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Re: DGR...

> Do they?  Do you have to flip 80STORE for odd/even columns?  I remember using ampersand routines for double-lores graphics in the 90's.  I might still have them somewhere.
> 
> I can help with the asm if you can send me specs (though don't expect a fast turnaround -- I have a lot of fires going).


Yes.  But the math still had to be done before jumping to the plot routine. Something as simple as this was done.

PLOT EQU $F800

 LDA #LORES COLOR*17
 STA $30

 LDX #VERTICAL LINE (0-47)
 LDA #(PIXEL 1-79)
 LSR
 PHA
 LSR
 PLA
 TAY
 TXA
 BCS PLOT
 STA $C055
PLOT EQU *
 JSR PLOT
 STA $C054
 ...