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Apple IIgs 8MB RAM problem

D

dittman

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Joined
Jul 31, 2017
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Plano, TX
I have a IIgs with a TransWarp GS and CFFA3000. When I install a GGLABS RAMGS/8 GS/OS locks up during boot. I don't have any problems with the card removed.

I've run the ROM diags in the IIgs and the TWGS diags with and without the RAMGS/8 installed and they all pass.

Is this a compatibility issue with 8MB cards in general, the RAMGS/8 specifically, or is there something else I should check?
 
Alphasite said:
I have a IIgs with a TransWarp GS and CFFA3000. When I install a GGLABS RAMGS/8 GS/OS locks up during boot. I don't have any problems with the card removed.

I've run the ROM diags in the IIgs and the TWGS diags with and without the RAMGS/8 installed and they all pass.

Is this a compatibility issue with 8MB cards in general, the RAMGS/8 specifically, or is there something else I should check?
Click to expand...

https://www.applefritter.com/content/trouble-gglabs-ramgs8-rom3-machine
 
The card is buggy. It doesn't work at all in my ROM3 machine. It does *appear* to work in my ROM1 machine, although others have said it is unstable for them even in ROM1 boxen.

I switched to a ByteBoosters 8Mb card, and it works flawlessly in my ROM3 box.
 
Alphasite said:
I bought a ByteBoosters 8MB card and it's working great.

Thanks again!
Click to expand...
Did you get a refund for the buggy GGLABS card? Their apple2 SCSI card appears to be buggy too. Shame for GGLABS "Designed and assembled in USA with all new components." advertisement in ebay, obviously the latter is not a key to error free and working products. Their publications full of colorful fancy screen captures from expensive state-of-the-art oscilloscopes/analyzers and technical explanations for the dazzled impressed breathless public ;) But with the 8M //GS RAM card the well known superior German quality wins.
 
Last edited:
george said:
Did you get a refund for the buggy GGLABS card? Their apple2 SCSI card appears to be buggy too. Shame for GGLABS "Designed and assembled in USA with all new components." advertisement in ebay, obviously the latter is not a key to error free and working products. Their publications full of colorful fancy screen captures from expensive state-of-the-art oscilloscopes/analyzers and technical explanations for the dazzled impressed breathless public ;) But with the 8M //GS RAM card the well known superior German quality wins.
Click to expand...

Oh is their SCSI card buggy too? D: How so?

I read that it was a copy of the Apple card, so I bought the kit with the board, ROM, and PALs. But I haven't assembled it yet.

It does appear to be different in the way that it supplies SCSI termination power, but I figured that was to get around needing NLA components other than the scsi controller chip itself.
 
I have the GGlabs 4MB card that takes a single 30 pin SIMM and, knock on wood, I haven't seen any problems with it. But a 4MB 30 pin SIMM is *almost* directly electrically compatible with the GS's RAM slot so there's significantly less to need to get right than there is with an 8MB card. (The IIgs was really designed to support only 4MB, 8MB cards require some logic tricksiness to synthesize a D22 address line. Presumably that's what GGlabs isn't getting quite right.)
 
Eudimorphodon said:
I have the GGlabs 4MB card that takes a single 30 pin SIMM and, knock on wood, I haven't seen any problems with it. But a 4MB 30 pin SIMM is *almost* directly electrically compatible with the GS's RAM slot so there's significantly less to need to get right than there is with an 8MB card. (The IIgs was really designed to support only 4MB, 8MB cards require some logic tricksiness to synthesize a D22 address line. Presumably that's what GGlabs isn't getting quite right.)
Click to expand...

The funny thing is, it *appears* to work fine in my ROM1 box. But the ROM3 box crashes within 10 seconds.

I was thinking maybe since the ROM3 boards have more built-in ram, the card was shadowing some of the system ram and they were glitching each other out or something, I dunno.....
 
From my understanding the IIgs as built can do 8MB of ROM and 8MB of RAM. The first 4MB of RAM uses build in DMA and refresh from the RAM controller, any RAM over that does not use DMA and you need to add chips to refresh it (engineering required). ROM 1 machines have 256KB of RAM on the motherboard, ROM 3 have 1.25MB on the motherboard. So on a ROM 3 machine when you attach an 8MB RAM card some of it is unusable and generally the RAM that falls outside of DMA is best used for s RAM Disk.

A ROM 3 with the Apple 1MB RAM card is pretty much good for anything outside of GS/OS 6 and GS/OS is only nice to use if you have an accelerator (and 4MB RAM).
 
george said:
Did you get a refund for the buggy GGLABS card? Their apple2 SCSI card appears to be buggy too. Shame for GGLABS "Designed and assembled in USA with all new components." advertisement in ebay, obviously the latter is not a key to error free and working products. Their publications full of colorful fancy screen captures from expensive state-of-the-art oscilloscopes/analyzers and technical explanations for the dazzled impressed breathless public ;) But with the 8M //GS RAM card the well known superior German quality wins.
Click to expand...

