[HECnet] Re: Weird microcode bug in the 11/60 CPU

From: "bob" <bob(a)jfcl.com> To: "The Hobbyist DECnet mailing list" <hecnet(a)lists.dfupdate.se> Sent: Monday, February 7, 2022 6:16:29 PM Subject: [HECnet] Re: Weird microcode bug in the 11/60 CPU

... and the KL had double precision integer math instructions (DADD, DSUB, DMUL, DDIV) as well as double word integer MOVEs, so you could get 72 bit integer arithmetic without needing to deal directly with the carry flag anyway. I can't remember about the KI - I think it had DMOVE, but not any of the arithmetic instructions. As a practical matter the PC flags were not very useful to the average user mode programmer. And JFCL, with no flag bit specified, was the traditional NOP. I believe on a KL something like TRNN was actually faster to execute, but by then nobody was willing to switch. Bob _______________________________________________ HECnet mailing list -- hecnet(a)lists.dfupdate.se To unsubscribe send an email to hecnet-leave(a)lists.dfupdate.se