Re (2): [Oberon] PPP & multi-tasking/initialising

peter_easthope at peter_easthope at
Sat Feb 22 16:57:04 CET 2003


cg> It will be difficult for me to get this 
book [_The Oberon System_] in a hurry.

Ch. 15 is only 19 pages.  Provide an address 
and I'll mail a photocopy.

Pity that the older references haven't come
out on CD.

cg> "PPP design & debugging" James Carlson

Thanks.  I'll check the bookstore.

cg> 1. does S3 multitasking use an equal time slice for each task of the 
  'circular sequence' of tasks ?

No.  That requires multiple suspendable 
processes.  Quoting from page 158:
"Since tasks are not pre-empted by the 
system, it is essential that task handlers
do not seize control over extended periods
of time (the recommended period is less 
than 100 ms.)".

cg> 2. How could the Ctrl+<break> (TRAP 13  Keyboard interrupt)
    allow the 'hung state' of the PPP' to release'.

Question for Edgar or Pieter.

cg> 3. any other descriptions or pointers re. S3 multitasking.

Try to get Pieter Muller's thesis.  (Is 
it on line?)

cg> I believe that an understanding of S3 multi-tasking
is needed to understand the symptoms which I described.

If the problem stems from the indefinite 
timing of the S3 event loop, the best 
solution might be to use Aos.

Regards,      Peter E.

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