Submitted by: Massachusetts Institute of Technology,

Cambridge, Massachusetts

A general-purpose program for reading, writing, and searching

of magnetic tape. This program was written for the Type

552 Control. It has many advantages over both the standard

DEC routines and also over the DECUS No. 5-40. The routines

are one page long and can be operated with the interrupt on

or off. The DEC program delays the calling program while

waiting for the unit and movement delays to time-out. This

routine returns control to the calling program. This saves 1/4

second every time the tape searches forward and half that

time when it reverses. In addition, it will read and write

block 0. This program is an advantage over the previous

one-page routines in that it allows interrupt operations,

does not overflow by one location, interprets the end zone

correctly and not as an error, and provides a call ing

sequence identical to the DEC program.