.Dd September 2017
.Dt klg2 1
.Os klg2 program
.Sh NAME
.Nm klg2
.Nd Print a PBM file on a Casio KL-G2 label printer
.Sh SYNOPSIS
.Nm klg2
.Op Fl FCHvh
.Op Fl m Ar margin
.Op Fl t Ar tapesize
.Op Fl c Ar cutmode
.Op Fl d Ar density
.Sh DESCRIPTION
The
.Nm
program reads a PBM file on the standard input and prints it on a Casio
KL-G2 label printer connected to the USB port. Options are provided for
manually feeding or cutting the tape (no image is read in that case).
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl F
Feed the tape and exits. Equivalent to the manual feed from keyboard.
.It Fl C
Cut the tape and exits. Tape is fed a little due to how the mechanism
works. Equivalent to the manual cut from keyboard.
.It Fl H
Do an half-cut and exits. There is no equivalent from the keyboard, and,
in fact, the operation itself is of dubious utility.
.It Fl v
Enables verbose logging on standard error of the communication with the
printer. Only for debugging and troubleshooting.
.It Fl m Ar margin
Select the pre- and post- printing tape feed. Values from 1 to 3 are
equivalent to the small, medium, large margin options in the printer
FORM menu. Setting margin to 0 put the printer in no-feed mode and
inhibits the cutter. The default is 1 (small margin).
.It Fl t Ar tapesize
Select the tape width in millimeters; accepted values are 6, 9, 12, 18
and 24. This is only used for verifying the installed cartridge (the
printer detects keying holes in the cartridge's body) and doesn't affect
the actual print area (all the 128 printhead elements are available).
The default is 12 millimeters.
.It Fl c Ar cutmode
Select the cutter operation mode. 0 disables the cutter. 1 operates an
half cut at the beginning of the label and a full cut at the end. 2 does
a full cut both at the beginning and at the end of the printed label.
The default is half-cut mode.
.It Fl d Ar density
Sets the print density. 1 is lighter and 5 is darker. Default is 3.
.El
.Pp
The image to be printed is read from the standard input and must be in
raw PBM format. The maximum height is 128 pixels (the printhead size)
while the length is substantially limited by the available tape and
memory (the printer can spool in pages so printer memory is not an
issue).
.Pp
Images shorter than 128 pixel are centered on the print area but the
printhead is driven on the whole width independently on the tape width
selected.
.Pp
The printer has a thermal 200dpi printhead (8 points per millimeter),
with an active area of 16mm. The full resolution is only available with
18mm and 24mm tapes. The nominal print area for 12mm tape is 80 points,
but about 88 are usually accessible on the tape. For smaller tapes the
active area is in proportion.
.Pp
It is not recommended to try printing outside the tape since the
printhead could be damaged.
.Sh EXIT STATUS
.Ex -std
.Sh HISTORY
.Nm
was developed by reverse engineering the USB protocol used by the
proprietary Casio FA-3000 Label Printing Software. Some information were
also obtained by cross-referencing the protocol with the Pegg EL
software written by Daniel Amkreutz and Alex Perry for the EL label
printers.
.Pp
Unfortunately the Casio documentation doesn't seem to be still available
and many commands have no known meaning.
.Sh BUGS
.Nm
was tested only on one printer and only with 12mm tape. Since at the
time of writing the KL-G2 is the only USB connected label printer
actively sold by Casio there shouldn't be compatibility issues.
.Pp
Anyway the protocol remained mostly the same from the EL series so it
should be relatively easy to adapt the
.Nm
program for older or newer printers.