[TUHS] Old mainframe I/O speed (was: core)
dave at horsfall.org
Sat Jun 23 16:08:23 AEST 2018
On Thu, 21 Jun 2018, Arrigo Triulzi wrote:
>> for the microcode to customers. There were several hacks in there to
>> slow down the disk I/O so that it didn't outperform the model 30.
> Is this the origin of the lore on “the IBM slowdown device”?
If I remember my computer lore correctly, wasn't the difference between
the Cyber 72 and the 73 just a timing capacitor, if you knew which board?
And I still reckon that the olde 360/20 (I did see the console for one)
should never have been part of the 360 series;
* It had a HALT instruction!
* It had about half the instruction set.
* Half the number of registers, and width.
* Floating point? What's that?
Etc. A triumph of marketing over engineering...
-- Dave, who did his CompSci thesis on the 360...
More information about the TUHS