I haven't contacted them about that. I bought it nearly two years ago and used it with a ROM 1 system without the TWGS or CFFA3000 and didn't have any problems, then put the old IIgs away. Then I got a ROM 3 board and installed it along with the TWGS, CFFA3000, and GGLABs card and installed GS/OS. I had the lockups and then ran the diags. As I'm relatively new to the IIgs before I started tearing everything apart I thought I'd check here first.
 
I apologize to revive an old thread, but I'd like to set the record straight.

All GGLABS RAMGS products should work on both ROM1 and ROM3.
All cards are tested on one of my ROM3 systems before shipping.

If you are having issues, please contact me and I will replace/repair your card.

I don't exclude the possibility of incompatibility with some specific configurations. I am happy to offer free hardware to anyone who helps identify and solve a design issue.

For the technically inclined:
1- Memory configurations
The maximum amount of fast RAM that a Apple IIgs will recognize is 8MB (including the fast RAM on the motherboard).
This means the expansion is 8064K on a ROM1 (8192K-128K) and 7168K on a ROM3.

2-DMA
DMA is possible only to the internal fast RAM and the first 4MB of expansion RAM (this is a apple IIgs hardware limitation).
Expansion cards that are not aware of this can crash a machine with 8MB expansion.

3-A22 generation
For people handy with a solder iron there is simple a way to disable A22 generation on the RAMGS/8 to isolate the problem.
Please contact me for details.
 
My inoperable IIgs configuration was an empty ROM3 board, no expansions cards, one 3.5 drive attached, a monitor on the RGB port, standard ADB keyboard and mouse. The system crashes within 10 seconds of startup every time, usually (but not always) with screen garbage. My voltage levels read fine, and I've tried two different PSUs just in case.

The same ROM3 board works with every other RAM card I've tried in it (including a modern 8mb card from another maker, a fully populated Apple card, and an AE card), and your card seems to work fine in both of my ROM1 boards. I don't have any extra ROM3 boards to test it in, but since all the other RAM cards seem to work, it makes me suspicious.

I posted a message on your forum about it, but it was still not approved after several days, so I quit checking for a response and bought a different maker's card. I see now that there was a response two weeks later, but I'd stopped checking back by that time.

If you want to send me a replacement and have me return this one, I'll try a different card in the machine and see what happens. But like I said, all three of the other memory cards I've tried have worked fine in the machine. I am reasonably handy with a soldering iron, and I have a 'scope, if you need a little help sussing out what is going on, but my work load is extremely heavy at the moment so I don't know if I have time for a whole lot of in-depth testing. But I am willing to help out a bit if I can.
 
bladamson said:
My inoperable IIgs configuration was an empty ROM3 board, no expansions cards, one 3.5 drive attached, a monitor on the RGB port, standard ADB keyboard and mouse. The system crashes within 10 seconds of startup every time, usually (but not always) with screen garbage. My voltage levels read fine, and I've tried two different PSUs just in case.

The same ROM3 board works with every other RAM card I've tried in it (including a modern 8mb card from another maker, a fully populated Apple card, and an AE card), and your card seems to work fine in both of my ROM1 boards. I don't have any extra ROM3 boards to test it in, but since all the other RAM cards seem to work, it makes me suspicious.

I posted a message on your forum about it, but it was still not approved after several days, so I quit checking for a response and bought a different maker's card. I see now that there was a response two weeks later, but I'd stopped checking back by that time.

If you want to send me a replacement and have me return this one, I'll try a different card in the machine and see what happens. But like I said, all three of the other memory cards I've tried have worked fine in the machine. I am reasonably handy with a soldering iron, and I have a 'scope, if you need a little help sussing out what is going on, but my work load is extremely heavy at the moment so I don't know if I have time for a whole lot of in-depth testing. But I am willing to help out a bit if I can.
Click to expand...

I apologize for taking so long to reply on the gglabs forums. All first posts are moderated to limit spam.
I really appreciate you offer for help. I will send you a PM with the return instructions.
 
george said:
Did you get a refund for the buggy GGLABS card? Their apple2 SCSI card appears to be buggy too. Shame for GGLABS "Designed and assembled in USA with all new components." advertisement in ebay, obviously the latter is not a key to error free and working products. Their publications full of colorful fancy screen captures from expensive state-of-the-art oscilloscopes/analyzers and technical explanations for the dazzled impressed breathless public ;) But with the 8M //GS RAM card the well known superior German quality wins.
Click to expand...


Sounds reminiscent of Applied Engineering, a lot of their quality control left a bit to be desired also.
 
GGLabs sent me a replacement card to try, but I haven't gotten a chance yet. -- Or rather, I seem to always get distracted chasing other shiny things and squirrels instead (one of my many personality faults).

I'll let y'all know how it turns out when I get 'round to it. Although I had a little trouble getting hold of him initially, it seems like he is trying hard to make things right, so please don't be too hard on him.
 
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