On Mon, 30 Aug 1999, M. Meschederu wrote:

> Have you checked, whether these SIMMS are suitable for the SE/30.
> Back in the days this machine was constructed, 4mb SIMMS sounded
> like sciene fiction :-)
> With my old SE/30 (32mb/1g/NetBSD 1.31) I had a similar problem after
> putting in 4 4mb SIMMs. Apparently the SE/30 doesn't like all 4MB SIMMs,
> mine had three Chips. These Chips worked in newer Macs like Q700 and IIci.
> I traded the three chip SIMMs for eight chip SIMMs and everything worhed fine.

Sounds like you got some 16 MB chips configured as 4MBx4. Each chip
generation can add complications.

The Mac II and IIx had real problems with 4MB chips (either 4MBx1 or
1MBx4). It seems the 4MB chips had a self-test mode which was engaged by
sending a certain memory signalling sequence (doing a refresh with r/w
set for write). Because the motherboard didn't know about it, it would
accidentally send these chips into self-test mode, which would crash the
machine. :-(

Take care,

Bill