With the introduction of the HP LaserJet IID printer, Hewlett-Packard expanded the typeface value field (in the font header) from a one-byte to a two-byte value field, thus expanding the typeface range from 0-255 to 0-32767. This expansion allows for additional typefaces.
Prior to the HP LaserJet IID printer, typeface values used a single byte (8-bits for a range of 0-255) for font selection. This value, referred to as the typeface base value, was used to identify fonts for selection. With the addition of the second byte in the typeface value field, one bit was added to the typeface base value range, increasing it from 8 bits to
9 bits (for a range of 0-511). This allows a greater range for typeface base value selection.
In addition to expanding the typeface base value, two other values were included in the two-byte typeface value: vendor number and vendor version. The vendor number identifies the font vendor and the vendor version identifies the version of the font. These two values are for a vendor to create an updated version of the typeface. The three values together represent the typeface family value. Refer to the PCL 5 Printer Language Technical Reference Manual Chapter 11,“Font Creation - Typeface Family,” for a more complete description of this two-byte typeface family value.
With the introduction of the HP LaserJet 4 printer, HP redefined the typeface field again, this time eliminating the vendor version identifier and expanding the typeface family to encompass the 12 least significant bits (bits 11-0) of this 16-bit field (see the field description for “Typeface” in Chapter 11).
