BID/950 HORA BID 950 was basically a replacement for BID 610 and BID 880 types. It is believed that the project was all part of the procurement of the BAe NIMROD AEW aircraft so the machines were initially sponsored by the RAF.
When used in the telegraphic mode, it was the equivalent of an installation of two BID 610 units with a BID 700 (although not compatible with them). It could be used in CTAK or KAK. Also, it was switchable between ITA2 and ITA5 in telegraphic mode with 1, 1.5 or 2 stop bits. There was also a pulse release mode.
In data mode it could communicate with another BID 950 or put into BID 880 mode to work with that machine type. Clocking speeds could be internal or external from the transmit or receive clocks (up to 19.2 kbps) from a DCE device such as a modem.
The BID 950 unit was a standard 19 inch rack type unit about 6 inches high and was modular in construction. There were 6 modules in all. All the modules were removable by undoing four screws at the corner of each module and withdrawing it from the front so maintenance could be carried out without having to take the complete unit out of its rack.
The BID 950 was designed and built by Plessey crypto in Liverpool, UK. Most of the electronics consisted of custom built ICs. There were no field replaceable components and bad modules had to be sent back to the manufacturer. All the connections were on a backplane and of the Amphenol type except one connector on the front for use with a Fill Gun.
Keying material was loaded by using the tape reader on the front of the Fill Gun. One user reports "We only used the tape reader although I did try connecting the gun from a KG84 to the front connector and that worked fine. We used the BID 950 in both telegraphic and data modes and they proved to be quite reliable in service."
Jan 11/10