View Full Version : Closed 64 pin simms (GVP ?)

15th April 2008, 20:01
I have in my possession a number of 64 pin simms. These were salvaged from a server used in the print industry some years ago. (It was a 386, to give you some idea)

I don't know whether these simms will work with GVP hardware, as I've heard conflicting stories, and anyway, I have nothing to test them on. I don't even know what size they are.

If someone, preferably UK based, has a piece of GVP hardware that takes this type of simm, and would be willing to test one of them for me, then I'm sure that we could come to some arrangement. :) (i.e. They get to keep the one they test. Free, Gratis, and for nothing.)

NOTE: I am an Electrical Technician, and I am 99% certain that these will work in GVP hardware. Many people have said that GVP made their own simms, but (at the time that GVP were producing stuff that uses these) there were only about 4 companies in the world that produced memory chips/sticks. The investment in plant would have been too much for a company the size of GVP. Hence, I strongly believe that the 64 pin simms that GVP sold were simply rebranded proprietary simms.
I also suspect that GVP did a pretty good job of brainwashing people into thinking that they could only use "their" simms. (Wouldn't you ?, if you were selling something on at a huge markup ?)

Cheers, fraggle.

7th May 2008, 18:39
I just bought some of these from the US because I couldn't find any. What size are they? I am after 16MB ones. Will you do sale or return if they don't work?

7th May 2008, 19:48
if you both post some hires pictures, not only would i have some tasty hardware pr0n, be we could also compare chips and layout.

oh... did i mention the hardware pr0n ? :D

8th May 2008, 11:03
@ Skote: If you're in the UK, let me know, then I can post one to you for testing. I have no idea what size they are, BTW.

@Zetr0: I'll post some photos soon. Kinda busy right now.

8th May 2008, 18:54
OK, Hardware pr0n for Zetr0. ;)

Find it here: http://www.imagehosting.com/show.php/17 ... m.jpg.html (http://www.imagehosting.com/show.php/1742074_64PinSimm.jpg.html)

8th May 2008, 18:59

thanks muchly for the hardware pr0n :)

I shall work out how ram is on the cards. and the configuration :D

all i need now is a picture (as nice as the one posted) where i can ascertain both the chips on it and the configuration of the matrix :D

8th May 2008, 19:11
just got into a coffee and and a bit of tech spec..... ahhh such is life :D


with thanks to Pascal "P-chan" Janin. from "GVPRam 32bit Hack" available from Aminet

Sidenote: There is rumor saying that these Chipack 3240 would have a
cheaper Macintosh equivalent: SIMMs for Mac II FX. After
investigation, I found out that these Apple SIMMs had the same 64 pins
connector indeed, but their size is 1MB 8 bits each only, instead of
4MB 32 bits for a GVP. Therefore they are useless.

so I am thinking that IF these are indeed 32bit wide matrix access then WHOOT baby!

8th May 2008, 19:51
Oh well some bad, and good news.

the Chips wont be compatible with the GVP i am afraid to say, the access time is too slow (80ns) requires 60ns or better,
also these sticks are 8MB in size which makes them incompatible with the GVP accelerators as they can only string up 4 or 16MB sticks. this is down to its memory controller (or bad interpretation of one) it has an explicit matrix.

let me try an explain and if i get it wrong well ... go Google it yourself :p lol

for those that wanna read a longer explanation

a memory stick is a collection of modules, each module is organized as a group of cells, each cell is a certain size, 4bit / 8bit /16 bit / 32 bit / 64bit and so on and so on...

so from this we can create a memory map thats, SQUARE (like a map), FAT (like a rectangle) or NARROW (like a door),

from this the controller accesses the matrix using Columns and Rows (similar to a spread sheet) now in some controllers there is probing of the module, either by design or by fault and the matrix of that module is discovered and used, some controllers require an explicit memory matrix shape (like the GVP)

8th May 2008, 21:07
OMG Zetr0, hardcore hardware pr0n and explicit memory!!!
:shock: :oops:
(Merlin goes off to have a cold shower)


8th May 2008, 21:14
Zeets, you da man!!!! :mrgreen:

15th May 2008, 20:11
Just seen this update about pictures. Let me see if I can rustle some up....

15th May 2008, 20:13
cheers Skote :)

15th May 2008, 20:18
OK. Here are my two GVP SIMMS. The labelled one is the newly made one I got from SoftHut. The "naked" labelless one is the GVP original. Both are 4MB:

15th May 2008, 20:32
Thanks very much skote,

that really solves a lot of things

Alas my friend, there is no simple hack to use these apple 8mb 64pin simms, i was hoping that there would be but alas there is not... :(

the Pin Out is just too different. If one was inclined to use some 30AWG wire and solder about 60 connections lol

I will look into seeing the cost of fabbing some bank sticks that would be compatible with the GVP, but i would need to actually get some and dismantle i dont think anyone is going to let me lose with their precious 16mb gvp simm with a hot air re-work station LOL, However if some has 16mb gvp simms i would love a super hires photo of them (back and front)

15th May 2008, 20:40
'Tis a shame. Mind you, I think my 10MB total will do me for now. I've just got a working PCMCIA network card and KS3.1 for the 1200. I'm waiting for OS3.5 (in the post to me) with bated breath.... 8)