Kindly give the comments interleaved with your quoted message below a look. Dick -----Original Message----- From: Sellam Ismail <dastar(a)ncal.verio.com> To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> Date: Saturday, April 17, 1999 2:45 AM Subject: Re: z80 timing... 6502 timing Rules are a problem, aren't they? Rom Well . . . There's the problem . . . first of all, the code's got to be executable on something everyone has got available, or it's got to be simulated on a simulator everyone has available, else there'll be a limit on interest right away . . . Then, shouldn't there be some consideration of the coding/debugging time involved? I'd lean in favor of a PC-compatible simulator. That makes the computation of actual execution time straightforward. . . and, of course, it's got to run the code on a "real" processor, not just a putative "we could build . . ." sort of thing, right? . . . well, maybe . . . Then there's the question about WHICH 6502 to use. Given a listing, it's easy enough to compute how long it takes the code to run, but which instruction set? What about undocumented features? Both these processors were famous for those. Of course, there doesn't have to be a limitation, i.e. one could consider ALL available cores. I'd propose it be a significant problem, but one which is well-defined, i.e. algorithms are published, hence the problem solution is well-defined, and I'd propose further that the same algorithm be used so we compare "apples with apples." As for the processor core, well, it's also got to be one everybody's got available, yet it wants to be one which WAS available in 1982. That might include the Synertek, MOS, and MAYBE the Rockwell core. We can't just say 65C02, because it was buillt in several conflicting versions. What about the Z-80 core? Whose? Which one? Speed, of course, should be "limited" to whatever was available in 1982. That certainly includes the Synertek (MOS Technology-comptible)"4MHz" 6502C (always worked fine at 5 MHz by then), as well as the Zilog Z-80B (6-MHz). Was the 8MHz part out in 1982? what Whereas this might be "cute" it is very limiting, in that it has to be a graphics-capable environment available with both processors. It should not "fall" conveniently for either processor, so the graphics array should be large, and, AFAIK there's no such system for either processor. What should be done, here? Should we build a board? How do we measure how fast it's going? Remember, the hardware environment has to be more or less the same for both processors. dastar(a)siconic.com ---