Compatible VRAM memory

[Steve]

Hiyas...

I have a Mach32 board that has two sockets for upgrading to 2mb vram.

The chips on the board are: HM514170AJ8

I had some Oki M514265BSL chips which I thought were the same kind, but they don't seem to work/allow higher resolutions.

Can anyone help me find/identify compatible ram chips? Much appreciated,

ps - I did find an ebay seller in the UK (little diode) and they want £24 for 1x chip!!! Can you believe it?

PXL_20220303_195635751.jpg

[PhilC]

@Steve are you sure the ram is plug and play and you don't need to jumper something on the board or blow a new eprom?

[Steve]

I just found a picture of @frank.lukas 's old card and noticed one thing! There is one extra resistor bridge/jumper below the ram which my card doesn't have. I wonder if it needs this to enable the extra ram banks.

nova.jpg

[Steve]

My card:

PXL_20220303_202634922.MP.jpg

[Steve]

@PhilC I think it might be a case of adding a 100ohm resistor, I'll try it out.

[Steve]

@PhilC update: no didn't work ;D

[PhilC]

@PhilC update: no didn't work ;D

Oh well, was just a thought

[frank.lukas]

There is no need to change anything. Insert the Ram and thats all. Test your card in a isa dos pc with the mach32 utility ...

[Steve]

Ok, tuns out the ram I put in is EDO and I need FPM memory. I'll try and track down the right stuff.. @frank.lukas I noticed on that old photo of your Mach32 it seemed to have NEC memory but it is too blurry to read. Would you know the number for those chips anymore? Thanks

[frank.lukas]

my card was different ...

https://forum.atari-home.de/index.php?topic=14398.0

1mb_dram_mach32.jpg