Re: What to do with slow Chip/ST RAM

[Michael van Elst <mlelstv%serpens.de@localhost>]

On Thu, Mar 19, 2009 at 08:44:13AM +0000, David Brownlee wrote:
> From:  <mlelstv%serpens.de@localhost>
> > That's why AmigaOS (finally) also kept track of MEMF_24BITDMA.

> Does NetBSD at least warn about such a problem SCSI controller?

It just handles them correctly. Available MEMF_24BITDMA memory
is used with the alloc_z2mem() function to allocate bounce buffers
where necessary.

The gtsc driver even knows about '25bit DMA' which is a special
construct for a SCSI+RAM-Card where the SCSI controller can
use DMA to the local RAM even when this is mapped outside the
Z-II address space.

Greetings,
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."