DACOM MODEL 412 SECUREFAX DIGITAL DOCUMENT FACSIMILE TRANSCEIVER

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP79M00062A000500020008-6
• Release Decision: RIFPUB
• Original Classification: K
• Document Page Count: 10
• Document Creation Date: December 16, 2016
• Document Release Date: September 2, 2004
• Sequence Number: 8
• Content Type: MISC

A proved Release 2004/09/23: CIA-RDP79M 2A000500020008-
L~~ MOD L 4'12 SECUREFAX
Digital Document Facsimile Transceiver
? SUB-MINUTE TRANSMISSIONS
? NON-CONDITIONED VOICE GRADE LINES
? OPERATES OVER DDD NETWORK
? UNATTENDED RECEIVE OPERATION
? SELECTABLE RESOLUTION
? FLAT BED SCANNER
? CONNECTS TO DAA
? CRYPTO INTERFACE
? ELECTROGRAPHIC PRINTER
? EASY TO OPERATE
The Dacom Model 412 is a new and unique facsimile transceiver employing data compression. It has
operating characteristics which collectively surpass any other equipment available today. System features
include digital transmission, high speed, high quality, extensive automation, secure mode, internal paper
supply, adaptively equalized modem, and reasonable cost.
The Model 412 was designed to provide fast transfer of letter size documents between
offices using ordinary telephone lines. The cost per page is approximately the cost of a
special delivery letter.
Installation consists of connecting the unit to a telephone line through a DAA (Data Access Arrangement)
which is furnished by the telephone company and costs only a few dollars a month. For secure com-
munications crypto equipment must be provided. The 412 is supplied with the necessary interface
connections for crypto units.
Any number of 412 transceivers may be connected in a network. The circuits may be WATS
lines, tie lines, private lines, Autovon, microwave, satellite, or simply direct distance dialing
like an ordinary telephone.
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The Dacom Model 412 is a comple operating facsimile transceiver in a co a configuration, based on
advanced state-of-the-art technology throughout. Electronic circuitry has been reduced largely to,LSI/MOS
chips. Digital data compression results in exceptional speed and quality performance characteristics. A
new modem with adaptive equalization permits full speed transmission through switched, non-conditioned
voice grade lines, as well as two way coordination, status, annunciation and control. Verification of receipt
of message is automatic. An electrographic stationary stylus printer produces high contrast copies'on white,
bond like dielectric paper.
The 412 is intended for automatic transmission of most types of graphic forms such as typewritten and
handwritten letters, charts, drawings, sketches, diagrams, and maps in both clear and crypto modes. An
8'/2" X 11" document may be transmitted in less than one minute with a received resolution of 200 lines
per inch in the horizontal dimension and 100 lines per inch vertically. Alternate resolutions available are
200 lines per inch vertically when finer resolution is desired, and 67 lines per inch when speeds in the 30
second range are required. The horizontal resolution is always 200 lines per inch. Pushbuttons on the
console may be used to select resolution, page size, multipage mode or compensate for a noisy line. An
automatic stack feeder (optional), automatic answer and internal paper supply permit operation with a
very minimum of operator attention.
Operation is extremely simple, about the complexity of operating an office copy machine. Place the docu-
mint face down on the console and move it forward to activate the system. Pick up the telephone and
dial the desired number. When an answer tone is heard, hang up the telephone - that's all. The machines
then "handshake" for a few seconds, verifying line conditions, equalizing the modems, and automatically
establishing set-up functions (paper size, resolution, data rate, etc.). The "Transmit" light turns on and the
document moves through the scanner (always in sight), then drops into a tray. After transmission the
light goes out and both machines "hang up". If the "multipage" button has been pushed, the line is held
open so that redialing is unnecessary. "Handshaking" occurs between each document to assure that every
document is transmitted successfully.
At the receive terminal the machine automatically answers, prints the page, deposits it in a tray, informs
the sending station that the document was received and readies itself for the next message. No operator
needs to be present.
Document Size
Communication Line
Line Interface
Secure Mode
Scanner
Copy paper
Power per Terminal
Console Size
Console Weight
Modem Size
Modem Weight
Any size up to 8'/2" wide by 14" long
Voice Grade, switched, non-conditioned line
Interfaces with Data Access Arrangement (DAA)
Complies with MIL-STD-188C (?6 V Polar)
Flat bed, optical, 200 lines per inch
(1,000 ft.) roll, white, dielectric, 8'/2" wide, cut to length, 51/2",
11" or 14"
Average density text, 8'/2" X 11" page:
Vertical Resolution Horizontal Resolution Speed
67 Ipi 200 Ipi 35-45 sec.
100 Ipi 200 Ipi 50-60 sec.
200 Ipi 200 Ipi 1'/2-2 min.
4800/2400 bps adaptively equalized, half duplex (full duplex
optional)
115 VAC, ?10%, 50/60 Hz, 9A, single phase (230 V optional)
Height-39" Width-25" Depth-33"
375 lbs.
