[Coco] OS-9 Font file format

[L. Curtis Boyle]

The main OS-9 Level 2 manual does list this; it's under the GPLoad command in the Windows section. 1B 2B is the GPLoad command escape sequence.

L. Curtis Boyle
curtisboyle at sasktel.net



On Sep 19, 2011, at 4:03 PM, Mike Rowen wrote:


> 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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