On Fri, 18 Oct 2002, Jeremy Fowler wrote: > Seriously, RISC or Reduced Instruction Set Computer has fewer core > instructions. CISC or Complex Instruction Set Computer has all kinds of > instructions built into the processor that can be used by software If I understand this correctly, RISC processors encourage accumulator arithmetic. I found programming with just a few instructions was much simpler and faster than using all kinds of whiz bang logic train extensions on a CISC chip. The 6502 processor was a joy to use, because the instructions were simple. I would carry this habit of using few instructions with a CISC Z80 and find out that my programs would run faster. Why? Because the accumulator instructions on the Z80 didn't have byte prefixes that chewed up extra clock cycles. And the 6502 was designed from the beginning to not have extra logic loading down the core bus. The Z80 seemed to have too many logic trees chained from each other inside, requiring extra clock cycles to do anything. A compare with a Z80 would require several clock cycles versus one. Even though my 6502 ran at 2MHz, not 6MHz, the RISC 6502 ran faster. Less tools to program with may seem more difficult, but it was much more elegant. I only had to worry about the accumulator. The Z80 gave me so many choices, these tools could be scattered in a big mess throughout my code. This would make RISC 6502 code look like a clean, tidy shop with minimal stuff laying around to get tangled in the machines. When I programmed using minimalist techniques on the CISC Z80, my code would be less complicated, fewer bugs, and a joy to read. And it ran faster too. It made all those fancy instructions look like a salesman pushed all that junk on me. Who needed a cheese cutter when a knife would do for everything? The RISC kitchen was clean and simple. The accumulator for everything. Wipe clean when done. CISC had so much hardware to keep clean, things could get complicated fast and let the roaches play. And roaches led to rats. And rats led to cats. And my system would become a dog. With rabies, foaming at the mouth. So I like RISC. Its the swiss army knife of processors. Moral of the story: keep it short and sweet.