Microcom 470 - Manual (Page 89)

Chapter 9 Soft Fonts
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470 Operators Manual 81
Default Char - byte Default character to be imaged if character code is less
than first character or larger than last character
Filler - byte Always 0
LLC - word Offset to the first character tier, from the start of the first
character in words. This is the lower left hand corner of
the first character. This pier is the ((cell height-1) * pier
size)
NonPropOff - word Offset, in words, to the non-proportional character pointer
table. If there is no non-proportional pointer table, then
point to the proportional pointer table, (which is always 0
offset from this point in the structure)
Character Pointer Table:
For each character from First Character to Last Character there is a pointer entry. If that
character image does not exist, use the same values in the table as the default characters
pointer entry. Likewise, if no lower case characters exist, you can substitute in the upper case
character pointer array values.
Character Pointer Table:
PARAMETER SIZE DESCRIPTION
Pier Offset - word Offset, in bits, from the start of a pier to the character data
Kerning - byte Offset, in dots, from the left edge of the cell to the left
edge of the character image
Descent - byte Offset, in dots, from the bottom of the character cell in the
font to the baseline of the destination character cell
Image Width - byte Width of the character image
Cell Width - byte Cell width of the character
If the font has a non-proportional character table, it would follow the proportional character
table.
Character Pixel Array:
The character pixel array is a system of tiers of character image widths with no white space
between them. If, for example, the character height is 20 dots, there would be 20 tiers.
Therefore, each tier represents a scanline of the characters.
The lower left hand corner of the character data is the last encoded pier. The data in a byte of
the pixel array may contain the image data of more than one character.
The size of a tier should always be an integral of 32, even if filler must be added to the data.