Software for IBM 36030
as part of doing some work for the disk engineering lab (building a crash proof operating system that could concurrently operate-test multiple testcells under development):
found an idiosyncracy built into controllers. the 3274s when they first came out were especially prone to hanging and needing to be re-iml'ed. it turns out that if you hit every device address on the 3274 in quick sequential succession with hdv-clrio combination ... you could force it to re'iml (under program control w-o requiring manual intervention and some person to go over and hit the button on the controller). so we found that most controllers would react that way.
also, the channel director was introduced with the 303x boxes.
Software for IBM 36030 was DOS360: Forty years 520
Rob Warnock This somewhat reminds me (not surprisingly, I guess, considering the genealogy) of the Honeywell H-200. I think I still remember some of the commands to start a job ..... Seems like there was...
the 370-158 was a microcoded engine that timeshared the processor between 370 operation and the channel operation (i.e. it had integrated channels like most of the entry and mid-range machines, both 360 and 370). for the 303x channel director ... they took the 370-158 engine ... slightly repackaged the box ... using just the integrated channel micrcode (and leaving out 370 microcode and the timesharing between the two function).
a 3031 was effectively a two-processor 158 smp ... one processor running dedicated integrated channel microcode ... and the processor running dedicate 370 microcode. a 3032 was effectively a repackaged 168-3 that operated with 303x channel director. a 3033 started out being the 168-3 wiring logic remapped to faster technology and using 303x channel director.
it also turned out that if you were to hit all channel addresses on a 303x channel director in quick succession with clrio ... it would also cause it to re-iml (under program control w-o requiring somebody to walk over and hit buttons).
misc. past m'code postings
for various topic drift ... other random past 3274 postings:
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