QDOS Internals

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.

====== UT_MTEXT/UT_WTEXT - Vector $D0 ======

This vector sends text to a channel.

^Call Parameters^^Return Parameters^^
|D0.L|Unused |D0.L|Error code.|
|D1.L|Unused |D1.L|Corrupted.|
|D2.L|Unused |D2.L|Corrupted.|
|D3.L|Unused |D3.L|0 or -1|
|A0.L|Channel ID |A0.L|Preserved.|
|A1.L|Pointer to text |A1.L|Corrupted.|
|A2.L|Unused |A2.L|Corrupted.|
|A3.L|Unused |A3.L|Corrupted.|


===== Errors =====
|ERR_NC|Not complete (only for A0=0)|
|ERR_NO|Channel not open|
|ERR_DF|Drive full|
===== Notes =====
  * All registers not shown above are not used on entry and are preserved on exit.
  * If A0 = 0, the channel is #0. If this channel is in use #1 is tried. Although not recommended by Sinclair it seems to work.
  * If A0 = 0, D3 is set to 0 on exit, otherwise D3 is -1.
  * As is usual D0 is tested before exit except for QDOS versions 1.03 and earlier.
  * The text to which A1 points is in the usual form, a word containing the length followed by that number of characters.
  * A programmer who wants LF at the end of the string must include it.


===== Example =====
The example below shows the use of this vector to print a message.

<code>
Prt     movea.w UT_MTEXT,a2     ; UT_MTEXT vector address.
        lea     mess,a1         ; Address of message.
	jsr	(a2)		; Print the message
	bne.s	Error_handler	; Oops! (QDOS versions later than 1.03)
        rts

mess    dc.w    6
        dc.b    'Hello',10
</code>

QDOS Internals

User Tools

Site Tools

Page Tools