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[Xenepp]

Hi all,

I have upgraded (if you can call it that) the DRAM in my SMC Pro to 32mb with some ram I pilfered from some old 4mb SIMMs. They are the same type but the response is 80n. The RAM already on the card is 70n, I assume this should not make too much difference with most games.

I also placed the caps from the SIMMs on the DRAM card since I assume these chips will need them.

My question is, should I expect to add any other parts to complete the upgrade? Like two more resistor networks on the SMC mainboard?

I ask since though it discovers the board as 32mb now and loads games, nothing actually runs, I get a black screen.

I know the SIMMs work since I tested them prior to my work and as far as I could tell, what I did should work ok.

The DRAM card does have slots for more resistor networks though, do I really require these to be added if I add more RAM? And even so, wouldn't the smaller games still work? I tested 4-16mb games and nothing runs.

Any help here is greatly appreciated!

-Joel

[kyuusaku]

I'm not sure what you mean by SMC Pro, but here are some issues upgrading a regular SMC or Supercom Pro 1:

-Super Magicom hardware and BIOS can't address 32M

-Super Magicom can't playback HiROM games (99% of >16M games), HiROM is implemented with a register bit feeding a multiplexer to shift address lines so it would be difficult to hack this in, not to mention adding support to the BIOS.

-80ns DRAM + the multiplexing logic is too slow for 120ns FastROM games (most games from 1993 onwards).

The resistor networks aren't necessary to fill, they're there to pull up/down the data bus for peculiar RAM.

[Xenepp]

Well I put it back to stock but realised.. it needed a game in the top run anyway

I don't feel too bad though, if it wasn't going to play anything over 16mb anyway then I guess all is well. It still works ok so no harm done. Would have been nice to play Super Metroid though.

Guess that means I have some spare 80n DRAMs for anyone with broken RAM cards.

-Joel