Re: Lo-res/Double lo-res (was: Wacky Game idea)

[rubywand@aol.com (RUBYWAND)]

In article <615340966wnr@klatch.demon.co.uk>, John Le Febvre
<john@klatch.demon.co.uk> writes:

>...
>          LDA COLOR  [NXTCOL]
>          CLC
>          ADC #$03    ....
>          AND #$0F     [SETCOL]
>          ...
>
>From what I can tell, the LDA COLOR bit is never executed.  I know it's
>only 5 bytes, but does anyone know if it exists in later ROMs? ....

    This code goes back to at least 1977. Yet, a scan of our II+ ROMs
shows no JSR or JMP or branch to NXTCOL ($F85F). Nor do $5F F8 or $5E F8
appear in any table. Maybe NXTCOL is used by integer BASIC. It could be
useful in a Lo-res cursor routine or as some kind of multi-color activity
indicator during casette tape I/O.

    SETCOL ($F864) is accessed once, at $F253 (4C 64 F8). Possibly, it is
used by the Lo-res VLIN command. 

    




Rubywand