Path: utzoo!utgpu!jarvis.csri.toronto.edu!torsqnt!tmsoft!list-injector
From: root@nebulus.UUCP (Dennis S. Breckenridge)
Newsgroups: can.usrgroup
Subject: Re:  Is it the interleave?
Message-ID: 
Date: 28 Sep 89 05:47:00 GMT
Reply-To: root@nebulus.UUCP (Dennis S. Breckenridge)
Distribution: ont
Lines: 16


ST-506 interleave is recomended to be 3:1 unless you are running a 
Western Digital 1006-WA? or similar 1:1 controller. Most Diagnostic
software with these controllers are accurate to a point. To test the
controller out format it then run the PC Tech Journal Benchmarks 
If the disk test results are good at 2:1 leave it, otherwise format it
for 3:1 or 1:1. Re-test it. 
 Your interrupt problem is obvious. Com1 runs at a typical spl(6) level
and that is high. Disk runs at a lower level but also uses DMA which means
the cpu is put to sleep. Are you getting the idea. Modem is in xfer mode
... need a block of data ... disk is on wrong block or not cached ... put
new disk request up... uucp times out ... disk request complete ... uucp
still times out ... disk block is transfered ... interrupt is generated 
modem generates interrupt ... disk interrupt is suspended due to the high
priority of serial port. interupt is serviced and  modem now has data 
and everything is happy again. ignore typos and grammar... it is 2am