The Two Dials and the Two Hands
The Sony BVE-600 gave the desktop video editor two independent jog dials — one per VCR deck — so the left hand scrubbed the source while the right hand scrubbed the recorder. A physical control surface for time itself, bimanual and symmetrical.
Editing video tape before computers had a grammar that feels alien now. The editor held a reel in one hand and a splice in the other, cut the tape at a literal frame line, and glued the two ends together. A single wrong cut meant splicing back the original piece. The edit was a physical act on a physical object.
The CMX-340, introduced in 1976, replaced that with a keyboard and a single jog knob — the GIZMO, a rotary encoder box you could slide to either side of the keyboard for left- or right-handed editors. Type the edit point, scrub to find the frame, press a button. The edit was a typed command on a computer.
The Sony BVE-600, a desktop U-Matic editing controller from about 1985, took the next step by noticing something obvious once you said it: editing tape involves two decks, so why not give the editor two hands?
The BVE-600 sits between a pair of U-Matic VCRs — one source, one recorder — and presents the editor with two identical jog dials, one for each deck. The left hand scrubs the source footage to find the in point. The right hand scrubs the recorder to find the out point. Both hands work simultaneously, each mirroring the deck it controls, the editor's body mapped onto the two-deck topology of the edit itself.
Each jog dial is a rotary incremental encoder with a spring-loaded shuttle ring. Roll it slowly and the tape steps frame by frame, the picture jittering at the edit point. Roll it faster and the tape shuttles at speed, the audio squawking. Let go and the dial stops, the deck holds. The feel is the feedback — the editor navigates time by touch, watching the two monitors for the image.
This is bimanual interaction in its purest form: two hands, two decks, two independent streams of control, no mode switching, no hand-off. The interface surface is a literal map of the task it serves. Bill Buxton, who studied this class of asymmetric bimanual input at the University of Toronto, would have recognized the BVE-600 as a case study in toolglass thinking before the term existed — the non-dominant hand sets the context (source deck position) while the dominant hand performs the action (recorder position, edit mark).
The BVE-600 was a desktop machine, not a broadcast console. It was Sony's answer for the smaller production house, the corporate video department, the post-production suite that could not afford a full CMX or Grass Valley system. But its interaction model — two independent jog dials, one per hand, one per deck — was the purest expression of the two-deck edit as a physical ritual. The CMX made editing a command. The BVE-600 made it a duet.
The jog dial itself was a quietly influential interface element. The same rotary incremental encoder — roll forward, step frame by frame, the faster you turn the faster it shuttles — later became the scroll wheel on every mouse, the jog wheel on every DJ controller, the scrub wheel on every digital audio workstation. The BVE-600's contribution was to give the editor two of them, one for each hand, and trust that the body knows how to use both.
Today, editing is a timeline on a flat screen, scrubbed with a cursor and a mouse or a trackpad. The jog wheel survives in pro audio and color grading, but the two-handed, two-deck, two-dial symmetry of the BVE-600 is gone — a brief moment when the interface was a physical mirror of the task, and the editor's hands worked the way the machines did.