README file for Tape Demo
Saturday, March 07, 2015
Author Stan Paddock

Tape Demo is a demonstration program run on the IBM 1401 computer.

The IBM 1401 uses tapes to store large amounts of data.
When processing that data, the each active tape drive would randomly 
be selected and read or write data.

This program makes the tape drives appear to be working very hard.
The program supports the use of one, two or three drives.
When a tape drive is selected, 1 to 9 records are written to the drive.
After a half a reel of tape has been written, the tape drives go into high-speed rewind.

The program uses the IBM 1401 sense switches to control the actions of the program.
SENSE SWITCH A = SHORT TAPE FEATURE (*)
SENSE SWITCH B = TAPE DRIVE  1 ONLY
SENSE SWITCH C = TAPE DRIVES 1 & 2   
SENSE SWITCH D = TAPE DRIVES 1 & 2 & 3  
SENSE SWITCH E = LOOP TEST PROGRAM   
SENSE SWITCH F = TERMINATE PROGRAM  


(*) If the card reader is empty (NPRO), sense switch A  becomes
    just aqnother sense switch.
    If the sense switch A is on with the card reader empty
    the program will only write arount 100 records per loop.
    Then it will rewind the tape(s) and start over.
    This is designed to help test the tape system.
     
The program will terminate with a halt.
If you want to run it again, set sense switch G on, and press start.

If you don’t want to run it again, leave sense switch G off and when you press start, it will look for and read in the next program.