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Re: Olli working, help?

Subject: Re: Olli working, help?
From: Andreas Busse <>
Date: Wed, 25 Oct 1995 21:06:21 +0100
In-reply-to: <>

 > There is just one problem - some SIMM types return the same type code in
 > the register.  So you have to try if the RAM really exists by accessing it.
 > If you try to access non existing RAM you'll get a NMI exception which
 > transfers control to the boot ROM ...

Have you tried that? I doubt that it really works this way,
since neither the hardware nor the BIOS can detect the
difference between these SIMMs with identical IDs. The only
way to find out what size of memory is installed is to
access the last address of the expected memory area, and
if a write-read-verify cycle fails, fall back to the smaller
size. If the BIOS would get a NMI during this access, it 
couldn't determine the size either. Or have I missed something?


Andreas Busse                      |
Soft N Hard GbR                    | Phone: +49 2636-970105
Im Hufen Boden 16, D-53498 Waldorf | Fax:   +49 2636-970106

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