ID:SP Serial Port Printing in DESQview
Quarterdeck Technical Note #107
by Stan Young
Q: How can I initialize my serial printer with DESQview?
A: If you are going to initialize a serial port in a DESQview
window, you have set up the program information file for that
window so that the option "Uses serial ports" is either "Y" or
the specific port being used. Otherwise the COM port cannot be
accessed due to the port protection mechanism of DESQview.
Trying to use the DOS MODE command to initialize a COM port from
a window which has "Uses serial ports" set to "N" will result in
a DOS message: "Invalid parameter 'COM?' since DOS will not see
the port as available.
Q: Is there a "best way" to set up for serial printing in
A: Set up as shown above, a program running in DESQview can
directly access a serial port for printing. However, a better
solution is to initialize the port with MODE and redirect an LPT
port to the serial port BEFORE running DESQview. If you have
redirected an LPT port to the serial port before running
DESQview, you can simply print to the port without regard to how
the "Uses serial ports" parameter is set, since the actual
redirection of print is handled outside of DESQview.
Q: But I also have a parallel printer. How can I redirect my
serial port to LPT1?
A: Don't select an LPT port which is already in use. If you
already have a real parallel printer, simply select the next
logical LPT port to redirect. Remember that a printer port can
be addressed as a logical device by DOS --that is, you do not
have to actually have a port set up as LPT2 in order to direct
COM1 to it. The logical parallel printer ports supported by DOS
are LPT1, LPT2 and LPT3.
Copyright (C) 1991 by Quarterdeck Office Systems
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