mpatoray
Experienced Member
We all know about the popularity of the PDP-11 series for your normal run of the mill general business applications, you know program development, accounting and database use. But there where other specialized uses that you may have seen every day and not even realized it.
One of these uses was inn videotape editing. Early videotape editing was a messy affair at first using a razor blade and a microscope to slice and cut out bits and join the tape back together. Or you had early electronic editors that allowed a simple scene insert into a tape.
Then along came the CMX video editing system, a joint venture of CBS and Memorex. The first system the CMX 600/200 was a revolutioin being it was a non linear editor but the cost was prohibitive and relegated the system to network level use.
A later system the 300 was introduced in 1972. The system worked liek this, you took 3/4" U-Matic field source tapes or dubs form studio 2" Quadruplex VTR's, these tapes where used in the edit bay to make the Edit Decision List or EDL, using 2 or 3 desktop U-Matic decks with a special control desk, a switcher and a PDP-11 computer. The editor would mark the edit in and out points and select the transition and the computer would record the selections and create an EDL which would be save to punched tape or floppy disc.
Back in the VTR room the CMX system consisted of a PDP-11 computer, normally an 11/34, a terminal, and input device either paper tape or disc. Now this is where the CMX system is really creative, it used distributed processing. Each VTR had it's own CMX I^2 controller which included its own processing and memory, the controller handled all of the interfacing to run the VTR including reading the cue tracks or SMPTE time code.
These boxes would also control a switcher, audio tape recorders, an automated audio mixer, whatever the station wanted to use. Early systems would control up to 4 VTR's 3 playback and 1 record, but some big production houses modified the system ton accept up to 26 different devices. The controlled devices had all manor of control interfaces, form a simple on off relay for a film telecine, to parallel control for the VTR's and switchers to later serial for VTR's some equipment also included current loop control.
To complete an edit session, the Editor or VTR operator would go retrieve all the media needed for teh edit, Videotape, Film and audio tape, they would then load all the media on the machines, walk over to the PDP-11 insert the EDL tape or disc, enter the load command and then run, and the entire process would take of and run the session. If all the media needed was able to be on the equipment available, no operator intervention was needed during the process. A friend of mine who worked on the system at NBC Burbank said it was a sight to see all of the machines seeking and finding cue points and making the edits.
Of course now most all tape based linear systems have been replaced by non linear editors like Avid and Final Cut Pro.
Matt
One of these uses was inn videotape editing. Early videotape editing was a messy affair at first using a razor blade and a microscope to slice and cut out bits and join the tape back together. Or you had early electronic editors that allowed a simple scene insert into a tape.
Then along came the CMX video editing system, a joint venture of CBS and Memorex. The first system the CMX 600/200 was a revolutioin being it was a non linear editor but the cost was prohibitive and relegated the system to network level use.
A later system the 300 was introduced in 1972. The system worked liek this, you took 3/4" U-Matic field source tapes or dubs form studio 2" Quadruplex VTR's, these tapes where used in the edit bay to make the Edit Decision List or EDL, using 2 or 3 desktop U-Matic decks with a special control desk, a switcher and a PDP-11 computer. The editor would mark the edit in and out points and select the transition and the computer would record the selections and create an EDL which would be save to punched tape or floppy disc.
Back in the VTR room the CMX system consisted of a PDP-11 computer, normally an 11/34, a terminal, and input device either paper tape or disc. Now this is where the CMX system is really creative, it used distributed processing. Each VTR had it's own CMX I^2 controller which included its own processing and memory, the controller handled all of the interfacing to run the VTR including reading the cue tracks or SMPTE time code.
These boxes would also control a switcher, audio tape recorders, an automated audio mixer, whatever the station wanted to use. Early systems would control up to 4 VTR's 3 playback and 1 record, but some big production houses modified the system ton accept up to 26 different devices. The controlled devices had all manor of control interfaces, form a simple on off relay for a film telecine, to parallel control for the VTR's and switchers to later serial for VTR's some equipment also included current loop control.
To complete an edit session, the Editor or VTR operator would go retrieve all the media needed for teh edit, Videotape, Film and audio tape, they would then load all the media on the machines, walk over to the PDP-11 insert the EDL tape or disc, enter the load command and then run, and the entire process would take of and run the session. If all the media needed was able to be on the equipment available, no operator intervention was needed during the process. A friend of mine who worked on the system at NBC Burbank said it was a sight to see all of the machines seeking and finding cue points and making the edits.
Of course now most all tape based linear systems have been replaced by non linear editors like Avid and Final Cut Pro.
Matt
