loaded with a character and a command, Punch Character, is given. This has the effect of setting a DMflag; called the Punch-Request Flag, to a 1. The punching mechanism, sensing the Punch-Request Flag as a 1, proceeds to punch the character.

Fig. PH-2. PMS diagram of RTM Module T(Paper Tape Punch).

When completed with the punching the Punch Request Flag is reset to 0. Another signal is available from the punch, indicating that it is out of paper tape. This signal originates from the closure of a switch contact pair. The Punch Buffer is loaded from the least significant eight. bits of the data Bus. In order to define the operation of the RTM punch control the Teletype punch will be

252