Difference between revisions of "VDU 1"
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Latest revision as of 19:13, 8 March 2015
Sends the next character to the printer only.
| Syntax | VDU 1,<numeric>
|
| Character stream (hex) | 01 <character>
|
| Description | Sends the <character> to the printer only, even if it is the printer ignore character. |
Description
VDU 1,n sends ASCII value n to the printer
stream. A print job must first have been started with
VDU 2. The screen is not affected. Whether or not
n matches the printer ignore character, it reaches the
printer.
This code is useful for sending escape sequences or graphics to the printer as they are not corrupted by ignore character filtering. On the Master this filtering can be turned off and the printer programmed directly, meaning OSWRCH calls are cut in half.
If the screen has been disabled with OSBYTE &03 then this command is never received by the VDU driver and has no effect.
If the independant printer driver has been turned on with OSBYTE &03 and
the VDU driver has not been turned off, then the printer driver will
receive characters 1,n,n. See the diagram under OSWRCH.
Under MOS 1.20 if the display has been disabled with VDU 21,
the printer will receive two copies of n. See VDUCHR.
-- beardo 21:07, 14 September 2007 (BST)
