Mask all Interrupts and then Interrupt
JArchibald at aol.com
JArchibald at aol.com
Thu May 25 00:56:12 UTC 2000
=> 5/24/00 7:51:45 PM EDT, tim at sumeru.stanford.edu =>
<< Strange OpCodes: MII: Mask all Interrupts and then Interrupt >>
Tim--
In the ancient (and strange) world of early System/360 development and
marketing, there was very little (as in 'nothing') to run on the available
machines to convince any conceivable buyer that these machines did anything.
A reputed facility (details must be sketchy here, to protect reputations) was
developed known informally as "The Demonstration Compiler". It has such
memorable instructions as:
I: Read cards repeatedly.
II: Print. <basically whatever was in memory starting at address 0, in
hex>
III: Spin tapes rapidly. <i.e., forwards and backwards>
along with control instructions to generate timed loops of such things.
This last instruction was quite important. 7090 users knew that machines that
were working hard used their tapes a lot (earliest S/360 models didn't have
the disk packs -- and potential buyers would have been unfamiliar with them
anyways).
To a better world!
Cheers,
Jerry.
____________________________
Jerry L. Archibald
systemObjectivesIncorporated
____________________________
More information about the Squeak-dev
mailing list
|