Re: OctoRAM, High Speed SCSI and Zip GS

[David.Empson@bbs.actrix.gen.nz]

In article <1993Jan12.021932.25578@nuscc.nus.sg> ltchean@iss.nus.sg (Lim Thye Chean) writes:
> 
> Hello, I am heving a little difficulty here.
> 
> I am buying a High Speed SCSI card from my friend, to replace my Rev. C card,
> but encountered some problem. This is my configuration:
> 
> ROM 1 GS, OctoRAM 2MB (256K simms), Zip GS (9MHz/32K), Rev.C SCSI, two
> harddisks (40MB Western Digital, 120MB Quantum), and a AI sound card.

The problem is that the OctoRAM is not DMA-compatible if you are
using 8 SIMMs.  The High-speed SCSI Card's firmware (and the GS/OS
drivers) will prevent DMA accesses above 4 megabytes, so using 8 MB in
an OctoRAM might be safe (I've never tried it, but from my circuit
analysis it should work).

However, 2 MB with 8 SIMMs is not supported.  Get some 1 MB SIMMs!
-- 
David Empson

Internet: David.Empson@bbs.actrix.gen.nz    EMPSON_D@kosmos.wcc.govt.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand