Subject: Re: prob with ether setupo
To: Bakul Shah <>
From: Daniel Carosone <>
List: current-users
Date: 01/22/1995 09:23:50
Bakul Shah writes:
 > For what its worth, I did have data corruption problems when
 > I was using 16Meg memory, SMC Elite (but not ultra) & AHA-
 > 1542B.  It disappeared when I reduced memroy to 12Meg.  I
 > swapped memory around and ran extensive memory tests and
 > think the memory is fine.  My guess is the problem is
 > related to L2 cache of my noname OPTi MB + AHA + may be the
 > SMC Elite.  I didn't pursue it after that but if someone
 > knows why and how to fix it, I'd sure like to know and get
 > my 4Meg of memory back.

Did you get any messages from the aha driver like this?

Dec 31 01:14:04 anarres /netbsd: aha0: DMA beyond end of ISA

The ISA bus can only address 16Mb of memory. Some motherboard/bios
setups will remap some of the memory between 640k-1M up to the top of
memory, so that it can be used. My motherboard was doing this, and
with 16Mb of memory in the machine, the remapped memory was beyond
what an ISA bus DMA master could reach.

I found a BIOS setup option to disable this (normally useful) feature,
and have had no trouble since.