Hi, I've been trying to upgrade a 32Mb SWC DX2 ram board to 64Mb. I believe there are several versions of the boards, but I'd like to compare (I currently have a 32Mb and a 64Mb, which are utterly different). Would be great if anyone with a dx2 unit could take a snap? Cheers, Silver
Why do you think there's several versions? I've seen a lot of 64M boards and they've all been the same. The 64M board is utterly different because it has to be. Quickly looking at it, on the 157 only one bit is used, presumably to multiplex DRAM A11. The 08 gates signals to decode the chips since the old 1Mx4 signals can't be used anymore, and the 20V8 perhaps alters the refresh logic. If you want to upgrade your 32M, all you have to do is figure out the 20V8 which couldn't be very hard since there only appears to be 3 outputs used and they may not even be registered. Any way you look at it, you'll have to partially pull apart your 64M board.
I've had an email from someone describing that they upgraded their 32Mb board - but from their description their 32Mb board was similar to the 64Mb board I have, but different to my 32Mb board. Based on this, I assumed their were variants of the 32Mb board at least. I was thinking the 157 multiplexer on the 32Mb board implied there was scope to add more 4mb x 4bit cmos d-ram chips, but I have not looked into it. Do all your 64mb boards have points soldered to the dx2 mainboard?
Ok Cheers, looks like my assumption was wrong, thanks for your input. Not too fussed as there is not much benefit to 64mb on a dx2.
