Re: 6502, 65816 = RISC ?

[lesherjt@vuse.vanderbilt.edu (Tilghman Lesher)]

Gilles Tschopp (gilles.tschopp@esis.vsnet.ch) wrote:
: Hello,

: I would like to thank to the people who have answered my 
: questions about the ROM04 and 65832.

: Now, I have a nice question. 

: For me, I consider the 6502 (and 65816) as RISC and not CISC. 
: The RISC is only a philosophy and not a technical way of 
: manufacturing CPU. I still have my Apple IIc and I always feel 
: that the 6502 is quicker than the 8086-4.77 (and even the 
: 8086-9.54 from my old Toshiba portable), and is comparable with 
: a 286-8 or 10.

There's a difference between how Apple and IBM rated their processors.
The difference is basically a factor of 4:  A 4 MHz IBM chip is roughly
equivalent to a 1 MHz 6502.

: Moreover, the 6502 has only five registers and can manage 
: directly the memory. So it has less opcodes to execute, compared 
: with the 8086, and can be considered as RISC.

Well, not really.  The 65xxx series processor never was complex,
so historically, it's naturally simple, and didn't need to be "reduced".

And a RISC processor usually has integer multiplication built-in as an
op-code (isn't this CISC in a RISC?), and the 65xxx doesn't have
multiplication, except as performed through complex series of ADC's
and ASL's.

Tilghman