[Info-vax] QIO Writes to a mailbox

[Bob Koehler]

In article <5afc6c93-099a-45d4-b2cb-b26a38c5598d at n38g2000yqm.googlegroups.com>, Steve Bainbridge <stephen_bainbridge at yahoo.co.uk> writes:
> 
> Hi,
> 
> This code was written several years ago and I've been dumped on to
> investigate and correct the issue we now very occasionally see. I'm
> aware of the obvious missing check on the IOSB, but I can't say with
> any certainty that this is causing the problem.

   Not checking the IOSB is _not_ causing the problem.  But you can't
   fix a problem until you know what it is, and checking the IOSB is
   how you find out what it is.