OPEN UNIT integer NAME filename [WRITE] [UNFORMatted] [READ] [FILE] [FORMatted] [CARD]
The OPEN command is used to open logical units to specific files specified from the input file rather than logical name assignments made prior to the run. This is useful in setting up test cases and interactive use of the program. OPEN can be used to redirect the output that appears on unit 6 to different files by opening unit 6 in the middle of a run. However, it may not be possible to restore unit 6 back on some machines, so be careful with this.