EDO memory and regular memory

Motero

Senior member
Jan 31, 2001
889
0
0
I have an IBM Thinkpad with 16 mb edo ram built in and an extra 16mb chip installed. I am looking to put at least 32 mb more in, but wondering if it has to be edo also. Any ideas? I'm not sure if the extra chip is edo or not.

Thanks for any info.
 

AndyHui

Administrator Emeritus<br>Elite Member<br>AT FAQ M
Oct 9, 1999
13,141
17
81
Yes, the additional memory must be EDO, or even FPM (older than EDO). You cannot mix SDRAM and EDO.
 

PH0ENIX

Member
Nov 20, 2001
179
0
0
Yes, it must be EDO.

Even FPM I wouldn't attempt, because it has a lower latency - if you mix modules with different latency you should put the slower module in the first bank, so the machine can use all modules at the slower speed.

Because the existing 16mb EDO is onboard, chances are it'll attempt to use the additional memory @ 60ns - which FPM probably wont like too much ;)

Oh, and not to nitpick, but "You cannot mix SDRAM and EDO." is a bit ambiguos, because EDO is SDRAM.

A less confusing statement might be "you cannot mix ordinary PC66/100 memory with EDO"

I'd say the only way the existing additional chip would be anything other than EDO, is if it was proprietry FPM with a lower latency - like many HP omnibook systems use.

Good Luck!
 

Motero

Senior member
Jan 31, 2001
889
0
0
Is there an easy way to tell if it has 144 pins or 72 without counting them? Does this count include front and back or just one side of the chip?
 

Motero

Senior member
Jan 31, 2001
889
0
0
anyone? I'm thinking 72...just cause its small...just want to be sure before i buy a chip. thanks
 

BuckNaked

Diamond Member
Oct 9, 1999
4,211
0
76
Here is the info from IBM memory. I checked crucial and they don't offer a memory upgrade for that model, saying that it may not be available or may be propreitary. Good luck.

Dave