Compatible VRAM memory

[czietz]

Also be sure to pay close attention to the pinout. I've highlighted the differences between HM514170AJ and M514265BSL:

ram-HM514170AJ.PNG (24.65 KiB) Viewed 2279 times

ram-M514265BSL.PNG (47.94 KiB) Viewed 2279 times

[Steve]

Also be sure to pay close attention to the pinout. I've highlighted the differences between HM514170AJ and M514265BSL:

ram-HM514170AJ.PNG
ram-M514265BSL.PNG

Hi Christian,

I already linked the CAS lines together as per suggestion elsewhere which hasn't helped, are you saying I should also link the LWE/UWE lines too?

[czietz]

I already linked the CAS lines together as per suggestion elsewhere which hasn't helped, are you saying I should also link the LWE/UWE lines too?

No. Neither one, nor the other will work. Unfortunately, you need to get RAM chips with the appropriate pinout.

[mrbombermillzy]

@Steve (as usual ), if you can hang on till next week, I will try to dig out some of this style RAM I pinched from a (IIRC) S3 Virge 2/4Mb PCI card.

May be cheaper than the horrendous Ebay prices if it's a match, but I'm not sure the size or what it is (FP/EDO/?), other than the same package type.

[Steve]

@Steve (as usual ), if you can hang on till next week, I will try to dig out some of this style RAM I pinched from a (IIRC) S3 Virge 2/4Mb PCI card.

May be cheaper than the horrendous Ebay prices if it's a match, but I'm not sure the size or what it is (FP/EDO/?), other than the same package type.

Ah cool thanks man appreciate it.. yeah I was going to have to start looking to buy cards to steal ram from.

[Steve]

I already linked the CAS lines together as per suggestion elsewhere which hasn't helped, are you saying I should also link the LWE/UWE lines too?

No. Neither one, nor the other will work. Unfortunately, you need to get RAM chips with the appropriate pinout.

Hi Christian,

Sorry to be a pain, I found some originals in Canada for a good price but they want £20 postage
You wouldn't happen to be able to help me find a compatible type in Europe by any chance? On ebay.

Thanks

[mrbombermillzy]

Managed to dig them out as I had a few minutes to myself.

P1040206.JPG (224.45 KiB) Viewed 2173 times

They seem to be 5V 256K×16 CMOS DRAM (EDO) chips according to the datasheet:

https://www.dexsilicium.com/Alliance_AS4C256K16E0.pdf

No good then, as you need fast page.

EDIT: Also, if you are looking to buy elsewhere; although my RAM knowledge is a bit rusty, you may want to check that the CAS/RAS timings match with whatever RAM is on there already.

[Steve]

@mrbombermillzy I bought a PCI Ati mach 64 off ebay just now, I can't quite see the ram markings I'm just crossing my fingers that they'll be the right type. If not I'll bite the bullet and buy 2x from the Canadian seller and pay the £20 postage.

[mrbombermillzy]

@mrbombermillzy I bought a PCI Ati mach 64 off ebay just now, I can't quite see the ram markings I'm just crossing my fingers that they'll be the right type. If not I'll bite the bullet and buy 2x from the Canadian seller and pay the £20 postage.

I'm guessing it's a bit of a gamble, so I'll keep my fingers crossed for you too.

Next time, maybe ask the seller for closeups? (I did that when browsing through dead STFM boards on Ebay for shifter models).

Most of the time, the seller is happy to oblige.

[Steve]

Darn it... the ram on this board is:

vram.png (41.22 KiB) Viewed 2090 times

Which I think also will probably not be correct :/