
Rank l33t
Rank
l33t

Yeah that's perfect. Just bare in mind it's a one time programmable chip. So don't fuck up your settings in the programmer software

Reply 4 of 12, by badmojo

User metadata
Rank l33t
Rank
l33t
maxtherabbit wrote on 2021-11-14, 03:40:

Yeah that's perfect. Just bare in mind it's a one time programmable chip. So don't fuck up your settings in the programmer software

Don't worry I never make mistakes 😂

I'd better buy a few chips.

Thanks very much for the help guys 👍

Life? Don't talk to me about life.

Reply 5 of 12, by retardware

User metadata
Rank Oldbie
Rank
Oldbie
badmojo wrote on 2021-11-14, 04:05:

I'd better buy a few chips.

Or consider using EPROMs (UV Erasable PROMs) or EEPROMs (electrically erasable PROMs) instead of OTPROMs (one-time programmable ROMs).
If you have a stash of defective or otherwise worthless boards/cards, then it is highly likely that one or more of these have such a thing which can be reused.

Reply 6 of 12, by Doornkaat

User metadata
Rank l33t
Rank
l33t
badmojo wrote on 2021-11-14, 04:05:

Don't worry I never make mistakes 😂

I'd better buy a few chips.

😂 I can very much relate to this.

Reply 7 of 12, by Nemo1985

User metadata
Rank Oldbie
Rank
Oldbie

That's very interesting, are you willing to share both bios?
The one with higher performance and the other?
You can take the dump with nssi program.

Thank you

Reply 8 of 12, by badmojo

User metadata
Rank l33t
Rank
l33t
Nemo1985 wrote on 2021-11-14, 09:44:

That's very interesting, are you willing to share both bios?

Sure I'm happy to share them if I get that far - I've ordered the unit so I'll see how I go.

Don't get me wrong the performance difference is tiny, but it's measurable and therefore enough to keep me up at night 😋

Life? Don't talk to me about life.

Reply 9 of 12, by Nemo1985

User metadata
Rank Oldbie
Rank
Oldbie
badmojo wrote on 2021-11-14, 11:12:
Nemo1985 wrote on 2021-11-14, 09:44:

That's very interesting, are you willing to share both bios?

Sure I'm happy to share them if I get that far - I've ordered the unit so I'll see how I go.

Don't get me wrong the performance difference is tiny, but it's measurable and therefore enough to keep me up at night 😋

And that's because interesting. 😀
Anyway to make a dump of the bios you do not need anything special, with nssi, it makes the dump from the running pc. No programmer neded.

Thank you kindly.

Reply 10 of 12, by jesolo

User metadata
Rank l33t
Rank
l33t
Nemo1985 wrote on 2021-11-14, 11:30:
And that's because interesting. :) Anyway to make a dump of the bios you do not need anything special, with nssi, it makes the d […]
Show full quote
badmojo wrote on 2021-11-14, 11:12:
Nemo1985 wrote on 2021-11-14, 09:44:

That's very interesting, are you willing to share both bios?

Sure I'm happy to share them if I get that far - I've ordered the unit so I'll see how I go.

Don't get me wrong the performance difference is tiny, but it's measurable and therefore enough to keep me up at night 😋

And that's because interesting. 😀
Anyway to make a dump of the bios you do not need anything special, with nssi, it makes the dump from the running pc. No programmer neded.

Thank you kindly.

Agreed. I would suggest that your temporarily disable Mainboard BIOS & Video card BIOS shadowing in the CMOS setup before dumping the BIOS with NSSI.

Reply 11 of 12, by maxtherabbit

User metadata
Rank l33t
Rank
l33t

Dumping PCI video card BIOSes with NSSI is not reliable. The EPROM on the PCI cards often contains more data than the card exposes to the bus.