[Coco] OS-9 Font file format

Mike Rowen mike at bcmr3.net
Mon Sep 19 18:03:44 EDT 2011


Can anyone point me to detailed information on OS-9 Font files? I have
conjectured most of it, but wondering if there is any genuine spec for
these?
I can find no references to the first, second, and fifth bytes that begin a
font entry. I found no detailed info in the OS-9 manuals, Multi-Vue, or
Inside OS-9 LII books. I have not
encountered any different values for these bytes, so in the end, its not a
show stopper. However, I like to understand how things work. :) Any
details on font files is appreciated. Also, my conjecture about the 6th -
11th bytes may be incorrect. Perhaps the answer lies in NitrOS9 source code?

For example, the first 11 bytes of the OS-9 stdfonts is:

1b 2b c8 01 05 00 08 00 08 04 00

Byte 1 ???
Byte 2 ???
Byte 3 is the group (c8= group 200)
Byte 4 is the buffer number (01)
Byte 5 ???

The rest of this is conjecture based on looking at the different fonts:

Byte 6 & 7 is the font width in pixels (00 08 = 8 pixels wide)
Byte 8 & 9 is the font height in pixels (00 08 = 8 pixels wide)
Byte 10 & 11 is the number of bytes in the font (04 00 = 1k or 1024 bytes)

I also see that after the 3rd font in the stdfonts file (pulled from
NitrOS9), there are references to group 206 (ce) and its not clear what all
the info after the font 3 bytes is about, though I have not spent any time
yet attempting to reverse engineer the end bits of the font file. Thanks.

Regards,
-Mike Rowen



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