DMA / programmed IO question

[Stefano Concina]

Hello, I am posting this since I don't seem to be able to get through anybody
decent at SCO-tech support (they say that a "senior analyst" will be calling
me tomorrow).
Has anyone tried the patch on page A43 of the 2.3.2 Xenix release notes ?
What it is supposed to do is switch the disk controller from DMA to programmed
IO. The patch is wrong since it refers to a variable in the kernel that does
not exist....
I wanted to try this out since I am only getting 400Kb/second off a WD1006SR2
controller, driving a Toshiba MK134 (66MB RLL). Under DOS I am getting close 
to 700KB/sec....
Does anybody out there have any suggestions as to how to squeeze more
performance out of this controller/drive ? BTW the system is a 386 @ 25MHz
with 2Mb of main memory, and the WD controller has all the jumpers in the 
standard factory configuration.

Thank you for your help !!!

Stefano Concina
stefano at sj.ate.slb.com
Stefano Concina
(uucp) ....!decwrl!spar!stefano
(arpa) stefano at spar-20.arpa