These traps clear the whole of a window or parts of it.
Name | Value of D0.B | Action |
SD_CLEAR/IOW_CLRA | $20 | Clear all window |
SD_CLRTP/IOW_CLRT | $21 | Clear top of window |
SD_CLRBT/IOW_CLRB | $22 | Clear bottom of window |
SD_CLRLN/IOW_CLRL | $23 | Clear all line |
SD_CLRTT/IOW_CLRR | $24 | Clear to line end |
Call Parameters | Return Parameters |
D0.B | See above | D0.L | Corrupted? |
D1.L | | D1.L | Corrupted. |
D2.L | | D2.L | Preserved. |
D3.W | Timeout | D3.L | Preserved. |
A0.L | Channel ID | A0.L | Preserved. |
A1.L | | A1.L | Corrupted. |
ERR_NC | Not complete. |
ERR_NO | Channel not open. |
The example below shows the use of this trap call to clear a window. It is assumed that the channel ID is in A0.L.
clear moveq #SD_CLEAR,d0 ; $20
moveq #-1,d3 ; Timeout
trap #3 ; Clear window
tst.l d0 ; OK? . .
bne error ; . . no!