Specifications

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Now you can print to the serial printer as though it is connected to the system's parallel printer
port.
You can return the printer device to the Parallel Printer port with the following command:
A>MODE LPT1<Enter>
If desired, MODE commands can be included in your system's AUTOEXEC.BAT startup file to
assign the printer function to a serial port. Also, additional MODE commands can be used in
other batch files to dynamically reassign the DOS printer device function as often as required
during system operation.
Printer Cabling and Setup
The printer must be set for a suitable baud rate, and appropriate data and handshake signals must
be connected between the computer's and the Printer's serial connectors. In particular, be sure to
connect the serial port's "Ready to Receive Data" handshake output signal to the serial port's Clear
to Send (CTS) input handshake input signal. In addition, the board's Data Set Ready (DSR) input
handshake signal must be true, for the ROM-BIOS to send output data, so connect that signal to
an appropriate handshake output signal from the printer, or loop it to the board's DTR output
signal. Chapter 2 describes the jumper options available for configuring the serial port.
3.5.4 Using a Serial Modem
In addition to their use as console or serial printer ports, either of the board's two RS232C serial
ports can be used as a modem interface. Most PC communications programs control the serial
port hardware directly, rather than using DOS or ROM-BIOS functions. When configured as
described in Chapter 2, the board's serial ports are fully compatible with those of standard AT's
and PC's, so all such software should work properly.
When connecting a serial modem, be sure to connect appropriate input and output handshake
signals, depending on what is required by the communications software you use. Most
communications programs take care of initializing the serial port baud rate and data
characteristics; if not, be sure to use the DOS MODE command to initialize the port.
A number of powerful communications programs are available which can be used to control
communications applications via a modem. Several of these programs offer powerful "script"
languages, which allow you to generate complex automatically functioning applications with very
little programming effort. Examples are: PCTALK, PROCOMM, XTALK, and MIRROR.