Monochrome Head-Down Display

Marconi Avionics Limited
H.C.D.U. Mk7
Part 62 D 6202
Ser. No 006
NSN
K0656
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T.&.S.R.L.
Asset No. 175009

HCDU = High Contrast Display Unit

Six general purpose HCDUs were manufactured by the Company Research Laboratory (FARL). These HDDs were based on a design also made for the Airborne Radar Systems Division at Borehamwood. They were intended to support trials programmes as and when the opportunity arose and especially to be compatible with high resolution EO Sensors.

The HDD use a Cathode Ray Tube with a monochrome green phosphor and offer high contrast symbology visible in 10,000ft-Lamberts ambient light. They will accept 625-line video, although two units were modified for 875-line. The twenty function keyboard has ten keys adjacent to the screen so that they can be labelled by on-screen legends. The keyboard interface was a serial data bus to a Panavia specification.

Two of the units were used by ADD for sales demonstrations notably at the Paris Air Show and one was incorporated into a cockpit simulator to study Direct Voice Input. The 875-line units were evaluated by RAE in Puma and Westland Helicopters.

This unit (S/N 006) appears in the Company literature around 1978 and was found in the old Thorn Building.