Thread
64MB SIMMS in LC 550?
Just curious whether or not 64MB SIMMS are recognised on the 550 logic board or if 36MB (4 + 32) truly is the limit. Thanks!
If I'm not mistaken a 550 is basically an LCIII right? And it's max ram is 36mb so...
I am kind of think Charles said that a single sided 64MB SIMM might work in an LCIII... but maybe I dreamt that. Maybe he'll chime in. I know I tried a double sided one in mine and it failed.
yea i think it was trag... Trag was also the same guy that got 260 megs of ram to work in a quadra 605 if i remember correctly.
and then a little later on i repeated it in some thread. but i don't think i was ever able to come across a single sided 64 mb simm.
and then a little later on i repeated it in some thread. but i don't think i was ever able to come across a single sided 64 mb simm.
Thanks for the feedback! I'll likely stick with the 32MB SIMM in that case. If I've ever got a 64MB chip lying around, I'll test it and post my results. 
i'v tried double sided 64 meg simms to no avail… i tried 3 different 64 megs simms, no dice… but they worked great in the 475/605 so that is where they went.
Thanks, uni. I could always get a 64MB SIMM and drop it in one of the 475s and repurpose the 32MB chip for the 550.
I never tested memory in a 550; don't have one.
260 MB in the 605/475 was with a 72 pin SIMM doubler and there was no closing the lid. A single 128 MB SIMM is more practical.
Single sided doesn't mean anything with 64 MB SIMMs except in as much as it might correlate with non-composite and/or single vs. double banked. You pretty much always want non-composite though some old composite SIMMs will work (in some machines) and almost all 64 MB SIMMs are single bank -- all RAS wires/signals common amongst the chips on the SIMM.
Trag, out of curiosity, is there a specific type of 72-pin 128MB SIMM that seems to work better than others in the 475?
http://www.ebay.com/itm/128MB-FPM-MEMORY-NON-PARITY-60NS-SIMM-72-PIN-5V-32X32-/230649540963?hash=item35b3c8b163
I really like buying my ram from these guys.
right now i have 2 of these in my OC'd 6100, 256 megs of ram... sickness...
I really like buying my ram from these guys.
right now i have 2 of these in my OC'd 6100, 256 megs of ram... sickness...
I have some 64mb ram that will work in an LC575 (and Q605) but not in a 550. Draw your own conclusions!
you have 128 megs of ram in your LC575... if so ... COOL!
oh never mind, its got 2 simm slots for vram, not ram.
and.. if i am not mistaken... 128 megs of ram does not work in the LC575.
oh never mind, its got 2 simm slots for vram, not ram.
and.. if i am not mistaken... 128 megs of ram does not work in the LC575.
Could you drop 4 of those in a 650? Or is that where you would also need to add the ROM slot and use a dougg3 rom, bbraun style?right now i have 2 of these in my OC'd 6100, 256 megs of ram... sickness...
yes you can,, and yes you would need Doug's rom simm and Rob's 650/610/800 rom hack
and yes you would need Doug's rom simm and Rob's 650/610/800 rom hack 
Wow talk about memory leakage. lol.
Impressive stuff there, uni! Thanks for the link to the 128MB SIMM. I may need to find an alternative, though, as their shipping costs (~£25) are a bit steep for me, given that I would need - at most - one or two chips. In any case, I found this, but can't tell if it's double-height. In which case would it fit in the LC475?
http://www.ebay.co.uk/ulk/itm/161053502879
http://www.ebay.co.uk/ulk/itm/161053502879
I tried putting a several different 64MB SIMM in my LC III, some gave me a sad mac, others would just show up as 32MB (so 36MB total)... I was contemplating getting some different 128MB SIMMs and seeing if any of those could get at least recognized as 1 64MB (so 68MB total)... they are cheap enough on ebay, worst case I'm out $20 I guess
The LC 575 can accept a 128MB double banked 2k refresh SIMM for a total of 132MB.
See: http://colourclassicfaq.com/mobo/mystic.shtml
See: http://colourclassicfaq.com/mobo/mystic.shtml
I had very good luck with the HP D4293 and D4290 both manufactured by Samsung and also sold under an IBM part number as well. Samsung's part number on one of those (the 128 MB, I think) is KMM 53632000.
All that said I couldn't get the HP 128 MB SIMMs to work in the 6100, only the 475/605. I think the RAS lines are paired wrong for the 6100. There's some resistors and pads on the SIMM which look like they might control that but I never followed that line up.
Techknight: It's by design; Most of the RAM needs to be allocated to a RAM disk, or else stuff will crash.
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