Basically you want 4 DIP24 chips of 256x8 45ns FPM DRAM. There is one seller in eBay with the ICs you need, even the same manufacturer, but the minimum quantity is 15 pcs. for about $35 so I'm not sure if it's worth it as you will have 11 chips left over.

Search for V53C8256HP45.

I have this board

I put a copy of the BIOS here:
https://www.vogonsdrivers.com/getfile.php?fileid=2145

I had some spare chips. Siemens 514256B-60

I put them in, but the board didn't detect them. I guess they are too slow ?

I figured it would at least see them.

douglar wrote on 2024-01-30, 18:36:

I have this board DXL9IL677.png […]
Show full quote

I have this board
DXL9IL677.png

I put a copy of the BIOS here:
https://www.vogonsdrivers.com/getfile.php?fileid=2145

I had some spare chips. Siemens 514256B-60

I put them in, but the board didn't detect them. I guess they are too slow ?

I figured it would at least see them.

Can you post a picture from your card?
What is the RAMDAC?
With a 80MHz RAMDAC I am sure, that the upgrade is useless, you won't have additional resolutions/modes.
Even when there is a 110MHz RAMDAC on the card, I guess that the upgrade will be useless.

CoffeeOne wrote on 2024-01-30, 19:44:

Can you post a picture from your card? What is the RAMDAC? With a 80MHz RAMDAC I am sure, that the upgrade is useless, you won't […]
Show full quote

Can you post a picture from your card?
What is the RAMDAC?
With a 80MHz RAMDAC I am sure, that the upgrade is useless, you won't have additional resolutions/modes.
Even when there is a 110MHz RAMDAC on the card, I guess that the upgrade will be useless.

There is a picture of the card in the previous post. Here's a zoom on the RMADAC:

http://www.bitsavers.org/components/sierra/SC15025_15026.pdf

At first I thought it might be the 125 or 110MHZ version of the RAMDAC, but now that I zoom it, I see that "80" stamped on the chip. That does make the project less exciting.

douglar wrote on 2024-01-30, 20:05:

There is a picture of the card in the previous post. Here's a zoom on the RMADAC: ramdac.jpg […]
Show full quote

CoffeeOne wrote on 2024-01-30, 19:44:

Can you post a picture from your card? What is the RAMDAC? With a 80MHz RAMDAC I am sure, that the upgrade is useless, you won't […]
Show full quote

Can you post a picture from your card?
What is the RAMDAC?
With a 80MHz RAMDAC I am sure, that the upgrade is useless, you won't have additional resolutions/modes.
Even when there is a 110MHz RAMDAC on the card, I guess that the upgrade will be useless.

There is a picture of the card in the previous post. Here's a zoom on the RMADAC:
ramdac.jpg

http://www.bitsavers.org/components/sierra/SC15025_15026.pdf

At first I thought it might be the 125 or 110MHZ version of the RAMDAC, but now that I zoom it, I see that "80" stamped on the chip. That does make the project less exciting.

The picture is pretty bad, hard to see something, also the Bios was missing therefore I thought it is not the actual card, but never mind.
I mean the upgrade is 99% in vain, but you could try it and then post into my "useless upgrade thread" Vesa Local Bus graphics card - upgrade video memory

OK, so maybe one of the jumpers / dip switches has to be moved for 2 MB?

CoffeeOne wrote on 2024-01-30, 20:12:

The picture is pretty bad, hard to see something, also the Bios was missing therefore I thought it is not the actual card, but never mind.
I mean the upgrade is 99% in vain, but you could try it and then post into my "useless upgrade thread" Vesa Local Bus graphics card - upgrade video memory

OK, so maybe one of the jumpers / dip switches has to be moved for 2 MB?

Sorry about the poor quality. The Bios was out because I was up loading it.

This card isn't identical to mine, but all of the jumper labels are the same. I used it to get the refresh rates set. https://th99.dosreloaded.de/v/U-Z/50034.htm

There's nothing these about 2MB other than adding the chips. I guess either the memory was too slow or some of the chips are bad or the sockets are dirty.

douglar wrote on 2024-01-30, 20:32:

Sorry about the poor quality. The Bios was out because I was up loading it. […]
Show full quote

CoffeeOne wrote on 2024-01-30, 20:12:

The picture is pretty bad, hard to see something, also the Bios was missing therefore I thought it is not the actual card, but never mind.
I mean the upgrade is 99% in vain, but you could try it and then post into my "useless upgrade thread" Vesa Local Bus graphics card - upgrade video memory

OK, so maybe one of the jumpers / dip switches has to be moved for 2 MB?

Sorry about the poor quality. The Bios was out because I was up loading it.

This card isn't identical to mine, but all of the jumper labels are the same. I used it to get the refresh rates set. https://th99.dosreloaded.de/v/U-Z/50034.htm

There's nothing these about 2MB other than adding the chips. I guess either the memory was too slow or some of the chips are bad or the sockets are dirty.

You need Mosel Vitelic V53C104HP45, unfortunately those are not easy to get.
It is really interesting for what purpose you can upgrade the card.
It is a 32bit controller, so the second MB will not increase the bandwidth.
It is interesting that refresh rates can be set via Jumpers. But not for 1280x1024, so I guess that is always interlaced. But why then 2MB?

If anyone runs across a BIOS for this card that newer that 9/13/93, please post it.