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From: David Eugene Dwiggins <dd2x+@andrew.cmu.edu>
Newsgroups: comp.os.386bsd.questions
Subject: FreeBSD reboots
Date: Fri,  3 Sep 1993 12:26:18 -0400
Organization: Fifth yr. senior, Electrical and Computer Engineering, Carnegie Mellon, Pittsburgh, PA
Lines: 28
Message-ID: <kgVr0eG00WB6BLPIIi@andrew.cmu.edu>
NNTP-Posting-Host: po4.andrew.cmu.edu

Here's the situation:

486-66 With the HiNT Pseudo-EISA (24 bit DMA) motherboard
BusLogic 742A (33MB/s mode)
20M RAM

When booting the kernel, everything went well.  But as soon as I started
accessing the floppies/hard drive, the machine died & rebooted.

I solved the problem by masking off the ram above 16M in CMOS. 
Everything is working now, but I'd like to be able to use the floppies
without the machine rebooting.

I'd like to think the problem is universal to all machines, but I'm
wondering if FreeBSD detects my machine is EISA based and thinks the DMA
controller is 32-bit.  (nope.  guess it's not really EISA.)

Anyway, is there double-buffering code in the floppy driver to handle
machines with over 16M RAM?

The machine is working great when I'm not using the floppy.  The
BusLogic uses bus-mastering, so the 24bit DMA isn't a problem for it.

Is over 16M RAM "supported/supposed to work" with any machine?

Thanks,

David