Friday 6 April 2012

Manual Shift Register

Manual Shift Register(Click photo for Flickr album)

A shift register is a type of integrated circuit used in digital electronics to manipulate information within an electronic system. Shift registers can be found in a diverse range of equipment from washing machines to smartphones.

The Texas Instruments 74HC595 is one such device. It is an 8-bit serial-in, parallel-out shift register – a single input controls eight simultaneous outputs.

The speed at which a 74HC595 operates is controlled by a timer or clock. In a typical application it will execute millions of instructions per second.

The work presented here is a 74HC595 with it's clock and other functions replaced by manual controls. Without intervention the 74HC595 will not operate. Manual Shift Register challenges the orthodoxy of automation in electronic systems. It represents the antithesis of autocorrect - the momentum of the circuit is subjugated to the will of the operator.

A video demonstrating the work follows. Various manual controls determine the input and operation of the device and it's internal state and output are shown using LEDs and a 7-segment display.

Manual Shift Register represents a study towards a larger piece of work applying similar themes and techniques to the construction of an electronic musical instrument. The 29 registers of a MOS Technology 6581 SID chip will be exposed to direct operation using an analogous array of physical controls.

The 6581 is a hybrid digital/analog 3-voice electronic music synthesiser manufactured on a single semiconductor die. It was designed by Bob Yannes for Commodore and used in several of their home computers during the 1980s including the Commodore 64. It's unique sound – so called chiptune or chip music – has become popular with both mainstream and independent artists.