2FK8ALIN@UKANVAX.BITNET (04/27/87)
Date: Mon, 27 Apr 87 12:24 CST From: <2FK8ALIN@UKANVAX.BITNET> Subject: 6502 vs 68000 To: info-atari8@score.stanford.edu X-Original-To: info-atari8@score.stanford.edu, 2FK8ALINE In his message of 23 Apr 87 John Sangster writes that a 1.8 MHz 6502 might beat an 8.0 MHz 68000 in certain tasks. This is not true. It is true that the quickest 6502 instruction is only 2 clock cycles, but it is NOT true that the quickest 68000 instruction is 14. In fact, the fastest 68000 instruction is but 4 cycles long - the average instruction is around 12-14 cycles. Compare this to the 6502's AVERAGE of about 4-5 cycles per instruction (only CLC, INY, etc. take 2 cycles). At about 4 times slower than the 8.0 MHz 68000, NOTHING is faster on a 6502. I do agree that the 8 bit machines have many virtues, and I love my 6502 Atari 800, but the 68000 is much more powerful, even if more complex. One more point: the 6502 accesses memory every clock cycle, while the 68000 takes a full 4 to do so. This gives the 6502 a few advantages, but it still cannot outperform the 68000 unless the clock speeds are much closer to each other. -Eric Greene