UN230677 UN23/677
UN230678 UN23/678
UN230679 UN23/679
UN230680 UN23/680
UN230681 UN23/681
UN230682 UN23/682
UN230683 UN23/683
DDB 280 Bus, Extender Unit. A pair of these units are used
on the BBC 280 BUS to enable two separate 4 U crates to be
connected together. Each unit can be switched to either
'Master' or 'Slave' mode depending on wh ether it is in the
crate with or without the CPU. The electrical connection
between them is via two 40-way IDC connectors on the front
of the cards. BUS acquisition (i.e. DMA) is possible from
either the 'Master' or 'Slave' crate. They can be used in
systems needing many bus connected units, or for driving
custom hardware from a development system (e.g. SDB-80E).
Power requirements 5V
(provided by the BUS).
unsupported card. DD 1980.
4-Bit Video Storage Logic Unit. This unit differs from the
UN23/642A in that:
1. Higher speed devices are used in certain areas.
2. The data is stored non-inverted.
3. The output shift registers are synchronously loaded.
Power requirements +12V 700mA, +5V 350mA, -5V 35mA. 4U BMM
unsupported card. Supersedes UN23/642A. DD 1980.
Decoder Control Interface Unit. Decoder control interface,
accepts control buses and partly decodes this to provide
control functions for a picture store based on use of
UN27 /504 store boards. Part of the 12, 4, 4 electronic
s tills store system. Coding Positions: 1, 45, 49. Power
requirements +5V, 900mA. 4U BMM Unsupported card. Parent
equipment Electronic stills store, PA1M/580. RD 1981.
Programmable Sync 20-bit Buffer Unit. Programmable
synchronous 20-bit wide data buffer. Provides 2 to 34
words delay as determined by control word. Designed for
12MHz operation. Coding Positions: 1,45,47. Power
requirements +5V, 800mA. 4u BMM unsupported card. Parent
equipment Electronic stills store, PA1M/580. RD 1981.
Delay Logic Unit. Used in television studio communications
system to provide 12 delays, each with open collector
outputs. Printed Circuit Board ll4mm x 254mm, for mounting
in ISEP Chassis. Power requirements +7.5v DC. 114mm x
254mm. SCPD 1981.
Waveform Generator Logic Unit. Contains logic to enah1e
the GE6/540 to generate a waveform identification signal,
also contains part of the identification pulse generator.
Connects to the GE6/540 by a 56-pole connector. Power
requirements +5 V, 90 mA; +12 V, 5 ~A. 47mm x 173mm.
Supersedes UN23/650. Parent equipment GE6/540 GE4M/561.
DD 1981. DDHB 9.187(83).
Digital Field Store Input Control. Generates TTL signals
for the control of Y and UV field stores in the C06/511.
Balanced clock is fed in and buffered to form the write
clocks to the stores, the other store signals generated are
mu1tiplexed write addresses, write enables. The unit has
inputs, sync error, non-sync out, either one of which, when
at a logical 0, will inhibit the write enables and prevent
video data being written into the stores. A switch on the
uni t has the same function. Manual freeze disable input