Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!ucbvax!gnh-starport.cts.com!whitewolf From: whitewolf@gnh-starport.cts.com (Tae Song) Newsgroups: comp.sys.apple2 Subject: Re: OctoRAM and DMA Message-ID: Date: 20 Apr 91 02:36:30 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 17 X-Unparsable-Date: Fri Apr 19 91 at 07:42:11 (EDT) ------------------------------ Stuff Deleted -------------------------------- |I also have an OctoRAM card. I have 2-1MB parts in it and have no problem |running with my RamFAST with DMA enabled and my TWGS. My understanding is |that no matter how many slots for ram your card has, the Apple IIGS will only |do DMA to the first 4 rows (SIMMs) for a maximum of 4 meg. If you use 256k |parts in the Octoram, that means that only the 1st Meg would be DMA (not good) |If you use 1MB parts, only the 1st 4MB would be DMA. The apple IIGS CANNOT |do DMA above 4MB of ram no matter what ram card you have. Having more than |4MB in your Octoram should work fine, just realize that properly built |hardware will not even try to do DMA to any memory above 4MB. Oh no. DMA is limited to the first 4MB, not 4 first row. It doesn't matter if you use 256K or 1, 2 or 4MB SIMMs. It's just 4MB. INET: whitewolf@gnh-starport.cts.com UUCP: crash!gnh-starport!whitewolf ARPA: crash!gnh-starport!whitewolf@nosc.mil