Lmst

#CVAX

Bob Supnik breaks the CVAX to make COBOL run faster:

#DEC #Digital #DigitalEquipmentCorporation #VAX #CVAX #COBOL #ComputerArchitecture #ComputerHistory #ComputingHistory #ComputerHistoryMuseum #CHM #BobSupnik

these small VAXs are so successful, the software group comes in with a request. They say, “You know, we think we could actually make COBOL work just as fast on these machines as on the big ones with all their fancy instructions if you just give us a few more instructions. And not even decimal instructions, just give us a few more of the character string instructions.” So, | do some trial coding. And it was yeah, yeah. It's-- it looks good. So, in like the last six weeks before tape out of the second pass, | insert these instructions in the microcode, do the verification, send it out in the field. | broke the machine. | had overlooked a sneak path where when they're interrupted and something particularly peculiar happens in the interrupt pack up process and, as a result, the interrupt never happens, and you're supposed to resume, the instruction goes haywire. So, | have now personally set the project back three months. And it's like all right, time to retire from microcoding. Time to let somebody else do this. But it’s still out in time.

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