SD_SCROL/IOW_SCRA etc

These traps scroll all or part of a window.

Trap	Value in D0.B	Action
SD_SCROL/IOW_SCRA	$18	Scroll all of window
SD_SCRTP/IOW_SCRT	$19	Scroll top of window
SD_SCRBT/IOW_SCRB	$1A	Scroll bottom of window

Call Parameters		Return Parameters
D0.B	See above	D0.L	Error return.
D1.W	Distance to scroll	D1.L	Corrupted.
D3.W	Timeout	D3.L	Preserved.
A0.L	Channel ID	A0.L	Preserved.

ERR_NC	Not complete.
ERR_NO	Channel not open.

All registers not shown above are not used on entry and are preserved on exit.
Scrolling means that the area selected will be moved up or down by an integral number of pixels. A positive number in D1.W will cause a downward movement. The vacated rows of pixels will be filled with paper colour.
The top of a window is defined as all the rows above the line on which the cursor lies (the cursor line).
The bottom of the window is defined as all the rows below the cursor line.

The example below shows the use of this trap call to scroll text up by one line. It is assumed that A0 contains the correct channel ID.

scroll  moveq   #sd_scrol,d0    ; $18
        moveq   #-10,d1         ; Up one line
        moveq   #-1,d3          ; Timeout
        trap    #3              ; Scroll up a line
        tst.l   d0              ; OK? . .
        bne     error           ; . . no!

SD_SCROL/IOW_SCRA etc

Errors

Notes

Example

QDOS Internals