Around 1900, in Glasgow Scotland, Frederick George Creed developed a keyboard-operated
perforator for preparing morse-code paper tape, to be used for message transmission.
This machine revolutionized the formerly hand-prepared tape process, and he started selling
machines in 1902. Creed went on to develop a receiving perforator, and then a tape-driven
printer which converted morse code into printed characters on paper tape -- the "Creed High
Speed Automatic Printing Telegraphy System."
7P
This is an off line keyboard
perforator, introduced in 1934, whose sole function is to produce
punched paper tape directly from the keyboard input. It may be found
with either 1500 rpm governed or 1450 rpm induction motors. The punch
mechanism is capable of working at up to 140 words per minute, so the
speed of operation is entirely dependent upon the skill of the keyboard
operator. A character counter is often fitted so that the carriage
return and line feed characters may be inserted at the appropriate part
of the text. This is essential if the contents of the tape are to be
printed on a standard page teleprinter.
This machine was
allocated the Post Office reference number "Perforator No. 45".
7TR
This is a non-printing tape
reperforator, introduced in 1931, which uses a number of assemblies
which are common to the model 7 teleprinter. The signal input circuit is
electrically identical to a model 7 teleprinter, and the same range of
motors may be encountered. The later model 7TR/3 punches two tapes
simultaneously. This machine was allocated the Post Office reference
number "Reperforator No. 2".
8 This is the receive only version of the model 7 teleprinter and, hence, is not fitted with a keyboard. It is otherwise identical to the model 7.
25 This is a high speed non printing tape reperforator, introduced in 1955, which operates from a parallel drive at a speed of up to 33 characters per second. The speed of operation is independent of the motor speed, and is determined by the parallel drive circuitry. This machine was usually fitted with a 1500 rpm induction motor operating from 50 Hz AC mains, but 3000 rpm governed motors for DC supplies may sometimes be found. It was designed for use with some of the early electronic computers, and may be found in versions for 5, 6, 7, or 8 unit tape, and with drive voltages from 12 volts to 100 volts DC. It is not normally used for communications purposes, but with suitable drive electronics it can be put to good use.
35 This is a high speed paper tape reader operating at a speed of up to 40 characters per second, in either direction, with a parallel output. The speed of operation is independent of the motor speed, and is determined by the control circuitry. This machine was usually fitted with a 1500 rpm induction motor operating from 50 Hz AC mains. It was designed for use with some of the early electronic computers, and may be found in versions for 5, 6, 7, or 8 unit tape, and with drive voltages from 12 volts to 100 volts DC. It is not normally used for communications purposes, but with suitable drive electronics it can be put to good use.
47
Like the model 3, this
teleprinter also prints on a 3/8" wide gummed paper tape for the Post
Office Telegram service, and was introduced in 1947 to replace the
ageing model 3. The component parts have many similarities with the
model 7, from which it was developed. Like the model 7, a governed motor
was normally fitted. This machine was allocated the Post Office
reference number "Teleprinter No. 11".
54
This page printing teleprinter
was introduced in 1954 as a stop gap measure pending the development of a
totally new teleprinter (the model 75), and is really only an advanced
model 7E in an all enclosing silence cover. This makes it a very nice
machine to operate. Like the model 7 a governed motor was usually
fitted, although some synchronous motors may be found. A tape punch,
operated from the receive mechanism, is often fitted as standard within
the silencing cover. This machine was used as a print out device for
some of the early electronic computers, and may be found coded for some
of the early computer codes.
67
This is a combination of the model
7P keyboard perforator and the model 6S punched tape reader, which was
introduced in 1934. This permits a tape to be punched, and transmitted
directly to line. A governed motor operating at 1500 rpm is normally
fitted, which will permit operation at 45.45 and 50 Bauds. It would be
unusual to find a complete model 67, the majority of which had the
transmitter head removed so that the machine reverted to a standard 7P
keyboard perforator.
