Radio Shack TRS-80 Model II Reference Manual page 213

Technical Information
User Notes
1. If you are using the spooler's capture function, the captured data is sent directly
to the capture-file-regardless of what printer control settings are selected. If
you are using the spooler's print function, the printed data will be interpreted
according to the currently selected forms control settings. See SPOOL for details.
2. You can operate with two printers, by switching between the serial and parallel
output modes. One printer can use the automatic control features ofTRSDOS
(auto form feed, etc.), while the other printer is controlled by the program. This
is necessary since only one set ofcontrol counters is maintained.
One possible approach: Select the transparent operation before you switch to the
serial printer and select normal operation before you switch to the parallel printer.
That way, the line and character count will remain accurate for the parallel printer.
It will be up to your program to control the serial printer.
File Access
Supervisor calls described in this section:
Function
Code Name Function
33
LOCATE
Returns the current record 'luMber
34
READNX
Gets next record (Sequential Access).
35
DIRRD Reads specified record (Direct Access).
40
OPEN Sets up access to new or existing file.
41
KILL
Deletes the file from the directory.
42
CLOSE Terminates access to an Open file.
43
WHITNX
Writes next record (Sequential Access).
44
DIRWR
Writes specified record (Direct Access).
47
RENAME
Renames a file.
51
WILD
Compares a file specification
with a wild-card specification.
53
RAMDIR
Gets directory information into RAM.
58
FILPTR Gets pointers of an open file.
Table. 4.10. File Access Calls
249