Article 163051 of comp.os.vms: (I hate having to follow up my own posts - one day I'll learn to proofread BEFORE I post!) greg@indiana.edu (Gregory Travis) writes: >I can't remember what a divide-by-zero did on the CPU hardware. I don't >recall there being any mechanism (until the later XJ ins OOps. I forgot to revise that. My feeble memory tells me that a divide-by-zero on the 6600 simply caused the CPU to halt. PPU 0 would detect that the CPU had halted and would actually look at the instructions and operands in the vicinity of the halt PC to determine if a divide by zero (as opposed to a program halt) caused the halt. >Most 6600 instructions typically took either 3 or 4 major cycles. Should be "3 or 4 MINOR cycles" (i.e. 300 to 400ns) Branches >took a little longer (branches were very expensive on the 6600). Thus >the 6600 was nominally about 3 million instructions per second (I earlier >wrote 1 mips). Typical real-world results with good functional parallelism were somewhere around 4-5 mips. greg -- greg greg@indiana.edu http://gtravis.ucs.indiana.edu/