for this circuit have been made public by Dan Sandin. The 1445 has also been used by Steve Rutt and Carl Geiger in their synthesizer designs.

All video and analog control signals are interconnected in the Design Device through an electronically switched 32 line signal bus. The output of each module can be delegated to four of 32 bus lines. The inputs to each module can be selected from any one of the 32 lines. A block of eight lines is automatically clamped for video. The remaining 24 lines are fed through amplifiers with manual adjustments for bias and gain. outputs can be additively mixed onto a single line without distortion. Any one input line can be shared by all device inputs, but a device can select only one line per input. A section of the signal bus is shown in figure 2.

The switching system is notated graphically, and programs are written by placing marks at the cross points to be closed. The grap,11"is mounted in front of two 32 x 32 CCD cameras, one for the Output selection and one for the Input selection. Exact registration of the program graphic is determined by use of an alignment oscilloscope shared by the two cameras and driven by their onboard DACs. The outputs from the cameras are distributed along the Design Device backplane. Six lines are distributed in an end to end bus and 160 lines ( 32 for the Input multiplexers and 128 for the Output multiplexers) are individually connected from decoders to discrete 8 wide fet multiplexed switches. The address bus and the decoders can be adapted to be operated by computer to take advantage of computer mass storage, precision timing and algorithm programming. While under direct CCD camera control, switching will take 1/30 of a second and will cause one to two bad video frames. Attached are specifications for the CCD camera tobe used. Figure three is a block diagram of the Input line selection system.

The matrix graph appears on the following page
It would be the "fretboard" of the Graphic Guitar
The frets are read graphically by use of a solid state
sensor, The CROMEMCO Image Sensing Module.