71 This is a multiple head punched tape reader with three independent message transmitting heads which was introduced in 1951. It is based on an American design and provides a single current output, not the standard changeover contact found in other Creed machines. It was usually used in message relay stations so that two other messages could be loaded whilst the first was being transmitted. A governed motor is normally fitted, which will permit operation at 45.45 or 50 Bauds. As a tape reader it is physically rather large. This machine was allocated the Post Office reference number "Automatic Transmitter No. 3".
72 This is a multiple head punched tape reader with three independent number transmitting heads to identify the messages being sent by the model 71 tape reader. In all other respects it is very similar to the model 71. This machine was allocated the Post Office reference number "Automatic Transmitter No. 4".
74 This is a multiple head punched tape reader and is a combination of the models 71 and 72, providing one number transmitting head and two message transmitting heads. In all other respects it is very similar to the model 71. This machine was allocated the Post Office reference number "Automatic Transmitter No. 5".
75
When this page printing teleprinter was introduced in 1958, it was the
smallest, lightest, fastest, and most versatile machine in the world. It
utilised a stationary paper platen, and a cylindrical type head which
was driven by a complicated arrangement of levers positioned in response
to the received code. The machine uses one main cam shaft for the
transmit and receive functions, and provides the local copy by internal
mechanical means. When used with the BARTG ST5 terminal unit a very
minor wiring change is necessary to take account of this mechanical
local record. It will operate at 45.45, 50 or 75 Bauds, and may be found
with a dual speed gear box for 45.45 and 50 Bauds, or 50 and 75 Bauds.
If the gear box is not fitted two gears will need to be replaced to
change the operating speed of the machine. The standard motor fitted was
a governed motor operating at 4200 rpm, but some machines were fitted
with 3000 rpm synchronous motors for 50 Hz supplies, or 3600 rpm motors
for 60 Hz supplies. As would be expected, the gears for the different
types of motors are completely different and are not interchangeable.
The various gears for the governed and 3000 rpm synchronous motors,
which have colour coding spots by which they may be identified, are
sometimes seen at rallies, but the gears for the 3600 rpm motors are
extremely rare. Factory fitted options included a paper tape reader
and/or tape punch, automatic carriage return/line feed, dual colour
printing, and a choice of three or four row keyboards. The model 75
could also be supplied as a receive only machine, which could also
fitted with an answer back unit and the associated transmitter contacts.
This machine may also be found coded for some of the early computer
codes, or with a solenoid operated parallel drive mechanism and parallel
output contacts. This parallel drive version may usually be identified
by the 25 way Plessey mark 4 signal connector on the rear of the
machine. A modified version of this machine, which utilised a remote
keyboard for use on the Telex cordless switchboards, was allocated the
Post Office reference number "Teleprinter No. 12".
85 This is a printing reperforator, introduced in 1948, similar to the model 7 page printing teleprinter, but fitted with a perforating unit fitted in place of the paper platen. The perforator is designed to produce "chadless" tape, which means that the holes in the tape are not punched cleanly, but the chads are still attached to the tape by means of a small flap. The text is then printed directly on top of the tape. This style of tape may be read by any of the standard range of punched tape readers. The same range of motors as fitted to the model 7 are also fitted to this machine. This machine was allocated the Post Office reference number "Printing Reperforator No. 1". The receive only version of this machine, the model 85R, was allocated the Post Office reference number "Printing Reperforator No. 2".
86 This is a printing reperforator, similar in most respects to the model 85, but using 7/8" wide tape instead of the standard 11/16" wide tape, and printing the text below the clean punched holes. This tape may be read using the 6S/6 series of tape readers, which are fitted with an adjustable width tape gate. The same range of motors as fitted to the model 7 are also fitted to this machine. This machine was allocated the Post Office reference number "Printing Reperforator No. 1D". The receive only version of this machine, the model 86R, was allocated the Post Office reference number "Printing Reperforator No. 2D".
