ifarqhar@sunb.mqcc.mq.oz.au (Ian Farquhar) (01/18/91)
I am posting this article for a friend. I have not seen the problem in question, and am describing it from the description she gave me. My friend has a 25MHz A3000 equipped with 16M of RAM. With this setup, AMax installed with 128K ROMS refuses to run. As a test, the memory was reduced to 9M, and with this configuration AMax ran successfully. Nothing else was changed. Does anyone have any ideas why this should be so? My initial thoughs were that the Mac ROMs may be unable to handle 16M of RAM, but I thought that I would ask the net if anyone else has any ideas. -- Ian Farquhar Phone : 61 2 805-9400 Office of Computing Services Fax : 61 2 805-7433 Macquarie University NSW 2109 Also : 61 2 805-7420 Australia EMail : ifarqhar@suna.mqcc.mq.oz.au
jet@karazm.math.uh.edu ("J. Eric Townsend") (01/19/91)
In article <1114@macuni.mqcc.mq.oz> ifarqhar@sunb.mqcc.mq.oz.au (Ian Farquhar) writes: >My friend has a 25MHz A3000 equipped with 16M of RAM. With this setup, >AMax installed with 128K ROMS refuses to run. As a test, the memory was >reduced to 9M, and with this configuration AMax ran successfully. Your guess is probably correct: I don't think any of the non-MacII macs can handle more than 8Mb of ram. Many (most?) can only be expanded to 2.5 or 4Mb. I don't think you can put more than 8Mb in a stock MacII. But yes, your initial assumption was correct. The 128K mac roms blew up when they saw that much memory. -- J. Eric Townsend Internet: jet@uh.edu Bitnet: jet@UHOU Systems Mangler - UH Dept. of Mathematics - (713) 749-2120 Motorola skates on Intel's head!
ottmar@ajberl.UUCP (Ottmar Roehrig) (01/23/91)
>In article <1114@macuni.mqcc.mq.oz> ifarqhar@sunb.mqcc.mq.oz.au (Ian Farquhar) writes: >My friend has a 25MHz A3000 equipped with 16M of RAM. With this setup, >AMax installed with 128K ROMS refuses to run. As a test, the memory was >reduced to 9M, and with this configuration AMax ran successfully. >Nothing else was changed. > >Does anyone have any ideas why this should be so? My initial thoughs >were that the Mac ROMs may be unable to handle 16M of RAM, but I thought >that I would ask the net if anyone else has any ideas. At our site we have an A3000 equipped with 16MegF/2MegC and A-Max II runs perfectly on this machine. But be aware, that the SE-ROMS are not able to handle more than 4 MByte (at least, as far a I now) and the rest of RAM should be dedicated to the RAM-Disk! Ciao,Ottmar = AtelierRoehrig, Ottmar Roehrig, Hamburg | UUCP: ...!cbmvax!cbmehq!cbmger!ajberl!ottmar - "42" (Deep Thought, some million years ago)
daveh@cbmvax.commodore.com (Dave Haynie) (01/25/91)
In article <1114@macuni.mqcc.mq.oz> ifarqhar@sunb.mqcc.mq.oz.au (Ian Farquhar) writes: >My friend has a 25MHz A3000 equipped with 16M of RAM. With this setup, >AMax installed with 128K ROMS refuses to run. As a test, the memory was >reduced to 9M, and with this configuration AMax ran successfully. >Nothing else was changed. >Does anyone have any ideas why this should be so? I suspect there's just a little bit of magic here at work. The current Mac operating system can only handle 24 bit addressing, basically what you get with a 68000. Mac IIs running the Mac OS use the MMU to make everything wrap to 24 bits, and I imagine the AMAX II does something similar on the A3000. Internal A3000 Fast memory is mapped from $07000000-$07ffffff on that 16MB machine, well out of the 24 bit space used by the 68000 hardware. With some MMU tables, you could translate some of this Fast memory into 24 bit space, but certainly not all of it, since there are I/O regions that must be taken out of the total 16MB space 24 bit addressing gives you. Presumably if Apple releases their System 7.0, which reportedly fixes this problem in the Mac OS (though not necessarily all Mac applications), AND System 7.0 learns to deal with non-contiguous memory pools (like AmigaOS does), AND AMAX gets upgraded to do whatever is necessary to live under System 7.0, than you may get all 16MB free under AMAX. >Ian Farquhar Phone : 61 2 805-9400 -- Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy "What works for me might work for you" -Jimmy Buffett