Re: 8MB GS RAM cards

[pubpc1@library.ucla.edu]

Rubywand wrote:
> Mitchell Spector writes ...
> >>
>      A problem is only going to arise *IF* your using devices which use
> DMA (Direct Memory Access - a process in which the device can interact
> directly with memory, bypassing the processor) and you have 5 megabytes
> or more (4 MB is the DMA limit) present in the expansion slot. Such
> devices can include SCSI or IDE controllers, video capture boards, etc.
> The RamFAST SCSI does tricks to get around it, combined with certain
> designed memory boards, but it doesn't always work and risky IMHO. (some
> have report success, others have reported failure).
> <<
>  ....
>      Thanks for the information; however, it leaves us with a lot of
> questions. For one thing, what happens if you try to boot a System 5.0.4
> diskette on a ROM-03 with one of the two current 8MB boards? And, of
> course, the Accelerator + DMA business is a mine field of non
> information.
> 
>      Users should not need to blow an extra $40-$50 to experiment with
> 8MB and, then, discover their setups won't work. Once again, why don't
> the 8MB Expansion RAM card makers just say what works with what and how
> well?

Good idea.  I might be of help, since I have a decked out GS with 8MB.

My system is a 13.75MHz Zip GS with an 8MB Sirius RAM card.  It has
greater than 1GB of total storage via an Apple High Speed (DMA) SCSI
card.  It is a ROM 3.

With my SCSI card, DMA must be turned off to use 8MB without problems.
I borrowed a RamFAST rev. D card to try and it _does_ work with an
8MB card without problems.

However, at 13.75MHz, DMA just shaves a second or two off booting,
so the loss of DMA is not that bug a deal (ie. 10 seconds with DMA
on and 11 seconds with DMA off, if I remember correctly).

I have used the Sirius with both System 5.0.4 and System 6 (6.0
and 6.0.1).  In all cases and with all GS/OS software, all 8MB
were recognized without a hitch.  RAM disk setup on System 6.0.1
is also not a problem.  I have never tried to set a RAM disk in
System 5.0.4.

The 8MB has no problems at all with my 13.75MHz Zip GS.

All my software is enhanced.  Now I can convert full page
scanned documents (like sample exams and and answer keys) off
the school's web site , convert them using Prism, and print
them out using Platinum Paint.

8MB is really needed and useful if you want to make large
full screen movies with an Apple IIGS.

Go to

http://ground.isca.uiowa.edu/apple2/apple16/Hypermedia/Hypercard/

and download Su27demo.shk, my movie of a jet fighter taking
off from an airfield.  You need 8MB to make it and 8MB to view
it.  It is a full screen 320x200 grayscales movie with a
synchronized sound track.

-Scott G.