ccplumb@watmath.UUCP (10/08/87)
In article <21@lzaz.ATT.COM> bds@lzaz.ATT.COM (BRUCE SZABLAK) writes: >One major point about RISC that I haven't seen mentioned, is that a simpler >instruction set implies that a LOT less silicon is devoted to micro-code. >This silicon can be used for other things such as a large number of >registers or, in the Transputers case, support of high speed serial >communication lines. One reason RISC's execute faster is that access to >on chip memory (e.g. registers) is faster than accessing off chip registers. >Also, in some RISCs the instruction set is implemented using >logic as opposed to micro-code which is usually faster too. I'd just like to point out that almost *none* of this applies to the Transputer. It's got *lots* of microcode (to do multiprocessing and message passing, etc.), and no registers in the VAX/68000/most RISC chips sense. Some people (myself included) would argue that if the chip is microcoded, it isn't RISC. I certainly don't think the Transputer is a RISC chip. It's stripped down in some ways, but those ways aren't the ones "RISC" chips. use. Based on the power of what's built into microcode, it's a CISC. -- -Colin Plumb (watmath!ccplumb) Zippy says: Catsup and Mustard all over the place! It's the Human Hamburger!