92 This is an electromagnetically operated punched paper tape reader, introduced in 1957, which operates at speeds up to 20 characters per second with a parallel output. It was designed for use with some of the early electronic computers, and may be found in versions for 5, 6, 7 or 8 unit tape, with drive voltages from 12 volts to 100 volts DC. It is not generally used for communications purposes but with suitable drive electronics it can be put to good use. The mark 1 and mark 2 versions caused very high tape wear, which was corrected in the mark 3 version by redesigning the tape sensing mechanism.
444
This page printing teleprinter was introduced in 1966 to replace the
ageing model 7 in the Telex and private wire services. It was designed
to operate continuously at 75 Bauds, and was only provided with gears
for 50 and 75 Bauds. It was usually fitted with a 3000 rpm synchronous
motor for 50 Hz AC supplies, but a few machines fitted with 3750 rpm
governed motors may be found. Machines for export were sometimes fitted
with 3600 rpm synchronous motors for 60 Hz AC supplies, but these are
now extremely rare. A replacement 45.45 Baud gear for 50 Baud machines
fitted with the 3000 rpm synchronous motor was available from BARTG some
years ago, but the stocks have long since been used up, and there are no
plans to produce any more. This machine is often fitted with a built in
tape punch, a paper tape reader, dual colour printing, and a "stunt box"
for character recognition. It is a very nice machine to operate and, due
to its all enclosing cover, is very quiet in operation. This machine was
allocated the Post Office reference number "Teleprinter No. 15".
750 This page printing teleprinter is a very rare development of the model 75, and uses separate transmit and receive camshafts in a similar manner to other Creed teleprinters. Visually, it is slightly larger than the model 75 in order to accommodate the two camshafts. Very little information is available for this machine, and any intending purchaser should ask for a demonstration of the machine in operation.
2300 This semi-electronic page printing teleprinter, introduced in 1974, was intended as a general replacement for the entirely mechanical model 444 in the Telex and private wire services. However, due to the variety of options available, it eventually became uneconomic to manufacture, and was overtaken by the emerging electronic teleprinters. The timing is crystal controlled, and was normally adjustable for 50, 75 and 100 Bauds. By changing the crystal, operation at 45.45 Bauds is possible. The electronic section contains a number of non standard integrated circuits and, if a serious problem develops, it may prove very difficult to cure. The machine was normally fitted with a 3000 rpm synchronous motor to drive the rotating print head. Characters were printed "on the fly" by a type hammer located behind the paper, without stopping the actual rotation of the print head. This machine was allocated the Post Office reference number "Teleprinter No. 23".
A
Normally means that the machine transmits a 7.5 unit character and
receives in a 7.0 unit cycle; 66 wpm at 50 Bauds. This was the early
transmit and receive configuration, and is not often encountered.
A
When applied to the Post Office versions of the model 70 series of tape
readers it indicates that the transmitter is configured for a 7.42 unit
character.
ASR
Automatic Send Receive. A machine
fitted with a tape punch and tape reader. Often used with the model 444
teleprinter.
B
Normally means that the machine
transmits a 7.5 unit character and receives in a 6.5 unit cycle; 66 wpm
at 50 Bauds. This is the standard transmit and receive configuration.
B
When applied to the Post Office versions of the model 70 series of tape
readers it indicates that the transmitter is configured for a 7.5 unit
character.
C
Normally means that the machine
transmits a 7.0 unit character and receives in a 6.5 unit cycle; 71.4
wpm at 50 Bauds. This was mainly used on private wire circuits.
C
When applied to the Post Office versions of the model 70 series of tape
readers it indicates that the transmitter is configured for a 7.0 unit
character.
CTK
Commercial Typewriter Keyboard.
This was used on the model 7 series of machines so that an ordinary
typist could use a teleprinter without any special training. It is very
complex mechanically, and uses mechanical character storage to
automatically insert the figures and letter shift signals, but is very
easy to use.
