Re: 6502 false references?

[tdixon@everest.acpl.lib.in.us (Tim Dixon)]

klipsch@ssvs.gsfc.nasa.gov (Colin Klipsch) wrote:

>To all--

<digital scissors applied>

>My question is: which 6502 instructions generate double references?  More
>specifically, which instructions will hit the speaker twice instead of
>once, when applied to the speaker I/O addresses?  I've looked in
>Leventhal's and Zak's 6502 books, but didn't find this information.
>(Perhaps I overlooked it...?)

>I appreciate any help you might offer on this...

It's all write instructions, isn't it?  As I recall (off the top of my
head so take it with a grain or two of salt), the 6502 architecture
strobed the address lines twice for write instructions.


A| Tim Dixon,  Systems Troubleshooter,  Allen Co Public Library
C|--------------------------------------------------------------------
P| 900 Webster St.  Fort Wayne, Indiana 46801   219-424-7241 x2309
L|--------------------------------------------------------------------

They let me plug my coffee maker into the mainframe UPS, but they
don't let me speak for them.