Trouble Installing GS/OS 6.0.1

[twillkickers]

Hello all! I just got a nice new 20SC external SCSI drive and connected it to my Sandwich II Card in the IIGS. The 20SC has been re-fitted with a 512 megabyte SCSI drive from IBM. My Sandwich II is in slot 1. I partitioned the HDD into two partitions using Apple II High Speed SCSI card utilities. However, when I try to install GS/OS, I get a message that says "Cannot INSTALL. Need approximately 823k more space." This doesn't make much sense to me, since my partitions on the drive are 32 MB each. What is going on? I appreciate your help!

 

[bibilit]

I had this kind of issue once, the hard drive was too big for the system, even with a partition on it, managed to find a smaller one to solve the issue.

Not saying this is the problem, but happened to me.

 

[twillkickers]

How big was the drive you ended up using? I switched to an 80mb drive and got the exact same error.

 

[bibilit]

40 mb IIRC, but 80 mb should be ok anyway, trouble probably elsewhere.

 

[NJRoadfan]

Create partitions that are slightly smaller than 32MB. I know earlier RamFAST SCSI cards had weird bugs with partitions that were the max 32MB, don't know about the Apple ones.

 

[twillkickers]

Tried 31MB and 30MB partitions, and got the same exact error. Any other possible causes?

 

[bibilit]

Any termination issue ??

 

[twillkickers]

Tried a million things and eventually guessed my way to victory. I turned off Direct Memory Access for the Sandwich II card by putting the no 1 dip switch in the open position. Any guesses as to why this worked? The only other card I have installed is Uethernet II.

 

[nglevin]

No RAM expansion card at all? Everything's running entirely on the logic board's fast RAM?

 

[twillkickers]

No, I do have an applied engineering ram card. Around 1mb.

 

[nglevin]

Some memory expansions are not DMA compatible. Or more accurately, the way DMA works on an Apple IIgs is funny, and when you're using modern cards to handle storage on the IIgs and they come with a DMA option, you frequently need hardware and software that accounts for it.

There's a couple of postings that explain the problem. Here's a good one; https://ultimateapple2.com/forums/forum/main-forum/8meg-memory-card-2gs/346-dma-compatibility?p=347#post347

The various GGLabs RAM expansions have some tricks to get DMA working to the degree it can. I've been happy since I switched to using one.

 

[twillkickers]

Thanks for the tips, I am going to try out the official apple RAM module I have at my parents' place later to see if my Applied Engineering GS-RAM is compatible with DMA. Keep in mind that it is just a little over 1MB of ram though.

Speaking of which, I tried to boot just using the logic board RAM, but my IIgs only has about 155k of logic board RAM. Is there any way to solder upgrade the logic board ram on my machine?

In addition, when I try to boot to the drive with DMA turned on and the Applied Engineering GS-RAM inserted, I get a "Fatal system error-> 0308" screen. Maybe that error will help explain the problem...

 

[nglevin]

It's an event queue error, which I figured out just by triaging between Danny Goodman's "The Apple IIgs Toolbox Revealed", and the list of IIgs error codes:

https://apple2.gs/downloads/TheAppleIIGSToolboxRevealed.pdf

http://apple2.org.za/gswv/a2zine/faqs/Csa2ERRLIST.html

Yes that's the same Danny Goodman who wrote HyperCard business software books and stackware for Activision back in the day.

The queue is stored in memory (...of course...) so it is by proxy a form of memory error.

Back when I was having this kind of trouble with RAM expansion cards and newer IIgs storage cards, I e-mailed the vendors of the storage card to ask what they knew about these configurations. It's possible that you just need to get a new RAM expansion card to use DMA.

...as for soldering RAM on the board, that's far beyond what I know. The ROM 03 boards had a full megabyte of fast RAM on the board. The ROM 01 boards tend to be more highly sought after despite that. My understanding is that a fair bit of early IIgs software had its own hacks to get around the performance bottlenecks of the IIgs, and many of them were based on strong assumptions around how the ROM 01 works.

 

[NJRoadfan]

Your picture is a bit blurry, but I already see the problem. The Rev A AE GS-RAM card is NOT DMA compatible. Only the Rev E GS-RAM is fully DMA compatible as per the RamFAST installation manual (I know its not an Apple card manual, but these DMA problems apply to ALL cards). You'll forego 512k of extra RAM, but the Apple 1MB card is fully DMA compatible. Applied Engineering did some really funky designs on their cards to get those oddball amounts and they tend to break DMA. My GS-RAM Plus (6MB card) has similar compatibility problems. Its DMA safe for the first 4MB, but the card won't work in a ROM 3 machine without a GAL swapped out!

 

[twillkickers]

I really appreciate the solution. Looks like I'll be getting a new RAM chip soon! I'll report back once I've installed it.

 

[twillkickers]

Just got my GGLABS RAMGS/4 in the mail, installed it, turned on DMA, and everything runs as it should! Thanks for all the advice from everyone. I'm happy to have learned something new.