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andrel wrote:
> Neither the 6510 nor the Z80 had a floating point processor. Floating
> point was in software.
That's true. But assuming we want, say, a normal "double precision"
floating point number, how many clock cycles would you estimate it takes
to operation on? A dozen? A hundred?
> Both had a variable instruction set that took a variable amount of
> cycles to execute and therefor the number of instruction processed
> depended on the program and especially on the addressing modes used.
I thought this was true for *all* processors?
(Of course, unlike modern processors, cache effects are not present.)
> although the MIPS rate is not very well defined, on average it
> may be in the order of 1/3rd of the clock speed for 65xx and 1/5th-1/4th
> for Z80.
Sounds roughly right. (For the 65xx anyway - I have a manual somewhere
that lists all the opcodes and addressing modes...)
So that gives us, very approximately,
- C64 = 1.0 MHz / 3 = 0.333 MIPS.
- ZX Spectrum = 3.5 MHz / 4 = 0.875 MIPS.
So each is giving us probably a few hundred thousand complete opcodes
executed every second.
Now, anybody have any clue "how big" the numbers are for less ancient CPUs?
--
http://blog.orphi.me.uk/
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