Mapping Host Font Resources to Printer Resident Resources

Fonts

Host font resources are used to establish a connection between a character set, which defines what the printed characters look like, and a code page, which defines which character corresponds to each input character value.

The host software includes tables that map characters sets and code pages to printer resident resources. If a print job makes use of a font which refers to a resource that does not appear in these tables, the print job is marked as unprintable and held.

An error condition would also be generated if the resource was not supported by the target printer.

Character Sets

Host character sets have an 8 character name of the form C0yyyyyy where yyyyyy is unique for each combination of typeface, size and attributes. For example, C0D0GT18 could be a Gothic Text style font 18 characters per inch in a medium weight. An italic or bold version of the same character set would have a different name.

The mapping table would map this 8 character name to a 2 byte "resident font global id" and 2 bytes of font attributes (for example, bold or italic).

Code Pages

Host code pages have an 8 character name of the form T1yyyyyy where yyyyyy is the code page name. For example, T1D0BASE might include upper and lower case alphabetics, numerics, symbols and line-drawing characters Some code points could be invalid which results in an I/O error message if a page containing such a character value is printed.

The mapping table maps the 8 character name to a 2 byte "resident code page global id".

Both the "resident font global id" and "resident code page global id" are defined by the printer hardware.

PSF module APSRFTBL defines the table mappings. There is some discussion of this subject in the Flash "The 6400 Printer and PSF for OS/390"
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