Height-5'/4" Width-19" Depth-19'/2"
30 lbs.
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nA
Dacom,lnc., 1060 Morse Ave., Sunnyvale, California 94086 Phone [phone]
 Approved .Release 2004/09/23: CIA-RDP79MOW A000500020008-6
digital-fax
its significance
to the military
F ACSIMILE HAS BEEN used by the military for many
years, but its widespread application, except in
specialized areas, has been amazingly slow in coming.
On a superficial level this is surprising since facsimile
offers the military user a number of unique advantages
of particular importance and usefulness relative to the
military mandate and mission.
Facsimile can minimize the time interval in com-
pleting one of the most vital military communication
by tasks-the delivery of a message for action and im-
Robert S. Meltzer plementation.
Marketing Director The great bulk of written military communica-
tions is accomplished using teletype devices. Teletype
Dacom, Inc. will continue to be used because its vast switched
network is installed and in operation, people know
and how to use it, and it does -the job. However, com-
pared to facsimile, teletype has two basic limitations:
1) It requires a skilled human operator, 2) It cannot
William V. Taylor transmit graphics. The human operator is deficient in
two basic areas: 1) He introduces a time delay be-
Manager Defense Sales cause he is relatively slow, and 2) he makes errors.
Dacom, Inc. Facsimile avoids these problems. The information on
a document requires no further preparation, and hu-
man induced errors are non-existent. Of course, both
teletype and facsimile are subject to communication
line errors or garbling, but a garbled facsimile signal
will not misspell a word or modify the meaning of a
sentence. Not so with teletype.
Optical character recognition (OCR), a relatively
recent arrival, has been used to circumvent the tele-
type problems mentioned above. OCR has the ad-
vantage of phenomenal speed. Errors, while, existent,
can be identified and limited to a certain extent. How-
ever, with OCR another problem is experienced. The
more versatile its reading ability, the greater the com-
REPRfNTED FROM plexity and thus the expense of the terminal equip-
CNAL MAGAZINE ment. A given OCR device is programmed to read
JANUARY/ FEBRUARY 1973 ISSUE a pre-determined variety of letters, numbers and sym-
bols. A character of different shape or size will be re-
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jected. Enlargement of the repWire of readable
characters is possible only at increased cost. In fac-
simile, the information appearing on documents is
scanned microscopically and transmitted regardless of
its design or geometric shape; errors in electronic in-
terpretation do not occur. Furthermore, facsimile is
enormously more flexible than OCR or teletype since
it can convey maps, sketches, drawings, and hand-
written copy in addition to alphanumeric and symbolic
information. Facsimile is fluent in all languages, in-
cluding Japanese, Chinese and others that pose real
problems with conventional communication terminals.
Of course, other types of communication media are
used to move information, such as, mail, courier, tele-
phone and television, but the application distinction
vis-a-vis facsimile are more evident than with teletype
and OCR.
Facsimile has one more advantage over other elec-
tronic means for transmitting messages and docu-
mentary information-it is potentially lower in overall
cost. Simply put, if the cost of operator time, terminal
equipment, line costs, and other communication ex-
penses are taken into account the cost per message
with facsimile will often come out ahead.
With all the advantages cited above, why is it that
facsimile has not played a more prominent role
throughout military communications and not just in
specialized areas? The reason is that facsimile, up to
the present time, has been deficient in a number of
significant areas. A discussion of these deficiencies and
how they have been overcome in newly introduced
digital data compression facsimile equipment is the
subject of this article. While not all the deficiencies
discussed below are concentrated in any one type fac-
simile unit, one or more of these problem areas is
usually found evident in any model examined.
Analog Facsimile
Excessively long transmission time has been one
of the most annoying characteristics of equipment to
date. Most standard facsimile terminals are analog in
design and require approximately six minutes for a
"standard transmission." Since there are a great variety
of modes in which a facsimile unit can operate, one
must be careful to define the assumptions underlying
a stated parameter. When we speak of standard trans-
mission we are referring to transmission of an 81/2 x 11
inch page over a non-conditioned voice grade line
(600-2700 Hz), with a horizontal and vertical resolu-
tion of approximately 100 scan lines per inch which
is adequate for reading typewritten material.
It should be noted that there are units recently
placed on the market which are capable of standard
transmission of three minutes or less. However, it is
the authors' understanding that such units are more
liable to distortions caused by line interference than
the six minute versions, and the most successful ap-
plications have occurred over relatively short distances
or over lines with especially good quality.
The time taken to transmit multiple pages at six
minutes per page causes diversion of line from voice
use for excessive periods, increases communication line
costs, and unduly occupies operator time.
