- 413 -
UN23
with 33 way connector, pegs 3, 5, 13.
CANCELLED.
DD 1967/69.
UN23/9
Switching Logic Unit used on a digital switching system to
convert indeterminate fleeting pulses from push buttons
into long fixed pulses suitable for feeding a diode
matrix. Also controls push button lamps and other
functions. Related units include UN23/4, UN23/5, UN23/6,
UN23/7, UN23/8, UN20/15. First used with BH-WRT switching
system covered by CDR7l. 33 way ISEP connector, coding
positions 3, 5, 29. DD 1967/69. CANCELLED.
UN23/l0
Lapsed Time Logic Unit used in video tape machines, 1l5V
mains drive, to produce 6V positive going pulses to drive
an electronic clock indicator. CH1/l2. DD 1969.
OBSOLESCENT.
UN23/1l
Lamp Drive Logic Unit used in EPlM/ll to provide current
for lamp illumination on receipt of signals from UN23/9.
Each of the 8 drivers included has a spare gate input for
mass inhibition of lamps for multiple control point
working.
Printed board with 33 way ISEP plug, coding
3,
7, 29. DD 1969/70. CANCELLED.
UN23/l2
Delay Logic Unit used in EPlM/ll at the Broadcasting House
end of the London-Wrotham switching system. Printed board
with
33
way
plug,
coding
3,
11,
17.
DD 1969/70.
CANCELLED.
UN23/l3
Combiner Logic Unit enabling 2 UN20/l5 to operate in
parallel so that either can feed logic to UN23/5 without
mutual interference. Printed board with 25 way connector
to fit PN3A/2l. Coding 3, 15, 17. DD 1969/70.
CANCELLED.
UN23/l4
Buffer Logic Unit required when more than
required in PA2M/9.
PA3A/2l.
DD 1970.
WITHDRAWN.
5 UNl/98 are
DD Spec 2.364.
UN23/17
Logic Data Coder Unit used in
signals and multiplex them into
Printed circuit board with 64 way
OBSOLESCENT.
BAl/4 to encode 32 input
a single binary signal.
G06 connecto'. DD 1972.
UN23/l8
Monitor Control Logic Unit used to act as an interface to
external
commands
and
alarm signals.
Printed
circuit
board with 33 way ISEP plug. DD 1971. OBSOLESCENT.
UN23/20
Clock Synchroniser Logic Unit used to examine a received
bitstream and local clock and produce control signals for
UN23/l9. Also performs framing pattern recognition and
data recovery. Printed circuit board with 33 way ISEP
plug. DD 1971. OBSOLESCENT.
UN23/23
Pulse Stretching Logic Unit used in a digital signalling
system at receiving end to extend the duration of the
reset pulse to a
defined
period.
Printed circuit board
with ISEP 25 way connector, coding 3, 15, 21. DD 1971.

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