SAGA_VIDEO_VSSTRT Register

Change the current SAGA Video ModeLine VSSTRT attribute.


  • SAGA_VIDEO_VSSTRT
  • 0xDFF30A
  • Write-Only
  • 16-bits

See ModeLine for more information.

Property Short Description
VPIXEL Height Number of vertical pixels drawn to the visible part of the screen.
VSSTRT-VPIXEL Front Porch Amount of black pixels drawn on the bottom of the screen.
VSSTOP-VSSTRT Vertical Sync Amount of time it takes to move back up to the first line of the screen
VTOTAL-VSSTOP Back Porch Amount of black pixels drawn to the top of the screen.

The following ASM snippet shows how to fully set a valid ModeLine.

MAIN:
  lea    MyModeLine,a0   ; Load MyModeLine in A0
  move.w (a0)+,$dff300   ; SAGA_VIDEO_HPIXEL
  move.w (a0)+,$dff302   ; SAGA_VIDEO_HSSTRT
  move.w (a0)+,$dff304   ; SAGA_VIDEO_HSSTOP
  move.w (a0)+,$dff306   ; SAGA_VIDEO_HTOTAL
  move.w (a0)+,$dff308   ; SAGA_VIDEO_VPIXEL
  move.w (a0)+,$dff30A   ; SAGA_VIDEO_VSSTRT
  move.w (a0)+,$dff30C   ; SAGA_VIDEO_VSSTOP
  move.w (a0)+,$dff30E   ; SAGA_VIDEO_VTOTAL
  move.w (a0)+,$dff310   ; SAGA_VIDEO_HVSYNC
  rts

MyModeLine:
  dc.w 800,832,912,1024,600,604,608,625,1 ; "800x600@60" 38.400000

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  • saga_video_vsstrt.txt
  • Last modified: 2016/05/23 21:34
  • by flype