The 80 Column: PrData Text Translation Files
by Alan Wrigley

Each of the files inside the directory !PrData.Files is a text file containing the necessary data required by the RISC OS release 2 printer drivers to enable them to print international characters when printing in text mode. The file entitled FX80 is for Epson-compatible printers which use the code sequence ESC "R" to access international character sets. The file entitled Page437 is for the Star LC range, and any other printers which support the IBM character set (Code Page 437) and which is accessed by the code sequence ESC "6". The file entitled Page850 is for Canon BubbleJet printers and any others which support Code Page 850 and also use the code sequence ESC "6". Note that in some cases you may have to have a DIP switch in your printer set to IBM mode.

To use these files, you must first open the printer driver's application directory, for example !PrinterDM. Inside you will find a text file called PrDataSrc. Load this into a text editor, and find the printer definition for the required printer. Now insert the text from the FX80, Page437 or Page850 file (as appropriate) at the end of the printer definition. Now look at the start of the definition for a line beginning "text_alias" or "nlq_mode". If the latter is present you can ignore the rest of this paragraph. If the "text_alias" line is present, you must replace this completely with a line which reads as follows: "nlq_mode:      1". Now go to the start of the PrDataSrc file and find the two lines "total_draft_printers" and "total_nlq_printers". These will both be followed by a number, and you must increase this number by one.

Finally, save the modified PrDataSrc file, and then run the PrSquasher program to compile the PrData file from the source file which you have just modified. Further details on how to do this are given in the help file which accompanies the printer driver.

The files supplied here allow all the characters from the Latin1 set which are available from the printer to be printed. In the case of FX80 and Page437, this will not be the complete Archimedes character set since not all characters are available from these printers. Page850 should, however, allow you to print all the characters which you can enter from the Archimedes keyboard, either from the keys themselves, by using Alt in combination with the ASCII code, or by using an application such as our own PolyGlot which enables you to enter the characters from a window using the mouse.
