SET
Sets a driver or filter program
to
a device. This command is for
advanced programming applications.
You can use SET
to
tell TRSDOS the name of a filter or driver
program that you are going to use.
A driver program channels data to or from a device.
If
it is outputting
to a device, it converts data
to
the device's format. If it is inputting
from a device, it converts the data to the computer's format.
A filter program filters data before it
is
sent out or after it
is
received.
Once the device
is
SET, it remains SET until it
is
RESET. You cannot
SET
an
active device.
Setting
a
Driver
Program
Advanced Programmer's Command
SET
devspec [TO] driver filespec [parameters]
Loads driver filespec into memory and sets it
to
devspec. The driver
filespec can
be
one of your own driver programs.
Once you set a system device to a driver, the device
is
controlled by
your own driver program, rather than the TRSDOS driver program.
The parameters are values sent to the driver filespec. These
parameters are totally independent of the SET command. They are
determined only by the needs of your driver program.
Example
Within TRSDOS is a driver program that sends printer output to the
parallel port. Suppose
you
write a driver program named
SERIALlDVR that sends printer output to the serial port.
SET
*S
P
TO
SERI
ALI
Dl.JR
(ENTER)
loads SERIALlDVR into memory and sets it to the device *SP.
ROUTE
*PR
TO
*SP
(ENTER)
routes data going to the printer to the device *SP. Now any input to
the printer goes to the SERIALlDVR program. The SERIALlDVR
program,
in
turn, sends the output to the serial port.
By using a LINK command instead of the ROUTE command, data
sent
to
*PR
is
sent
to
the TRSDOS parallel printer driver.
It
is also
sent (via the LINK) to the serial driver and then to the serial printer.
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