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From: jms@tardis.Tymnet.COM (Joe Smith)
Newsgroups: comp.sys.amiga.hardware,comp.sys.amiga
Subject: Re: Is 9 megs + AT Bridgeboard possible?
Summary: 128K chews up 4M of address space.
Keywords: A2286, 1-meg Agnus, 8-meg RAM, C00000
Message-ID: <942@tardis.Tymnet.COM>
Date: 23 Feb 90 09:42:58 GMT
References: <931@tardis.Tymnet.COM> <9663@cbmvax.commodore.com>
Reply-To: jms@tardis.Tymnet.COM (Joe Smith)
Organization: BT Tymnet, San Jose, CA
Lines: 26

In article <9663@cbmvax.commodore.com> daveh@cbmvax.cbm.commodore.com (Dave Haynie) writes:
>In article <931@tardis.Tymnet.COM> jms@tardis.Tymnet.COM (Joe Smith) writes:
>>is it possible to have 1-meg of CHIP RAM, 8-megs of fast RAM, and run
>>the BridgeBoard at $C00000, all at the same time?
>
>No, the Bridge Board memory will always be autoconfigured.  
>Second thing is, only 128K of Bridge Board memory is shared between the Bridge
>and the Amiga Bus, so you'd be wasting a great deal of effort for only a
>little extra memory.

I would not call 4 megabytes "only a little memory".

I am refering to the instructions on the A2058, which say that if you have a
fully populated board with 8 megabytes of expansion RAM and want to run a 
Bridge Board, you have to change the jumper so that the memory board uses
only 4 megabytes.  Several hundred dollars of memory chips suddenly made
unuseable.

That's what bugs me the most about the current implementation of the
Bridge Board plus Commodore memory boards.  The interaction of the two
wastes a lot of the address space.
-- 
Joe Smith (408)922-6220 | SMTP: jms@tardis.tymnet.com or jms@gemini.tymnet.com
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