[Oberon] Oberon loop and FPGA VGA

Frans-Pieter Vonck fp at vonck.nl
Thu Feb 28 00:25:06 CET 2013

> The Ceres workstation had a special key which interrupted the system and
> returned control to Oberon.Loop.  It was detected in the keyboard
> interrupt handler, Input.KBINT, and causes a Trap(24).  See Project Oberon
> Ch. 9.2, pp.260-261 (PDF p.208).
This was not what I meant.
On page 33, Project Oberon"[..] unsafe background tasks are removed from
the ring of ready tasks before reactivation, and are installed again only
after successful return. Consequently unsafe tasks are eliminated
automatically after failing. This is an effective precaution against
cascades of repeated failures."

I find that intriguing - what is an unsafe background task?

The question that comes to my mind - how did they verify the operating
system. The answer I expect to get from behind the Alps is - "by elegant
Or is there something else? Can it be found in the brains of Olga or Horla ?


*I have three Bernina's from the sixties and seventies and the they still
sew perfect stitches. Prices of these machines were in the sixties 700
guilders. Back then the average income was 500 guilders a month. The
average income in the Netherlands nowadays is 33.000 euro. That means, if
you equal guilders with euros, a Bernina sewing machine now would have
cost 3850 euro. Imagine, buying something that is more than a month worth
of salery? In the sixties, a domestic machine. Now, that must be..... a
You can find a sixties Bernina's on the secondhand market here for around
150 euro. And prices are rising.

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