Radio Shack TRS-80 Model II Reference Manual page 257

Technical Information
To do this, take the number of program bytes and increment by two. Note that
values greater than
255
"wraparound" to
0, I,
and
2.
Here is a table:
Number of bytes after
the address
(program data only)
1
2
3
253
254
255
256
Use this value for
the length byte itself
3
4
5
255
o
I
2
3. The load address tells
TRSDOS
where the data in this block will be loaded into
RAM.
Bytes will be loaded serially starting at the load address. The load address
must allow the entire block of program data to load in the" User" area of
RAM
(see" Memory Requirements of
TRSDOS").
Comment Blocks
Comment blocks consist of the following:
Byte #
1
2
3-end
Notes:
Contents
Block Identifier ( =
5)
Length - number of bytes in the comment
Comment
1. For comments, the block identifier always equals binary
"5".
2. The length byte gives the number of bytes in the comment, i.e., the number of
bytes after the length byte itself. This sum ranges from
0
to
255:
Length Byte
o
1
2
255
Length of Comment
o
1
2
255
293