This Chapter provides the bridge between the Amiga's Parallel Port and AMOS Professional. One parallel channel may be opened at a time, so if a printer is already attached to the Parallel Port, the Parallel device may not be opened at the same time as the Printer device.
In fact, accessing the Parallel device has three main advantages over the Printer device:
There are few disadvantages, although control over sequence conversion is not possible, and screen dumps cannot be made via the Parallel Port.
instruction: open the Parallel Port for reading or writing
This instruction initialises the Parallel Port for use by an AMOS Professional program. The first time that this command is used in any programming session, the "Parallel.device" driver will be loaded into memory. If it is not available, you will be prompted to insert the relevant disc automatically.
instruction: close the parallel port
This command simply closes the Parallel port.
instruction: send a string of characters to the Parallel Port
Parallel Send text$
This is very similar to the PRINTER SEND command, which is explained in Chapter 10.3, except that text data is transmitted exactly as it appears in the original source string. There is no translation of code, so that any Escape codes will be interpreted directly by a printer. Please check your printer documentation for details of allowable control codes.
If data is output to a printer via the Parallel Port, each line should be terminated by a single line- feed, which is Chr$(10). This tells the printer to print a new line onto paper, starting at the current position. If the line-feed is omitted, nothing will appear to happen! Characters are transmitted using multi-tasking, so your main program will not wait for printing to be completed, but will continue immediately from the next instruction.