On 9/08/2023 8:10 am, Phillip Stevens wrote:
> On Tuesday, 8 August 2023 at 22:54:05 UTC+10, dxforth wrote:
>> On 8/08/2023 2:11 pm, Phillip Stevens wrote:
>>> Of course this is only going to work if your target is actually 8085.
>> A pity Intel didn't seriously look at an extended instruction set.
> A bit OT but since you asked. The enhancements Intel made to the 8085, and then decided not to support, made the 8085 almost perfect imho. Undocumented stack access using DE instructions is much faster than IX/IY in the z80, and the 16 bit rotations really accelerated math (given no hardware multiply).
> Using these enhancements, and a “native” C compiler, the 8085 actually beats the z80 in some of our z88dk benchmarks.
> So one excellent code table (256) of instructions is a pretty nice design.
I assumed any undoc instructions would be either side-effects or planned but
broken in some way. From what you say this doesn't appear to be the case here.
Sounds like it was an executive decision to leave them out. Unfortunately the
result is the same - software that uses undoc instructions have a certain odour
>> Why Faggin left?
> Wasn’t there, but I guess it is easier to get rich working for yourself. 😊
> Something he perhaps wouldn’t have achieved at Intel.
Though for creative folk leaving tends to be more about frustration. For Intel
execs it would have been about where best to invest their money.