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File names are compared. A required name will match with an identical name read from cassette tape. Also, required name will match with a longer name read from cassette tape, providing that all the characters match up to and including the last character (i.e. last non-space) of the required name. If a file name read from cassette tape fails to match the required name, the search continues. When a match is found, the NAS-SYS Read command is called to read the file into memory.

The command is terminated after the conclusion of the NAS-SYS Read following a successful file name match. Between entry of the required file name and a successful file name match, the command may be terminated by first stopping the tape and then typing four ESC (SHIFT:ENTER) characters. Four consecutive ESC characters read from the cassette tape input will have the same effect.

AAAA – value to be added to the memory address read from cassette tape. (NAS-SYS 3 only)

This command, along with the ‘w’ command, was one of the earliest routines to be written. The rest of SYS-EX largely grew from here. It is worth mentioning that any file which can be read by the ‘r’ command can also be read by the standard NAS SYS ‘R’ command. Due to the absence of a file name, the reverse of course, is not true.

Search for a tape label

Read a cassette tape and search for a tape label as written by the “l” command. Display the label on the top line of the screen then terminate the command.

The tape drive LED is switched on between entry of the command and command termination. If a tape label is not found, the command may be terminated by first stopping the cassette tape recorder and then typing four ESC (SHIFT:ENTER) characters. Four consecutive ESC characters read from the cassette tape input will have the same effect.

The command may be used for positioning a cassette tape prior to writing a file.

Write to top line of screen

Copies 48 characters to the top line (line 16) of the screen. There are two alternate formats of the command as follows:

1. Copy a line of text from a screen line (1 to 15) to the top line of the screen. The command is entered without any arguments. (i.e. the 8 should be the only character on the line.) The line which is entered following the command line, is duplicated on the top line of the screen.