2. The Computer as a Sequencer
Computers first appeared in studios as MIDI sequencers - Atari STs and primitive Apple Macs were used to run early versions of Cubase and Notator (Logics predecessor). These controlled the large arrays of MIDI synths and samplers that either cluttered up the control rooms of the day, or provided a great source of flashing lights, depending on your viewpoint! Their impact on the way that studios worked was minimal - the sounds were either recorded to tape along with the regular tracks, or run in sync and only recorded to the master tape at mixdown. The computer made sequencing quicker and more powerful, with many new creative possibilities, and was widely adopted as a very useful tool.
The piece of hardware that facilitated this revolution was the MIDI interface a box with MIDI ports on it that allowed the connection of MIDI synthesisers and samplers to the computer. As the multitimbrality of these instruments increased, it became desirable for each synth to have its own MIDI port for fully independent control of multiple channels, and so interfaces with up to 8 separate MIDI ports became common - some were even stackable so that power users could use several simultaneously. As the sequencing of MIDI data was all the computer was doing at this stage, it didnt need a soundcard.
Although the computers and MIDI instruments usually worked well in isolation, timing was a common problem. Tape recorders couldnt be relied on to always run at exactly the same speed they were mechanical devices after all, and so continually fluctuated, however slightly. This was not a big problem when purely recording audio - at worst you might experience very slight detuning - however a computers timing is bang-on every time, and the result was that even if you started the tape playback at exactly the right instant, it would gradually drift apart from the computer sequencer. To fix this, some sort of synchronisation was required. The Society of Motion Picture and Television Engineers in the US had created a timecode used to sync audio and film together, and it was this SMPTE (pronounced simp-ty) timecode that solved the problem. SMPTE is a stream of pulses for audio use these are recorded to one of the tracks on a multitrack tape recorder, a process known as striping the tape. The striped tape is then played back through a box that converts it into MIDI Time Code or MTC (the less sophisticated MIDI Clock and Song Pointer system was used in the early days). The sequencer interprets the MTC and is able to keep time by continually adjusting the tempo in line with the pulses.