b964f1fa7b
There is now a small header for the MSU video files: uint16_t framecount; uint8_t std_frameduration; uint8_t alt_frameduration; uint8_t alt_durfreq; framecount is the number of frames in the video. std_frameduration is the usual duration of a video frame in SNES video frames. alt_frameduration is an alternate duration alt_durfreq specifies after how many frames the alternate duration should be used for a single video frame. The frame counter is reset afterwards. This allows to use simple pulldown patterns. e.g. for a 29.97fps video you need 2:2 pulldown (display every video frame for two SNES video frames). In this case, std_frameduration, alt_frameduration, alt_durfreq are: 2, 2, x (any number is good for the freq in this case) For 23.976fps video one would do 3:2 pulldown (displaying every other video frame for three SNES video frames). The format would be: 2, 3, 1 Frame size is always 224x144, 32512 bytes (4 tiles wasted to save tilemap memory), followed by 512 bytes of palette.
57 lines
1002 B
Plaintext
57 lines
1002 B
Plaintext
spc_upload:
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rep #$20 : .al
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sep #$10 : .xs
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lda #$bbaa ; wait for IPL bootup
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- cmp $2140
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bne -
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; IPL portmap outside transfer state:
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; $2141 = command (transfer / run)
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; $2142-3 = target address
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; $2140 = trigger
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lda @spcaddr
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sta $2142
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ldx #$01 ; transfer
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stx $2141
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ldx #$cc
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stx $2140
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; wait for echo
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- cpx $2140
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bne -
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; IPL portmap inside transfer state:
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; $2140 = sequence number
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; $2141 = payload
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; init counters
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sep #$20 : .as
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ldx #$00 ; sequence counter
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lda @spclen
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tay ; countdown
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spc_loop
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lda @spccode, x ; fill data byte
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sta $2141 ; write data...
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stx $2140 ; ...and write sequence counter
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- cpx $2140 ; wait for echo from IPL
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bne -
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inx ; increment sequence counter...
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dey
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bne spc_loop ; if not, do it again
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spc_end
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rep #$20 : .al
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lda @spcexec
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sta $2142 ; set exec address
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stz $2141 ; command: run
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ldx $2140
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inx
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inx
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stx $2140 ; send sequence end / execute
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- cpx $2140 ; wait for last echo
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bne -
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sep #$20 : .as
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rep #$10 : .xl
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rts ; and done!
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