64-Pin 4MB SIMMs for Apple Display Card 8*24 GC

[jasa1063]

The best deal on eBay were these two, but those are listed for an Amiga. Does anyone know if these would work? One is parity the other is non-parity. The other question is could they be used together on the video card?

4MB 64Pin AST Commodore Amiga Fast Page Non-Parity FPM MEMORY 70NS Rare SIMM 4x8 | eBay

Find many great new & used options and get the best deals for 4MB 64Pin AST Commodore Amiga Fast Page Non-Parity FPM MEMORY 70NS Rare SIMM 4x8 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Pardon Our Interruption...

 

[Unknown_K]

They are not for Macs.

 

[jasa1063]

They are not for Macs.

Thanks!

 

[The Salami Boss]

They are not for Macs.

Strictly speaking, the Apple Display Card 8-24 is not a Mac.
But, yes, you need RAM SIMMs compatible with the Macintosh IIfx. You might get lucky on a listing for "LaserWriter SIMMs" but sometimes these are too slow.

but also sometimes not. /shrug

Good luck, these seem uncommon/expensive.

 

[Powerbase]

I believe the GC is fixed at its on board 2MB of VRAM. The extra memory is only for use in GWORLD applications and doesnt expand the VRAM.

Didnt someone make some IIfx RAM for sale? I thought I saw some third party ones recently.

 

[jasa1063]

I found a lot of 4 x 4MB 60ns IIfx memory. I can use the other two as spares. I intend to use the video card in a Mac IIci running System 7.1. I have read that System 7.5.x is not compatible, so I should be Ok with this setup.

 

[jeremywork]

I'm not sure of the basis for the "same as used by the IIfx" anecdote because my 8•24 GC refuses all of the RAM my IIfx happily boots with. I either get no chime/no image, death chime, or outright refusal to power on as if shorted. I eventually got lucky enough on eBay based simply on visual approximation. All of the 64-pin RAM I've seen installed on GWORLD cards is low profile and comprised of four horizontally mounted DRAM packages on each side with central gaps in their pins. Ideally I would've found 80ns to match the onboard, but these two 1MB @100ns are detected in the control panel and haven't caused any noticeable misbehavior.

 

[Coloruser]

LEM specifies the GWorld DRam upgrade as being the same as the Mac IIfx ram. However, Apple’s own documentation lists Part Number M0505LL/A as being unique to the GC. if being the same as fx memory, they would have stated that (or maybe not).

In a third party repair manual it is stated that either specific Apple ram or third party ram will work.

 

[slomacuser]

Interesting that so many different RAM modules were used for GWorld like Rasterops used standard 30 pin RAM for GWorld on accelerator board ..

 

[hyperneogeo]

The IIFX ram is not compatible with the Gworld area. I've tried 1MB sims, 4MB sims, 16MB sims. None of them will turn on with them in. It's like they are shorting it.

 

[Unknown_K]

Check the sockets for stray metal.

 

[jeremywork]

Mine act the same way. SIMMs in the photo above work perfectly, and ones from the IIfx mainboard act electrically incompatible. Some prevent power on completely and others let power blip on momentarily, or cause a death chime.

 

[jasa1063]

I also found out that they do not work. No harm to the card or my IIci, but obviously there is a lot of misinformation about this online. I will just keep on the lookout for the proper 64-Pin SIMMs. No luck finding any right now.

 

[testdriver]

is there a source?

 

[Siliconinsider]

I am now making the GWORLD RAM. At the moment the 1MB SIMMs do work and I will have them available very soon.
Looking at the documentation is is also possible to get 4MB versions, but as of now I can only get them to be recognised as 1MB so I may need more work.

 

[olePigeon]

@Siliconinsider Ooooo! I need to get on my eBay selling, cuz I'll need two sets of 4MB SIMMs.

Anyone know if the 8•24 GC was unique? Or did other video cards with RAM slots use the same RAM? Or were they smart and used non-proprietary RAM?

 

[Unknown_K]

Try the 4MB SIMMs in every other slot (just 2 SIMMs).

 

[Siliconinsider]

GWORLD RAM was used in other cards, I have these two.
I have made an adapter to put GWORLD RAM in my SIMMCHECK, but the 4MB SIMM is seen as a 1MB, so I have to check my design or what could cause the extra address line from being used. I think Apple created proprietary RAM at a time where 30-pin SIMM was the standard but they needed a small 32-bit wide module with a very low profile and small footprint form factor. That standard was then used by other NUBUS card vendors, but it has remained a very niche thing.

PS: I have never seen original 4MB modules, only 1MB.

 

[Siliconinsider]

A quick message for all those interested in the GWORLD RAM, I have a limited availability at $49 for a pair shipped. You can send me a DM to proceed!

 

[jeremywork]

I followed an old tip from @Unknown_K and played the Truevision card lottery, which landed me one with 4x4MB installed. Here's four shots of one of the modules:


@Siliconinsider, hopefully something visible there can help resolve the addressing issue, otherwise pm me and I can arrange to loan/sacrifice you the set, so long as some functional replacement can eventually be derived.