Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!yale!cmcl2!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn)
Newsgroups: comp.sys.apple2
Subject: Re: DMA, Octoram
Message-ID: <13956@smoke.BRL.MIL>
Date: 28 Sep 90 16:38:10 GMT
References: <0093D2C8A67760C0.00000110@dcs.simpact.com>
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 10

In article <0093D2C8A67760C0.00000110@dcs.simpact.com> scottr@gnh-applesauce.cts.com (Scott Rothstein) writes:
>Um, how many megs does the OctoRAM run??? Forgot. Anyway, as a rule, 6 or 8 meg
>cards aren't DMA compatible.

The OctoRAM can be configured with 1, 2, 4, or 8 SIMMs (all 256K or all 1M).
While the upper "half" of the card is not compatible with the IIGS's DMA,
if the only DMA device you're using is Apple's High-Speed SCSI Card then
it's not a big problem, since that card reverts to programmed-I/O mode for
transfers involving addresses above 4MB.  I found that mine seems more
reliable if I allocate the upper 4MB for a RAM disk.