+remowilliams Posted November 14, 2008 Share Posted November 14, 2008 (edited) So I finally have a Mega STE. It came with a working ST157M HDD, and 2MB of memory. So after digging through the RAM pile I came up with some 30 pin SIMMs that looked to be in the ballpark. The system seems to mostly work with them in, as I've run a number of things that require 4MB of RAM and that's how much is reported in utilities. Sometimes though on power on there is screen garbage on the white boot screen. Are these modules close enough, or do I need the specific Atari supplied SIMMs? Also - is there a memory test program that works on the STE? I tried using ramtest.tos (which I've used in the past on other machines) and it just seems to give 2 bombs on the STE. And are there any DIP switch or jumper changes needed to the motherboard when adding RAM? Edited November 14, 2008 by remowilliams Quote Link to comment Share on other sites More sharing options...
Rybags Posted November 14, 2008 Share Posted November 14, 2008 Looks like those are non-parity SIMMs - most of the ones you come across have parity. It's pretty easy to just tell visually since the parity generating ones have an odd number of memory chips, usually 3 or 9. No idea here whether or not the STe works with the parity ones - but in any case it would be best to stick to the same type rather than mixing them. Quote Link to comment Share on other sites More sharing options...
+remowilliams Posted November 14, 2008 Author Share Posted November 14, 2008 The SIMMs that came in the unit don't appear to be parity which is why I chose the add ins from the pile. Here's a pic of the new and old, with the old in slots 1 and 3. The new ones are significantly faster (60 vs 100) but I didn't think that should matter. It seems that if the unit powers up without any garbage on the boot screen, that it functions properly afterwards. I'd really like to run a RAM test though. Quote Link to comment Share on other sites More sharing options...
+poobah Posted November 14, 2008 Share Posted November 14, 2008 The SEC memory is EDO The TI is FPM No mixie-mixie! Quote Link to comment Share on other sites More sharing options...
+remowilliams Posted November 14, 2008 Author Share Posted November 14, 2008 Ah. Yeah I was wondering about FPM/EDO. Couldn't tell what the SEC was though. Guess I need 2 FPM SIMMs. It's funny that it actually does work most of the time though. Quote Link to comment Share on other sites More sharing options...
Lynxman Posted November 21, 2008 Share Posted November 21, 2008 The SEC memory is EDOThe TI is FPM No mixie-mixie! The SEC memory is FPM. EDO Ram was never mounted on 30 pin Simm! KM41C16000AK is 16MBitx1 FPM, please have a look into the datasheet! KM41C16003xx is 16MBitx1 EDO Using EDO mixed with FPM is no problem if the System do not provide EDO. EDO Ram includes FPM function. Please have a look into the datasheet. Ah. Yeah I was wondering about FPM/EDO. Couldn't tell what the SEC was though. Guess I need 2 FPM SIMMs. It's funny that it actually does work most of the time though. The SEC (Samsung) 30 pin Simm in your picture are 16MB(!) Simm. Very rare! If you want to use it in a STE/Mega STE System, you should connect the highest Adress line (A11) to VCC or GND. A11 is Pin 24. Quote Link to comment Share on other sites More sharing options...
atarian63 Posted November 21, 2008 Share Posted November 21, 2008 The SEC memory is EDOThe TI is FPM No mixie-mixie! No Mixie -mixie! Funny! Quote Link to comment Share on other sites More sharing options...
+remowilliams Posted November 21, 2008 Author Share Posted November 21, 2008 You know, I sort of thought that EDO would fall back to FPM but it's been such a long time. The SEC (Samsung) 30 pin Simm in your picture are 16MB(!) Simm. Very rare! I tried to find datasheets but just kept getting those stupid part wholesaler sites with no info. So I suppose I accidentally upgraded my MSTE from 2MB to 34MB... Now I'm even more surprised that it seemed to work with those in there. Quote Link to comment Share on other sites More sharing options...
+poobah Posted November 21, 2008 Share Posted November 21, 2008 The SEC memory is FPM. EDO Ram was never mounted on 30 pin Simm! Using EDO mixed with FPM is no problem if the System do not provide EDO. EDO Ram includes FPM function. Please have a look into the datasheet. With all due respect, you are quite wrong about that. I have a pile of 30 pin EDO simms here that beg to differ with you. (And before you get all "read the datasheet" happy - I bought some of them brand new, back in the age of 30 pinners.) You *might* get away with running four properly wired up EDO simms that support FPM (which I've never seen, but may exist). Mixing them with FPM on the same board won't work. Quote Link to comment Share on other sites More sharing options...
+remowilliams Posted December 12, 2008 Author Share Posted December 12, 2008 If you want to use it in a STE/Mega STE System, you should connect the highest Adress line (A11) to VCC or GND.A11 is Pin 24. Got back to this today, using 4 of the SEC SIMMS. I tried tying A11 to VCC or GND, it didn't seem to make a difference in operation. It looks like on first boot it always comes up as 4MB without any screen trash on the white boot screen, after a reset it also works correctly. If I power the unit off however, if I don't wait at least 2 minutes before powering it back on, I get screen trash ranging from slight to massive. Quote Link to comment Share on other sites More sharing options...
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