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xmas2019: closer to vapor lock

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This commit is contained in:
Vince Weaver 2019-12-18 22:56:22 -05:00
parent db4e5e58b0
commit cd3e602667
1 changed files with 87 additions and 0 deletions
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xmas_2019/xmas2019.s
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@ -39,8 +39,95 @@ TREESIZE = 12
jsr vapor_lock
; vapor lock returns with us at beginning of hsync in line
; 114 (7410 cycles), so with 5070 lines to go to vblank
; then we want another 4050 cycles to end, so 9120
;=================================
; do nothing
;=================================
; and take 9120 cycles to do it
do_nothing:
; Try X=139 Y=13 cycles=9114R6
nop
nop
nop
ldy #13 ; 2
loop1: ldx #139 ; 2
loop2: dex ; 2
bne loop2 ; 2nt/3
dey ; 2
bne loop1 ; 2nt/3
display_loop:
;==========================
; First 8*4 = 32 lines GR??
; 2080 cycles
bit SET_GR ; 4
bit LORES ; 4
; Try X=1 Y=188 cycles=2069 R3
lda COLOR ; 3
ldy #188 ; 2
bloop1: ldx #1 ; 2
bloop2: dex ; 2
bne bloop2 ; 2nt/3
dey ; 2
bne bloop1 ; 2nt/3
;=====================================
; Next 32*4 = 128 lines HGR2/GR1/HGR2
; 8320 - 8 = 8312
bit SET_GR ; 4
bit LORES ; 4
; Try X=13 Y=117 cycles=8308 R4
nop
nop
ldy #117 ; 2
dloop1: ldx #13 ; 2
dloop2: dex ; 2
bne dloop2 ; 2nt/3
dey ; 2
bne dloop1 ; 2nt/3
;==========================
; Next 8*4 = 32 lines GR ??
; 2080 cycles
bit SET_GR ; 4
bit LORES ; 4
; Try X=1 Y=188 cycles=2069 R3
lda COLOR ; 3
ldy #188 ; 2
cloop1: ldx #1 ; 2
cloop2: dex ; 2
bne cloop2 ; 2nt/3
dey ; 2
bne cloop1 ; 2nt/3
vblank_start:
;==========================================================
;==========================================================
; erase old lines