A second pron t obstacle to greater military
use of facsimile is in the area of copy quality. Copy
quality can be viewed by two criteria: 1) line resolu-
tion, and 2) page appearance. The resolution of a
standard transmission is completely satisfactory for
about eight point type or larger (about what one would
find on an ordinary typewritten page). Any smaller
type would often be difficult to read. Telephone page
listings or newspaper baseball scoreboard information
for example would be close to indiscernible. Since a
great deal of printed matter is composed of very small
type, such material simply cannot be successfully con-
veyed by a "standard" analog facsimile transmission.
The other part of the copy quality question is paper
appearance. While much progress has been made in
this area it is fair to say that many of the facsimile
machines operating today utilize paper which is typically
gray, crinkly, limp, difficult to file, and aesthetically
less than pleasing.
Imposition of security provisions have always con-
stituted a non-trivial set of problems for communication
equipment. This is particularly true for facsimile
terminals. Problems have occurred in two areas. The
first has been the degrading effect of processing analog
facsimile signals through crypto equipment. The sec-
ond difficulty has come about in trying to eliminate
the radiation of intelligible radio frequency emissions
from the facsimile terminals. With respect to the ques-
tion of radio frequency emission suppression, the fac-
simile industry has always solved this problem when
required, however, it has most often been done with
a significant cost penalty.
Government encryption equipment is normally digital
in nature. Roughly speaking, the bits of a digital stream
within the crypto equipment are "scrambled" for trans-
mission over the communication line and then put
back in the original bit stream order at the decoding
station. In order to be scrambled, the analog signal
from the facsimile scanner must be converted to a digital
form. Ordinarily, such conversion entails a bandwidth
expansion. If extra bandwidth is not available, such
as when voice grade telephone lines are used, then the
signal must be degraded to some extent. The net result
of this analog to digital conversion process is often
degraded received facsimile copy.
Other factors which have also served to curtail the
use of facsimile within the military, have been lack
of compatibility between facsimile types, manual op-
eration of some models, sensitivity to communication
line interferences, and problems in reliability and
maintenance. It should be again emphasized that the
array of problem areas mentioned above by no means
exists in all machines. However, it should also be stated
that when an attempt has been made with analog
systems to eliminate, or substantially reduce, all of
these limiting characteristics, the resulting terminal
costs have made the use of such units justifiable only
in instances in which expense is not a prime factor.
Digital Data Compression Facsimile
The emergence of secure digital facsimile as a prac-
tical, cost effective medium with features far exceeding
older facsimile designs is the result of the development
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FACSIMILE .....~
GFE
CONSOLE CRYPTO I
L J
MODEM
and practical application of a number of new and ex-
citing technologies. These developments, related di-
rectly to advancements in digital equipment and tech-
niques are:
1. Miniaturization and fabrication of electronic
components employing large scale integration
and metal oxide simi-conductors (LSI/MOS).
2. The development and practical implementation
of extremely efficient data compression algo-
rithms (codes.)
3. The development of high speed modulation/
demodulation devices (modems) capable of op-
erating at low error rates over switched non-
conditioned voice grade lines.
At the same time that these developments have
taken place the whole telecommunications transmission
facility is being converted with increasing rapidity from
analog to digital. Digital facsimile is able to take ad-
vantage of a myriad of performance flexibilities and
cost benefits resulting from the change over.
Description of Digital Facsimile Terminal
The digital data compression system employs the
same basic functional components as analog equip-
ment, with the distinction that digital components and
techniques serve to enhance system performance char-
acteristics.
A scanning device picks up light reflected off the
original document. The signal from the scanning de-
tector is converted into a digital bit stream. The bit
stream is then introduced into the compression cir-
cuitry where a code is applied to reduce the number
of bits necessary to convey the scanned information.
The output of the compressor is directed to the transmit
section of the modem where it is changed into a
modulated carrier for transmission over a conventional
telephone channel. At the receive terminal the com-
plementary functions occur. The digital output of the
modem is expanded in the data reconstructor to its
original bit stream to activate a printing mechanism.
Figure 1 shows a diagram of the functional elements
of a digital facsimile terminal. Note: For secure ap-
plications, a crypto unit is placed between the fac-
simile system and the associated modem as shown.
When operated over the direct distance dialing (DDD)
switched network, a Data Access Arrangement (DAA),
is also employed.
Speed
The combined effect of data compression and high
speed modem technology substantially reduces trans-
mission time. For the "standard" transmission of the
new digital facsimile, a 250 word typewritten message
can be transmitted in less than one minute, or a 600
per cent improvement over the typical analog facsimile
unit in use today.
Note: Such speeds are routinely achieved over
trans-continental distances at modem rates of
4800 bits per second using voice grade DDD
telephone lines.
