9 Mar
2011
9 Mar
'11
5:26 a.m.
Christian Corti wrote:
On Mon, 7 Mar 2011, Tony Duell wrote:
I'd say no, microcode is software.
Maybe that depends on the complexity of the microcode sequencer and whether
the microcode itself is able to do loops and branches?
All the outside world sees is a hardware interface, though, so either way
I'd still class it as hardware from that point of view. As I mentioned to
Tony though, I'm really interested in CPUs that supported multiply/divide
"out of the box" - needing to change the microcode or add a math copro
don't count, even if once added they were transparent to the programmer.
cheers
Jules
*
mainframe, mini, micro; I'm not picky. I'm more interested in
building up a
picture of how widespread hardware support was, and the various
approaches
that designers used.
What do you mean by 'hardware' multiply and divide? A number of machines,
I suspect the 6809 is amongst them, had no particualrl hardware for
multiply or divide, but they did have multiply and maybe divide
instrucitons in the instruction setc. These instrucitons were implemented
by microcode using the normal registers and ALU. Does that count?