low-end vaxen and unix

Ken Wellsch kcwellsc at math.uwaterloo.ca
Sat Jan 30 08:07:36 AEST 1999

On a KA410 (VAXstation 2000 etc.) the MFM controller and the NCR 5380
both do DMA to a shared 16Kb private memory buffer.  You then have to
pull your data out into the regular VAXen memory.  I believe the Lance
chip (ethernet) is the only DMA to main memory capable device.

-- Ken

> [...]  There are however issues in that the hard disk
> interface and the SCSI chip use the same DMA channel and it would cause
> some performance degrdation. [...]
> Allison

Received: (from major at localhost)
	by minnie.cs.adfa.edu.au (8.9.1/8.9.1) id JAA17998
	for pups-liszt; Sat, 30 Jan 1999 09:36:06 +1100 (EST)

More information about the TUHS mailing list