19 Aug
2001
19 Aug
'01
9:29 a.m.
> unused_zp = $02
> stx unused_zp
> ldy unused_zp
Let me see if I understand this. I have 2 registers on
the same chip.
Presumably a chip with data paths between at least some of the registers.
But to transfer data from one of them to another of them, I have to write
it out to external memeory, and then use a second instruction to load it
back in. And they're 2 byte instructions, right.
So that's at least 6 memory cycles (2 to fetch the opcodes, 2 to fetch
:
Heck, I've spent much of my life admiring designs
where there are fast
data paths between just about every section, and even designing machines
like that. And where said data paths are in use whenever possible (look
at the PDP11/45 CPU schematics and microcode flows for a good, simple,
example of what I mean). And you expect me to like the above...
You clipped the part where I said ;-), Tony :-P
--
----------------------------- personal page: http://www.armory.com/~spectre/ --
Cameron Kaiser, Point Loma Nazarene University * ckaiser(a)stockholm.ptloma.edu
-- If your happiness depends on anyone else, you've got a problem. -- R. Bach -