John Hall wrote: > I think you'll find that the JCB is only updated when a task switch > occurs... > > When a TRAP#n is executed, the PC and SP are saved on the > supervisor stack, hence WL's earlier comment...
Oops! PC and SR, of course :-) In supervisor mode, the job's SP is in the USP... > > Now I can forsee there might be a problem if the calling job is in > > SV mode when it makes the Open call, as it would first have to > > exit SV mode before it could set up jobs, open channels and > > things, but it must sooner or later exit that mode, and the > > execution will procede as described. > > This is wrong, for the above reason. Correction. This would work, so long as the job's PC could be found on the supervisor stack by the driver code... John _______________________________________________ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
