special 64 pin 1 or 4 MB 60 ns GVP SIMMs

[rkauer]

countzero wrote:
if somebody has the eagle library for a 72 pin SIMM PCB, I believe we can derive a 64 pin GVP compatible from it.

Of course having the PCB produced will cost a lot (probably 50-100$ for the first prototype, 5$ ish for the boards after, add to that the trouble of unsoldering re-soldering ram chips from 72 pin SIMMs)

 If the problem is ressolder the chips, why not leave as-is?

 Simply make that aminet hack properly in PCB, with a SIMM socket to easy the job.

[countzero]

I doubt it will fit in any accelerator with the SIMM socket.

[rkauer]

countzero wrote:
I doubt it will fit in any accelerator with the SIMM socket.

 Probably you're right. So another approaching: make the hack in PCB, without the SIMM socket and solder (yes, solder!) the "equivalent" SIMM on the PCB in a parallel way (one "board" in contact with the other).

 That way we can avoid the mess of another socket (with the tilted board) and with only a "longer" SIMM. :idea:

[countzero]

LOL I'm not sure this is easier than desoldering and resoldering RAM chips

anyway, primary problem is we don't have an eagle layout for 64 pin SIMM. Without that there's not much point in this discussion ...

[motrucker]

I just ran across two 68 pin SIMMs (non-GVP) that actually work fine on my G-Force 040! They are only 4Mb SIMMs, but better than nothing. I should mention that this two SIMMs out of about 100 that I tried! They have no markings at all on them.

[countzero]

are you sure they are non gvp ? many gvp simms I saw didn't have any markings too.

btw, its 64 pin.

[Fraggle1]

Hi,
I have a number of 64 pin simms, but I have no way of testing them to (a) see whether they work in GVP hardware, and (b) find out what size they are.

If anyone is willing to test them, and then report their findings back to me, I would be much obliged.

Cheers, fraggle.

[hardlink]

motrucker wrote:
I just ran across two 68 pin SIMMs (non-GVP) that actually work fine on my G-Force 040! They are only 4Mb SIMMs, but better than nothing. I should mention that this two SIMMs out of about 100 that I tried!

I'm impressed you are gutsy enought to plug in 100 different  ramdom old parts into a GVP accelerator and turn it on!  :-o

[motrucker]

countzero wrote:
are you sure they are non gvp ? many gvp simms I saw didn't have any markings too.

btw, its 64 pin.

Don't ask me why I typed 68. Some times typing, my brain and fingers don't seem to be on the same page. But, now I am not sure they aren't GVP. I thought they were all maked as such.

[rkauer]

countzero wrote:
LOL I'm not sure this is easier than desoldering and resoldering RAM chips

anyway, primary problem is we don't have an eagle layout for 64 pin SIMM. Without that there's not much point in this discussion ...

 I think this is not a problem. GVP SIMM have the very same "step" as any 72 pin SIMM.

 And using the Aminet hack make the things a little bit easier.

 Sorry if I not help too much in the "GVP SIMM quest", I'm busy making another cool Amiga gear. The ppl who are in EAB know what I mean...;-)