help with DHR plotting

[Cyrus Roton <croton@ridgecrest.ca.us>]

I need help in debugging a double hi-res plotting routine. The following program steps are used in setting up for DHR plotting:

LDA $C057    ;hires
LDA $C052    ;mixclr
LDA $C050    ;txtclr
LDA $C002    ;mainread
LDA $C004    ;mainwrt
STA $C001     ;store80
STA $C00D     ;0n80col
LDA $C05E     ;an3off

Subsequently, plotting to main or auxmem is selected by 

LDA $C054    or   LDA $C055

The problem is that certain programs (not all of them) which use 80 columns, seem to leave some softswitch or another set to interfere with this plotting. The result is thin vertical bands on the plot. I can load and view DHR properly, I just can't plot p
roperly.

 The only way I have found to eliminate the problem is to shut off and reboot and don't run those other programs prior to DHR plotting. Reset does not help, nor does playing around with the normal 80 col/40 col keyboard commands.

Any advice on this matter will be appreciated.


Cyrus Roton   croton@ridgecrest.ca.us
Ridgecrest Apple User Group