Symbolic Device Names

Symbol    Device                                              IOCB

C:        Cassette tape unit                                  #7
D1:-D9:   Disk units 1-9 (number available depends on DOS)  
E:        Screen editor                                       #0
K:        Keyboard                                          
P: (P1:)  Printer                                           
P2:-P8:   Alternate printer; e.g. most parallel are P2:     
R1:-R4:   RS-232 interfaces; requires handler to be loaded  
S:        Screen                                              #6
Z:        R-Time-8 Clock; requires handler to be loaded