Peripheral Device File Names

For BBj-specific information, see Miscellaneous Language Changes for BBj.

While operating systems allow you to name your own disk files, rarely do they allow you to name your own devices such as terminals and printers. Special names for standard devices called aliases cause devices to be recognized. An alias may be up to 6 characters long and are associated to real system devices in the configuration file.

Although PRO/5 may support many different devices depending upon the host system, PRO/5 will always recognize the following four devices:




Display terminal

Display terminal, such as a computer monitor.

Tnwherenis a terminal number or name.

T0- First terminal on a system (and the only terminal on a single user system).

T1, T2, etc. – Additional terminals.

device alias beginning withTis considered to be a terminal device.


Printer. PRO/5 keeps a line buffer internally for each printer. This allows forward and backward movement on a print line even though some printers cannot do this. The internal buffer may be bypassed through mnemonic control

LP – Main system printer.

P1, P2, etc. – Additional printers.

Any device alias beginning with L or P is considered to be a printer. device.


A graphics device may be a raster display, printer, or pen plotter. Graphics devices come with their own set of mnemonics controlling the graphics output. Any device starting with a "D" will be considered a graphics device by PRO/5.

Dn, wherenis a number.

device alias beginning withDis considered to be a graphics. device.

Standard I/O

Terminal and keyboard for input and output. Channel 0 is always opened to the standard input and output files for that program.

Normally, the file name associated with channel 0 is the terminal alias (T0, T1, etc.). However, if PRO/5 is running in background or with redirected standard I/O, the file name associated with channel 0 will be IO, which has no special capabilities other than to read and write data.

Control of these devices is done through the use of mnemonics. For example:


The 'CS' in the example means "clear screen." PRO/5 will figure out how to perform the operation.