GVP 64pin SIMM pinout

[Zetr0]

Hello there forum chummies,

I am on the hunt for the GVP / Apple 64 Pin Memory socket Pin out / Data Sheet


I looking to building a small easy to make bridge card that will allow for 72pin SIMM variants.

From my research so far they need to be Square Memory Matrices SIMM type @ 60ns (1/4 or 16MB supported)

I just need the 64pin - pin out to make it happen anyone have a spare luscious linkie to share?

[keropi]

on aminet: Hack 72-pin SIMM to fit GVP cards

[Zetr0]

@keropi

Thanks buddy

you know whats strange though.... I actually downloaded this from programmers heaven.... it doesn't have two of the included pictures that have the 64pin SIMM pin-out..... weird me thinks.

thanks for the luscious linkie

[keropi]

so, was this what you were looking Z?

[Zetr0]

Yepo Amigo!

it has the pinouts i need

time to hack diddly hack hack hack!

(this time i am hacking the port... not the simm)


thanks muchly for the linkie

[keropi]

[coze]

before I sold my ultra precious 16 mb GVP SIMMs, I did take pinouts of them, and I just zoned them. as far as I can remember the only difference with the 4mb SIMMs were two extra address lines, a10, and a11, though I'm not sure.

[Zetr0]

thanks coze!

[Jope]

Originally Posted by Zetr0

Hello there forum chummies,

I am on the hunt for the GVP / Apple 64 Pin Memory socket Pin out / Data Sheet

As far as I know, they are not compatible between each other.. Both invented their own 32bit SIMM standard.

According to this http://www.applefritter.com/node/3712#comment-34218 Apple actually made theirs a bit more mac-only, the simms require co-operation from the memory controller to work.

[Zetr0]

@jope

indeed, my research leads me to believe that the memory cells are organized in a Narrow Matrix, as opposed to a Square or Wide.

Coupled to this is the way the fact that the memory chips on the SIMM is consulted as though there independent of the SIMM as a whole (totaly unlike 72pin SIMM technology)

Also as a mute point really, the 64pinn SIMM standard has no presence detect, four Write Enable Lines and one Output Enable Line where as 72Pin SIMM technology has (as you know my friend) 4 presence detect lines, only one Write Enable line and absolutely no Output Enable line to talk of!

At this point, I could easily design a 4 or 16mb ram module that would work in a 64pin GVP based product, however manufacturing might be a little tricky.

I believe you could make a small interface board using a few simple logic chips to essentially decode the incoming signals from the Apple SIMM and convert them to the 72pin SIMM standard, and obviously back again. however my logic isn't all that good lol...

I will keep at it me thinks.... it will tempt me now and then...