xmas2018: hgr scroll: preserve colors (mostly)

This commit is contained in:
Vince Weaver 2018-12-20 10:53:22 -05:00
parent a92ec7869c
commit 5d4005567f

View File

@ -276,15 +276,23 @@ hgr_scroll_line_loop:
sta NEXT ; 3
dey ; restore Y ; 2
; if ((count mod 7==2) || (count mod 7==6)) {
; ram[HIGH]=ram[NEXT]&0x80;
;}
; else {
lda COUNTL
cmp #2
beq move_high_bit
cmp #6
beq move_high_bit
bne keep_high_bit
move_high_bit:
lda NEXT
jmp done_high_bit
keep_high_bit:
lda CURRENT ; 3
done_high_bit:
and #$80 ; 2
sta HIGH ; 3
; }
cpy #39
bne not_thirtynine
@ -293,7 +301,6 @@ hgr_scroll_line_loop:
lda (INL),Y
sta NEXT
ldy TEMPY
; if (y==39) ram[NEXT]=ram[y_indirect(INL,0)];
not_thirtynine:
lda NEXT ; 3