where M is a unit designation as before. The statement causes the designated unit to be backspaced one logical record of binary information or one physical record of BCD information.
Tape-Checking Procedures
The checking procedures are: EOF, READERR, and WRITERR. These are Boolean procedures.
EOF
An EOF call has the form
EOF (M)
where M is a logical unit designation as before. It yields the value true if the previous read operation encountered an end-of-file or the previous write operation encountered an end-of-tape; otherwise it yields the value false.
An example of the use of an EOF call is:
if EOF(6) then goto ALARM .