Radio Shack TRS-80 Model II Reference Manual page 212

- Model II TRSDOS
Transparent~ode
The transparent mode overrides all data translation. All data bytes go directly to the
printer. There is no examination of content. The line and character counts are not
updated.
Normally,
TRSDOS
"intercepts" certain control characters and interprets them.
This allows
TRSDOS
to provide printer-related features which may not be available
from the printer.
For example, tabs
(X"09')
are intercepted so that
TRSDOS
can send the appropriate
number of spaces to provide the tab function. Form feeds
(X"OC
or
X"OB')
are
intercepted so that
TRSDOS
may advance the paper to the top of the next form.
Code translation may be overridden individually by special settings of the printer
initialization values. See
SVC
PRINIT
for details.
Dummy Output
~ode
The dummy mode "throws away" all printer output and returns with a' 'good" (Z
flag set) return code. During dummy mode operation, the line count and character
count remain unchanged.
Auto Line Feed
Normally, the
TRSDOS
printer driver does not print line feeds after carriage returns.
This is because most Radio Shack printers do an automatic line-feed after every
carriage return.
If your printer does not perform automatic line-feeds after carriage returns, you
may enable the
TRSDOS
auto line-feed function.
While the function is enabled, a line-feed will be output after each carriage return.
This is true in all modes including the transparent mode.
Note: In the auto line-feed mode, you may send a carriage return with no linefeed
by outputting the code
X"8D'.
If the printer is capable of overprinting, this latter
code will return the carriage without advancing the paper.
Precedence of Options
The following table shows which options have priority over others. Options are
listed in order of descending priority.
Spool Capture-Mode (See
SPOOL
command)
Dummy Mode
Auto Line-Feed after Carriage Return
Transparent Mode
Normal Mode
248