Radio Shack TRS-80 Model II Reference Manual page 219

Technical Information
Oor 1 or2 (Creation Code). This one-byte field contains a binary number 0, 1
or2.
.
...
CODE
o
2
MEANING
Open the file only if it already exists. Do not create a
new file in directory. Record Length and end of file are
not reset.
Create a new file only; do not Open an existing file.
Record Length and end of file are set at Open time.
Open existing file; if file not found, create i j t t
(rl;'COlrd
length and end of file will be reset).
Table 4.11. File Creation Code
If a new file is being created (creation code
=
lor 2) and the file does not already
exist,
TRSDOS
will use the first write-enabled drive with at least one free granule.
RL (Record Length). This one-byte field specifies the record length to be
used. Zero indicates a record length of256. For Variable Length record files,
this field is ignored. If the file already exists, and the Creation Code is 0, the
System will supply the correct RL value, regardless of what you put there.
"V" or "F" (Variahle or Fixed Length). This one-byte field contains either
an
ASCII
"V" for Variable or an
ASCII
"F" for Fixed. Once a file has been
created, this attribute cannot be changed. If the file already exists, and the
Creation Code is 0, the System will supply the correct "F" or "V" value,
regardless of what you put in the parameter list.
255