Asynchronous Terminals and Printer Processes Programming Manual

PRINTER PROGRAMMING CONSIDERATIONS
Initializing the DAVFU
immediately after a call to SETMODE 28 (reset to configured
values). This procedure ensures that the printer is at top of
form before loading the default DAVFU. Loading the DAVFU causes
the top of form to be reset to the current line.
If the previous form length is different from the default, the
approach just described is not effective since the requested
top of form will advance the paper the wrong number of lines.
For this reason, when loading the printer with standard 66-line
(11-inch) paper after nonstandard-size paper has been used, turn
the printer off and then back on to force the form length to the
default setting.
When using nonstandard-size paper, your program should display a
message asking the operator to align the paper after the DAVFU is
loaded.
Loading the DAVFU
You can override the default DAVFU settings by calling CONTROLBUF
1. Any previous lines of text will be printed before the DAVFU
is loaded. Loading the DAVFU causes the top of form to be reset
to the current line.
The buffer passed to CONTROLBUF should contain one word for each
line on the page. Bits 0 through 11 of each word represent
channels 0 through 11, respectively, for that line. A 1 in
any of these bits indicates a stop in the corresponding channel.
Bits 12 through 15 are unused and must be zeros.
The format of each word in the DAVFU buffer is shown in
Figure 7-1.
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