4 ms·
None of the 8-bit CPUs had that, but you can get pretty far with left- and right-shift (which is the same as multiplication and division by 2), which allows to
by flohofwoe 3y ago
None of the 8-bit CPUs had that, but you can get pretty far with left- and right-shift (which is the same as multiplication and division by 2), which allows to compose multiplication and division by constants quite easily (it's a bit more trouble and usually too slow for a universal runtime mul/div, but one simply tried to avoid that, or use precomputed lookup-tables instead).
- zabzonk 3y agonot division, but the 6809 8-bit processor did have a MUL(tiply) instruction.
- flohofwoe 3y agoI stand corrected and TIL :) That's pretty awesome actually, pity that the 6809 wasn't more popular in the home computer era (but looking at the price compared to the Z80 or even 6502 it's understandable - $37 versus $9 for Z80 and $6 for the 6502 in 1980 according to Wikipedia: https://en.wikipedia.org/wiki/Motorola_6809 https://en.wikipedia.org/wiki/Motorola_6809).
- zabzonk 3y agoi wasn't aware of the price difference, and at the time i owned a 6809-based system - a dragon32 (a sort of UK re-branded version of the tandy colco). i wasn't fussed about the MUL instruction, but i simply loved all of the addressing modes that thing had.
- dboreham 3y agoI worked in embedded systems design through this era. I don't remember ever hearing of a design using one 8-bit cpu vs another due to chip cost. Those Wikipedia numbers also seem suspect.