Subject: Re: DMA ISA
To: Robert Niles <>
From: David Brownlee <>
List: port-i386
Date: 09/05/1996 17:55:59
> 24MB RAM
> Tried: 1542 controller for SCSI  HD

	Bingo - thats the problem.
	isa DMA is limited to the first 16Mb, so the 154x controller
	wont work in stock netbsd when you put more than 16mb in...

	Solutions - any of:

	    a) Pull 8Mb out to take you down to 16Mb

	    b) Do a, then pull down Juergen Hannken-Illjes's bounce buffer
	       patch to get NetBSD to work with 154x & >16Mb.
	       ( Applies to
	       1.2BETA or various earlier releases & runs fine.

	    c) Run OpenBSD, FreeBSD or some other system which supports
	       bounce buffers.

                   David/abs             (

.---- I've been too drunk to love ----.--- I've been too drunk to remember -.
|          Too drunk to care          |     The hell of the night before    |
|  Looked like death, felt like Hell  |    I've been drinking myself blind  |
`------ Been the worse for wear ------'--- And still I'll drink some more --'

On Thu, 5 Sep 1996, Robert Niles wrote:

> Last night my HD went down so I tried to configure a SCSI 2GB HD
> for use with NetBSD. When creating a new file system for the drive
> I received errors to the effect that DMA was too large for ISA.
> I couldn't get around that problem. Next I tried to bring up
> two IDE HDs It would recognize the first, but not the second. I have
> no idea why, because both drives are definately good.
> I have:
> Pentium 66
> 24MB RAM
> Tried: 1542 controller for SCSI  HD
> Robert