Article View: comp.sys.mac
Article #40469Re: Virtual, how many megs?
From: Shirley Kehr
Date: Thu, 06 Apr 1989 14:37
Date: Thu, 06 Apr 1989 14:37
44 lines
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2498 bytes
In article <6514@bsu-cs.UUCP> mithomas@bsu-cs.UUCP (Michael Thomas Niehaus) writes:
<In article <2615@osiris.sics.se>, ollef@osiris.sics.se (Olle Furberg) writes:
<> How many Mb (maximum) do I get with the Virtual-init on a MacIIx/SE30 ?
<> Someone told me that I can't get more than 8 Meg. Suppose I have 8 Meg
<> HardWare memory, is Virtual of any use?
<> If it is a limit for Virtual, is this a general limit for the 030-MMU?
<This has been discussed before: Currently, the Mac operating system
<limits you to only (and I choke on only) 8MB of memory.
I thought the question was about the Virtual init. I presumed that Olle
was either using A/UX or looking ahead to the future when the 8Mbyte
limit didn't exist.
I suspect the answer is that Virtual might not access more than 8 Mbytes
today, but that there is no reason for any limit as soon as it is usable
by the Mac. They already did a second version of the init for 030 machines
so they seem committed to keeping up. As to A/UX support, I suspect you'd
have to ask them.
Shirley Kehr
In the future,
>I would expect to see a rewrite of the OS to allow for up to 32MB, but
>right now it is not feasible. So, in general 8MB is the limit, period,
>for any of the 020 or 030 machines. (I believe that the reason for the
>8MB limit is that the ROM routines are mapped beginning right after this
>8MB ceiling.)
>
>Unless of course you use A/UX. I don't believe that it has this restriction,
>allowing up to 32MB of real memory. I remember someone recently posting a
>message saying that they were using 4MB SIMMs (a set of 4 of these) giving
>them 16 MB, all of which was usable by A/UX, but the Mac II he was using
>just ignored the upper 8MB. Note that this didn't produce any problems.
>
>-Michael
>
>
>
>--
>Michael Niehaus UUCP: <backbones>!{iuvax,pur-ee}!bsu-cs!mithomas
>Apple Student Rep ARPA: mithomas@bsu-cs.bsu.edu
>Ball State University AppleLink: ST0374 (from UUCP: st0374@applelink.apple.com)
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!elroy!orion.cf.uci.edu!uci-ics!zardoz!dhw68k!arcturus!felix!kehr From: kehr@felix.UUCP (Shirley Kehr) Newsgroups: comp.sys.mac Subject: Re: Virtual, how many megs? Message-ID: <90725@felix.UUCP> Date: 6 Apr 89 14:37:11 GMT References: <2615@osiris.sics.se> <6514@bsu-cs.UUCP> Sender: daemon@felix.UUCP Reply-To: kehr@felix.UUCP (Shirley Kehr) Organization: FileNet Corp., Costa Mesa, CA Lines: 44