Re: A86: Flags
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Re: A86: Flags
On Wed, 27 May 1998 16:48:10 -0500 David Phillips <electrum@tfs.net>
writes:
>
>I decided to my first real dissassembly of the rom. If this info is
>anywhere else (I'm sure it is, please point me to it):
>
>-IY+$1E ($C403) changes between $40 and $00--bit 7--somewhere in the
>keypress code. I can't find any instruction that does either res
>7,(IY+$1e) or set 7,(IY+$1e). Do bits actually start at 0 when you
>are
yes, bits start at 0.
>I'm trying to figure out where it decides where to jump to when you
>press a
>key like 2nd+mode. Then I could dissassemble the mode code to find
>all the
>IY flags.
this is where it's good to use the emulator to disassemble. you can
trace it a lot easier.
$6aa4 on page $01 is the important bit (for the full-screen menus)
it uses ix like a structure:
ix+$04,$05 = where on screen
ix+$07,$08 = string
ix+$09,$0a = where in memory
ix+$10 = mask
ix+$0f = value
i think all the iy flags on the mode menu have been found, though.
-josh
>
>
>// David Phillips
>// mailto:electrum@tfs.net
>// AIM: electrum32
>
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