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- Path: sparky!uunet!cis.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!rutgers!cbmvax!mks
- From: mks@cbmvax.commodore.com (Michael Sinz)
- Newsgroups: comp.sys.amiga.misc
- Subject: Re: 1023k Chip RAM
- Message-ID: <33664@cbmvax.commodore.com>
- Date: 24 Jul 92 19:26:08 GMT
- References: <1992Jul16.133630.13514@syma.sussex.ac.uk>
- Reply-To: mks@cbmvax.commodore.com (Michael Sinz)
- Organization: Commodore, West Chester, PA
- Lines: 23
-
- mpue2@syma.sussex.ac.uk (James E. Talbut) writes:
- >Last night I stuck some more memory in my A2000, and afterwards I
- >started looking at the nice big numbers that 'avail' was giving me.
- >For fast RAM I had exactly 5 * 1024 * 1024 bytes,
- >but for Chip RAM I had only 1 * 1023 * 1024 bytes.
- > ^^^^
- >
- >What has happened to the other K that I should have ?
-
- Well the exception vectors (256 - 4byte vectors) need to go somewhere
- and on 68000 machines they *MUST* be at location 0 and up. So the first
- 1K of memory is used by the OS and never made available.
-
- (Plus there is 32 bytes per memory block that can never be made available
- due to the fact that the memory header had to go somewhere...)
-
- /----------------------------------------------------------------------\
- | /// Michael Sinz - Senior Amiga Systems Engineer |
- | /// Operating System Development Group |
- | /// BIX: msinz UUNET: mks@cbmvax.commodore.com |
- |\\\/// "A master's secrets are only as good as the |
- | \XX/ master's ability to explain them to others" - Michael Sinz |
- \----------------------------------------------------------------------/
-