21 SCIENTIFIC, DATA COMMUNICATING, ELECTRONIC, AUDIO AND VIDEO EQUIPMENT COMPRISING: TELEVISION CAMERA CONTROL SYSTEMS FOR CONVERTING VIDEO SIGNALS WITH INDUSTRIAL PULSES TO EIA STANDARD; PRINTING AND TELEVISING SYSTEMS COMPRISING A MODIFIED TELETYPE PRINTER AND TELEVISION CAMERA; CATHODE RAY CHARACTER GENERATORS; VIDEO CONTROL CENTERS COMPRISING A TELEVISION CAMERA CONTROL, VIDEO SWITCHER AND, OPTIONALLY, A SYNC. GENERATOR; TELEVISION BROADCAST SYNCHRONIZING GENERATORS; TELEVISION CAMERAS; SCREEN SPLITTERS COMPRISING SPECIAL EFFECTS GENERATORS WHICH PERMIT DISPLAY OF TWO PICTURES FROM TWO CAMERAS BY SPLITTING THE DISPLAY SCREEN HORIZONTALLY, VERTICALLY OR DIAGONALLY; VIDEO DISTRIBUTION AMPLIFIERS AND PULSE DISTRIBUTION AMPLIFIERS; VIDEO AUDIO SWITCHERS COMPRISING TERMINATING SWITCHERS, BRIDGING SWITCHERS, PROGRAMMED SWITCHERS, PASSIVE VIDEO SWITCHERS, VIDEO AND AUDIO DISTRIBUTION SWITCHERS, BROADCAST VIDEO SWITCHERS, VERTICAL INTERVAL SWITCHERS AND ROUTING SWITCHERS; VIDEO COLOR ENCODERS; INTERCOM SYSTEMS COMPRISING INTERCOM AMPLIFIERS FOR USE WITH HEADSETS; COMPACT AUDIO/VIDEO STUDIOS FOR USE WITH TELEVISION BROADCAST EQUIPMENT; COMBINED METAL CARRYING CASE AND RACK FOR USE WITH TELEVISION BROADCAST EQUIPMENT; CARD AND PHOTOGRAPH DISPLAYS WITH A TELEVISION CAMERA; FILM AND SLIDE UNIPLEXERS FOR COUPLING A SINGLE FILM OR SLIDE SOURCE TO A TELEVISION CAMERA; ELECTROMECHANICAL PROGRAMMING AND VIDEO SWITCHING EQUIPMENT, INCLUDING CIRCUITRY, WHICH AUTOMATICALLY INTERSPERSE THE OUTPUTS OF TWO OR MORE PROGRAM SOURCES, INCLUDING AUTOMATIC NEWS AND WEATHER TELEVISING EQUIPMENT; COLOR ORIGINATION TELEVISION CIRCUITRY USED TO ADD COLOR INFORMATION TO MONOCHROME TELEVISION TRANSMISSION; AND ELECTRICAL CIRCUIT CONTROL APPARATUS