Re: Ram

[andrep@balboa.eng.uci.edu (Andre Prellwitz)]

In article <1993Jul16.161741.9853@actrix.gen.nz> dempson@swell.actrix.gen.nz 
(David Empson) writes:
  [edited]
>> Has anyone Actually put a full 16 meg of ram on the IIgs?
>
>I doubt it.  The IIgs hardware (FPI) and memory manager only support
>fast RAM in banks $00 through $7F (8 megabytes).

There are //e's with >1Mb.  The GS could do this as well, but it'd be slow.

>It may be possible to patch the memory manager to support banks $80
>through $DF and $E2 through $EF, but I think there would be major
>hardware problems, and software may be making assumptions about valid
>bank numbers.  Banks $F0 and up are reserved for ROM (and used by
>some ROMDISK products).

I like the idea of virtual RAM using the interrupt line on the Aux Mem slot
in the GS.  When a (nonexistant as yet) RAM card 'sees' access to banks 
$e0-$ff, it reads from a hard drive.  VRAM was supposedly a feature of the
Snow DSP board that was never finished, although it used the processor to
sense reads to invalid RAM locations.  But, without bank switching techniques,
the GS will only be able to access 8Mb max. 

>> I run everything off of ram the drives and hard drive are just abit
>> slow to access...
>
>Easy solution here: get a RamFast SCSI card and/or a faster hard drive.
>
>My SyQuest drive and Apple High Speed SCSI card is much faster than
>RAM5.  Even my old slow Rodime hard drive is of comparable speed to a
>RAM disk.

What about the /RAM5 driver for GS/OS that supposedly speeds things up by a
factor of five or so?

Just a few thoughts for today....

---
The University of CA, Irvine doesn't agree with me  |  DM, F242, SP, NIN, U96