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Thread: Apple IIgs 8MB RAM problem

  1. #11

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    Quote Originally Posted by Eudimorphodon View Post
    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.)
    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.....
    -- Lee
    If you get super-bored, try muh crappy YouTube channel: Old Computer Fun!
    Looking to Buy/Trade For (non-working is fine): TRS-80 Model II,12,16,6000, Mac IIci hard drive sled and one bottom rubber foot, Hercules card + mono monitor (preferably IBM 5151), Multisync VGA CRTs, 040 or 601 card for Mac IIci, Decent NuBus video card, Commodore PC(286+), PC-era Tandy stuff, Aesthetic Old Serial Terminals, Amiga 2000 or 3000UX

  2. #12
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    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).
    What I collect: 68K/Early PPC Mac, DOS/Win 3.1 era machines, Amiga/ST, C64/128
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  3. #13

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    Quote Originally Posted by george View Post
    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.
    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.

  4. #14

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    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.

  5. #15

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    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.
    -- Lee
    If you get super-bored, try muh crappy YouTube channel: Old Computer Fun!
    Looking to Buy/Trade For (non-working is fine): TRS-80 Model II,12,16,6000, Mac IIci hard drive sled and one bottom rubber foot, Hercules card + mono monitor (preferably IBM 5151), Multisync VGA CRTs, 040 or 601 card for Mac IIci, Decent NuBus video card, Commodore PC(286+), PC-era Tandy stuff, Aesthetic Old Serial Terminals, Amiga 2000 or 3000UX

  6. #16

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    Quote Originally Posted by bladamson View Post
    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.
    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.

  7. Default

    Quote Originally Posted by george View Post
    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.

    Sounds reminiscent of Applied Engineering, a lot of their quality control left a bit to be desired also.
    --------------------------------------------------------------------------------------------
    The Lower Planes BBS Ports 22/23 telnet or SSH
    Pineapple Home of the Hardware Database
    Australian BBS list old style BBS registry listing.

  8. #18

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    Quote Originally Posted by Anthony Adverse View Post
    Sounds reminiscent of Applied Engineering, a lot of their quality control left a bit to be desired also.
    Sorry, but these are Universe apart AE are superb. You are comparing dedicated professionals and a hobbyist...

  9. #19

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    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.
    -- Lee
    If you get super-bored, try muh crappy YouTube channel: Old Computer Fun!
    Looking to Buy/Trade For (non-working is fine): TRS-80 Model II,12,16,6000, Mac IIci hard drive sled and one bottom rubber foot, Hercules card + mono monitor (preferably IBM 5151), Multisync VGA CRTs, 040 or 601 card for Mac IIci, Decent NuBus video card, Commodore PC(286+), PC-era Tandy stuff, Aesthetic Old Serial Terminals, Amiga 2000 or 3000UX

  10. Default

    Quote Originally Posted by george View Post
    Sorry, but these are Universe apart AE are superb. You are comparing dedicated professionals and a hobbyist...
    Ok, you go with that I have seen a lot of DUD AE equipment, maybe they sent it all to Australia. :P
    --------------------------------------------------------------------------------------------
    The Lower Planes BBS Ports 22/23 telnet or SSH
    Pineapple Home of the Hardware Database
    Australian BBS list old style BBS registry listing.

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