SD_SETMD/IOW_SOVA
This trap sets the character writing or plotting mode.
Call Parameters | Return Parameters | ||
---|---|---|---|
D0.B | $2C | D0.L | Error code. |
D1.W | Mode | D1.L | Corrupted. |
D3.W | Timeout. | D3.L | Preserved. |
A0.L | Channel ID. | A0.L | Preserved. |
A1.L | A1.L | Corrupted. |
Errors
ERR_NC | Not complete. |
ERR_NO | Channel not open. |
Notes
- All registers not shown above are not used on entry and are preserved on exit.
- The mode given in D1 is:
- -1 ink XORed into the background.
- 0 character background is strip colour; plotting is in ink colour.
- 1 character background is transparent so it is not overwritten; plotting is in ink colour.
Example
The example below shows how to use this trap call to make printing appear and then disappear. The mode is set to -1 then printing can be done. After a wait the printing is again done and it now disappears. It is assumed that A0 contains the channel ID.
Setmd moveq #-1,d1 ; Set XOR mode. moveq #-1,d3 ; Timeout. moveq #SD_SETMD,d0 ; $2C trap #3 ; Set the mode tst.l d0 ; OK? . . bne error ----> ; . . no! bsr print ; Print something at 0,0 bsr wait ; Wait for a bit. bsr print ; The printing disappears.