Re: Does an enhanced //e _ALWAYS_ have 80 col. support?

[Andy McFadden <fadden@fadden.com>]

Michael J. Mahon <mjmahon@aol.com> wrote:
>>I just now tried a very simple sound loop on a real IIgs.  There was no
>>difference for "LDA $C030" vs. "STA $C030".

> Just for the record, consider that a store absolute takes 4 cycles,
> three to read the instruction and one to write the target address--so
> there's no time for an extra access.
> 
> The indexed forms take a cycle to add the index and present
> the (non-page crossing) address to the bus, which, since read
> data arrives late in the cycle, allows the indexed loads to
> complete on the fourth cycle.

Also tested on a real IIgs: LDA $C030,Y makes noise, STA $C030,Y doesn't.

-- 
Send mail to fadden@fadden.com (Andy McFadden) - http://www.fadden.com/
CD-Recordable FAQ - http://www.cdrfaq.org/
CiderPress Apple II archive utility for Windows - http://www.faddensoft.com/
Fight Internet Spam - http://spam.abuse.net/spam/ & http://spamcop.net/