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disp4096: keypress cycles through

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This commit is contained in:
Vince Weaver 2018-07-25 14:05:41 -04:00
parent 7c8eefc868
commit ef2b235b36
1 changed files with 22 additions and 10 deletions
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32
fancy_lores/disp4096.s
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@ -43,9 +43,10 @@ WAIT = $FCA8 ;; delay 1/2(26+27A+5A^2) us
;===================
; init screen
start_over:
jsr TEXT
jsr HOME
bit KEYRESET
;===================
; init vars
@ -177,17 +178,21 @@ qloop:
; so we want roughly 22 lines * 4 = 88*65 = 5720 + 4550 = 10270
; - 65 (for the scanline we missed) = 10205 - 12 = 10193
jsr gr_copy_to_current ; 6+ 9292
; 10193 - 9298 = 895
; Fudge factor (unknown) -30 = 865
; GR part
bit LORES ; 4
bit SET_GR ; 4
bit FULLGR ; 4
; Try X=38 Y=52 cycles=10193
; Try X=88 Y=2 cycles=893 R2
ldy #52 ; 2
nop
ldy #2 ; 2
loopA:
ldx #38 ; 2
ldx #88 ; 2
loopB:
dex ; 2
bne loopB ; 2nt/3
@ -245,9 +250,15 @@ page1_loop: ; delay 115+(7 loop)+4 (bit)+4(extra)
;======================================================
; We have 4550 cycles in the vblank, use them wisely
;======================================================
; do_nothing should be 4550+1 -2-9= 4540
; do_nothing should be 4550+1 -2-9 -7= 4533
jsr do_nothing ; 6
lda KEYPRESS ; 4
bpl no_keypress ; 3
jmp start_over
no_keypress:
jmp display_loop ; 3
@ -255,15 +266,16 @@ page1_loop: ; delay 115+(7 loop)+4 (bit)+4(extra)
;=================================
; do nothing
;=================================
; and take 4540-6 = 4534 cycles to do it
; and take 4533-6 = 4527 cycles to do it
do_nothing:
; Try X=29 Y=30 cycles=4531 R3
lda TEMP ; 3
; Try X=4 Y=174 cycles=4525 R2
ldy #30 ; 2
nop ; 2
ldy #174 ; 2
loop1:
ldx #29 ; 2
ldx #4 ; 2
loop2:
dex ; 2
bne loop2 ; 2nt/3