26 Apr
2006
26 Apr
'06
10:13 p.m.
Chuck Guzis wrote:
But the Z80 timings are very different than an 808[05].
Sure, if you are writing an assembler, text editor, etc. this
isn't really important. But, if you are trying to catch
timing pulses off an RF front end or implementing tight
delay loops (e.g., generating sound), you don't want to
suddenly discover that each of the paths through your
code are nolonger what you thought they would be.
(counting T states... blech! something I hope never to have to
do again!)
On 4/19/2006 at 11:34 PM Roy J. Tellason wrote:
[actually, the attribution should have been mine...]
> But a Z80
*won't* run 808[05] code.
Well, a Z80 will run 8085 code that limits itself to 8080 instructions.
But the 8085 has two documented instructions (RIM SIM) that the 8080
doesn't have--and a few more "undocumented" instructions (nonetheless used
by many embedded programs) that neither the 8080 nor the Z80 has. Initially I thought that the Rabbit was a good
idea--until I started to
program it. What did you do with (insert a list of instructions)? And an
interesting bug or two. Feh.
It was a stupid idea, IMO. Designed to lock people into their
device AND toolchain (neither of which seem worthy of much
attention).
Can you spell ARM?