mirror of
https://github.com/g012/l65.git
synced 2024-06-11 10:29:27 +00:00
58 lines
1.1 KiB
Lua
58 lines
1.1 KiB
Lua
dofile "vcs.lua"
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TIM_OVERSCAN = 50 -- TIM64T, 3200 cycles = ~ 42 scanlines
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TIM_VBLANK = 61 -- TIM64T, 3904 cycles = ~ 51 scanlines
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TIM_KERNEL = 17 -- T1024T, 17408 cycles = ~229 scanlines
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location(0xf000, 0xffff)
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section "waitForIntim"
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-- n_{ a=INTIM } ?
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lda(INTIM) -- or a=INTIM
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bne "waitForIntim"
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rts
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section "doOverscan"
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sta{WSYNC} -- WSYNC=a
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lda(2) sta{VBLANK} -- a=2 VBLANK=a
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lda(TIM_OVERSCAN) sta{TIM64T} -- a=TIM_OVERSCAN TIM64T=a
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jsr "waitForIntim"
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section "doVBlank"
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lda(0x0e)
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label ".vsyncLoop"
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sta{WSYNC}
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sta{VSYNC}
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lsr()
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bne ".vsyncLoop"
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lda(2)
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sta{VBLANK}
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lda(TIM_VBLANK)
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sta{TIM64T}
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jsr "waitForIntim"
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section "doKernel"
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lda(TIM_KERNEL)
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sta{T1024T}
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jsr "waitForIntim"
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section "start"
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-- clear zeropage
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cld()
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ldx(0)
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txa()
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label ".clearLoop"
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dex()
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tsx()
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pha()
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bne ".clearLoop"
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-- main
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label "mainLoop"
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jsr "doOverscan"
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jsr "doVBlank"
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jsr "doKernel"
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jmp "mainLoop"
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section{ name="vectors", org=0xfffc }
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word{ "start", "start" }
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