jhs@MITRE-BEDFORD.ARPA (05/08/87)
Thanks to Eric Greene for his more careful comparison of 6502 and 68000 instruction timing. I bow to his greater knowledge of the 68000 (and probably the 6502 also) and agree that his data proves that the best a 6502 could hope to do is come within 1/1.34 or about 74% of the speed of a 68000 with the respective clock speeds used in the 800XL and the ST (1.76 MHz and 8 MHz respectively). Had I noticed that there are 68000 instructions that execute in only 4 clock cycles, and looked as closely as Eric has at which instructions are that quick, I would not have suggested that the 6502 might win on some benchmarks. I hope the exercise in comparing the two processors has been enlightening to others as well as to me. Of course, we still have the ANTIC and POKEY to contend with in the 8-bit Ataris. I won't contest the fact that the ST is a more powerful machine overall, but I will expect the 8-bitters to continue to hold their own in animated graphics and sound generation, at least until the much-awaited Blitter (and maybe a sound chip with more voices) arrives in the ST line. Considering the price difference and the age of the 8-bit technology, Atari deserves great credit for the performance they got from the 8-bit architecture, lo those many years ago! -John Sangster / jhs@mitre-bedford.arpa