D
Normally applied to the model 7
teleprinter to indicate that the machine has been modified for the
Telex service, and that it is fitted with motor on-speed contacts, an
improved answer back unit, and a 33 way signals plug. The machine still
transmits a 7.5 unit character and receives in a 6.5 unit cycle; 66 wpm at 50
Bauds.
D
When applied to the standard
versions of the model 70 series of tape readers it indicates that the
transmitter is configured for a 7.42 unit character.
E Normally
applied to a model 7 teleprinter to indicate that the machine is fitted
with the later overlap cam unit. This cam unit consists of three
separate cam shafts, and allows characters to be printed as soon as
they are received, rather than being printed when the next character is
received as in the earlier versions of the model 7. This cam unit is
fitted as standard to the model 54 teleprinter.
K3 The three row keyboard
used on the model 75 teleprinter.
K4
The four row teleprinter used on
the model 75 teleprinter.
KSR
Keyboard Send Receive. A machine
not fitted with either a tape punch or tape reader. Often used with the
model 444 teleprinter.
M
Fitted with an electro-magnetic
clutch. Applied to the model 6S series of tape readers only.
M3 The
three row keyboard used on the earlier model 7 series of machines. Rather
heavy in operation, but very reliable.
N3 The three row keyboard
used on the later model 7, 47 and 54 series of machines. A very nice
keyboard.
N4
The four row keyboard used on the
later model 7, 47 and 54 series of machines. A very nice keyboard.
P
Fitted with a punched tape perforating attachment which is directly
operated by the action of the keyboard.
PR Printing Reperforator.
A machine which produces punched paper tape directly from the received
signal, and prints the text between the feed holes. Applied to the
model 75 teleprinter only.
R
Receive only version of a
machine. That is, no keyboard or transmitting mechanism is fitted.
RO Receive
Only version of a machine. That is, no keyboard or transmitting
mechanism is fitted. Often used with the model 444 teleprinter.
RP
Fitted with a punched tape reperforating attachment which is operated
directly by the received signal.
T
Fitted with a mechanical punched
taped reader operating via the keyboard transmitting mechanism. Applied
to the model 75 teleprinter only.
Due to the wide variety of equipment which may be encountered, only the standard connections to the Creed machines, which are the ones most likely to be encountered, will be considered.
The standard signalling connector for the majority of Creed machines is the 12 pin Multicon (miniature Jones), with the male plug connected to the machine. An additional connector, the Plessey mark 4 circular connector, was also used on the model 75 series of machines so that the power and signalling leads could be disconnected. The pin designations for the 12 way Plessey mark 4 signal connector are given in the (.) brackets. Some early Creed machines used a large 9 pin, round pin, plug for the signals connections. The pin designations for this 9 pin plug are given in the [.] brackets.
Pin No. Function
1 (A) [6] Mark contact
2 (B) [7] Tongue Note 1
3 (C) [8]
Space contact
4 (D) [9] Receive contact
5 (E) [2] Tongue
6
(F) [1] Send contact
7 (G) [5] Receive electro-magnet Note 2
8
(H) No connection
9 (J) [3] Receive electro-magnet
10 (K) [4]
Bell contact Note 3
11 (L) Bell and Who Are You Contacts Note 4
12 (M) Who Are You contact Note 5
Notes:
1. On the 444 teleprinter, link pin 12 to pin 13 on the 50 way
connector, the other connections remain the same.
2. For "Mark",
current should flow into pin 7 and out of pin 9.
3. This contact
closes when the "Bell" character, figures shift J, is received.
4.
This pin may be bonded to the machine chassis.
5. This contact
closes when the "Who Are You" character, figures shift D, is received.
If the machine is fitted with an Answer Back unit, a 20 character
message will also be transmitted to line.
6. For punched tape
readers, only pins 1 to 6 inclusive apply.
Creed model 75 Teleprinter (cover removed)
Creed model 75 Teleprinter (shown with cover off), a Creed power unit,
Creed output printer/transmitter GP1 ARR3, and a Creed automatic transmitter model 6S/6M.