Radio Shack TRS-80 Model II Reference Manual page 94

Model II TRSDOS
RECORD FORMAT
Records must be sent as follows:
CHARACTER
NUMBER
CONTENTS COMMENTS
1 "-"
Sync-character to indicate beginning of
I··
record.
2
High nibble of
record length (N)
This 2-byte sequence gives the number of
byte
PAIRS
in this record. Zero means 256
3
Low nibble of
byte pairs follow.
record length (N)
4
High nibble of msb
of loadaddr.
5
Low nibble of msb
This 4-byte sequence gives address
of load addr.
where the data is to start loading. Address
6 High nibble of Isb
specified must be in the user area
[X'2800',
TOPj.
of load addr.
Low nibble of Isb
....
of load addr.
8 High nibble of Isb
of
EOF
(end of file) This byte-pair gives the
EOF
code. Any
code
non-zero value means end of file (no more
records follow). A value of zero means
9 Low nibble of
EOF
more records follow.
code
to
First byte of first
data. pair
First byte is
ASCII
code for first
hex
digit;
second byte is
ASCII
code for second hex
Second byte of first
digit.
data pair
8
+
(N*2) Fi rst byte of last
data pair
Last pair of data characters
9
+
(N*2)
Second byte of last
data pair
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