1 Aug
2004
1 Aug
'04
9:45 p.m.
On Mon, 2 Aug 2004, Hans B PUFAL wrote:
OK, I've sent this question to the IBM Haus of
History in Sindelfingen
in Germany. They have a working 650 so should be able to provide an
answer. I'll keep you informed.
I didn't think of doing that! Thanks!!
The periodic interrupt (50 or 60 times a second
depending on which side
of the pond you were) was most definitely available in 1964 on the IBM
System/360. At each tick, the hardware decremented a word in memory and
when it overflowed to zero, a program interrupt was invoked. The handler
would do whatever it needed and reset the memory word.
Earlier IBM machines also some form of this feature. On the 7094
modified for CTSS it was an IBM special feature.
Yes, from what I've been told, the 7090/7094 had a clock feature of some
sort.
--
Sellam Ismail Vintage Computer Festival
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