Subject: Re: Is ELC memory non-parity or parity?
To: Jesper Nilsson <dat92jni@ludat.lth.se>
From: Curt Sampson <cjs@portal.ca>
List: port-sparc
Date: 03/05/1997 07:45:38
On Wed, 5 Mar 1997, Jesper Nilsson wrote:

> The Sun hardware reference says that the SLC can not use the
> same 4MB simms that the ELC uses, but it also says that
> ELCs use _33_ bits instead of 32 or 36 which are the
> usual definitions.

According to the hardware FAQ, both machines uses 33-bit memory.
This is memory with one parity bit, instead of four, for every
32-bit word. If you look at the SIMMs themselves you'll see that
they have eight chips on the front, and one chip and three blank
solder pads on the back. These are usually usable as non-parity
RAM in other machines (such as PCs) but not as parity RAM.

There are evidenly some 4 MB SIMMs that the SLC and ELC can share.
There may be problems related to refresh timing or something that
prevent others being shared.

cjs

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