This increase in speed significantly enhances the
possibility of real time facsimile in many applications.
For example, while previously a ten page plan or report
would require one hour of transmission time, a digital
compression facsimile system takes less than ten min-
utes. The high speed permits visually-aided telephone
conversations at costs far lower than closed circuit TV.
Copy Quality
One of the most useful benefits of digital data com-
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pression, in addition to speed, is its ability to provide
increased resolution with minimum time or bandwidth
penalty. In order to transmit fine line information or
small text, resolutions higher than 100 lines per inch
are needed. If the resolution is increased in an analog
facsimile machine from 100 lines per inch to 200
lines per inch in both horizontal and vertical, the num-
ber of "dots" which must be transmitted increases by
a factor of four. Thus, a six minute transmission at
100 lines per inch would increase to a 24 minute trans-
mission time at 200 lines per inch, over the same tele-
phone channel.
In some digital data compression systems, however,
for reasons which go beyond the scope of this dis-
cussion, time increases only by a factor two. Since
the transmission time is low to begin with, this factor
of two imposes a minimum time penalty. That is, a
one minute transmission at 100 lines per inch becomes
only a two minute transmission at 200 lines per inch.
Thus digital data compression facsimile systems over-
come the severe time limitation imposed when trans-
mission of fine detail is desired. At 200 lines per inch
with transmission times of two minutes or less, pages
with information barely discernible to the human eye
can be transmitted and reproduced legibly. Since
military maps, diagrams, drawings, and printed ma-
terial often contain such fine detail, much more data
can now be successfully transmitted over voice grade
lines in a reasonable time.
Secure Communications
Because the output of the new facsimile systems are
digital in format, they suffer no degradation whatso-
ever when processed through standard government-
furnished encryption equipment. In addition, problems
of interface, synchronization and signal "handshake"
are minimized because both the facsimile and crypto
equipment are of the same digital character.
In the area of meeting government standards for
radio frequency emission, digital circuitry, and LSI
"chips" have a real advantage. The low voltages utilized
have inherently low radiation characteristics. If solid
state or quasi-solid state scanning and printing devices
are used, then the radiation problems are further
minimized. Under ideal circumstances no external
shielding would be required to meet federal standards
for secure operation. One of the severest problems
has thus been set aside if the equipment can be made
to meet federal standards with relative ease.
Flexibility
One of the most impressive characteristics of re-
cently appearing digital facsimile systems is flexibility
of performance and compatibility with other equipment
and systems. The flexibilities include its ability to op-
erate without modification over varying bandwidths,
its ability to operate over digital transmission networks
as well as the normal analog circuits, its compatibility
with store and forward devices, switching systems,
polling, broadcast routines and error correction tech-
niques.
Digital data compression facsimile systems of the
type discussed here are "slaved" from a speed stand-
point to the clock rate provided by the associated
digital modem or an externally provided clock. If the
terminal is required to operate over a narrow band
or low quality channel, the clock rate can be reduced
so that the equipment operates at a low transmission
rate sufficient to communicate without excessive error.
Equipment of this type has been operated for the
U.S. Navy over HF radio links at bit rates as low as
75 bits per second. No degradation of copy quality
occurs even at these low transmission rates and ac-
companying narrow bandwidths.
One of the intriguing applications recently demon-
strated by the Defense Communication Agency (DCA)
is the use of digital facsimile over digital networks such
as AUTODIN. The advantages of operating digital
facsimile over AUTODIN are that first, being a mili-
tary switched network, most recipients of messages
will be near message centers. Also, the network is
secure, and finally, AUTODIN is designed for very
low error rates, so that communication interference
problems occurring on ordinary telephone lines do not
normally occur. Thus problem free reliable transmis-
sion is assured.
Computer Compatibility
The output of a digital facsimile may be stored
on any of the media upon which computer output
is stored. This includes magnetic tape, disc, or solid
state memory. With compression, the efficiency of stor-
age increases in proportion to the compression ratio.
Storing and forwarding of fax messages is similar to
store and forward systems for computer or teletype
data. Other computer oriented functions such as mes-
sage switching, polling of terminals, broadcast trans-
mission, and error correction can be used with digital
facsimile terminals. By employing such operations, a
communication network can compensate for the
variations in communication line loading, and thus
accommodate a greater volume of digital traffic through
the system. The use of these techniques permits much
more economic operation of the network. The digital
facsimile system fits smoothly into the computer-
switched systems which are now being so successfully
applied in many military communication areas.
The military must constantly search for the best,
most advanced, yet cost effective, means available for
accomplishing its vital missions. In the area of facsimile,
newly introduced digital equipment offers to satisfy
this requirement.
Greater resolution and better copy quality provide
a wider diversity and depth of information to the
recipient. This, coupled with a high transmission speed,
results in vastly improved human communications and
decision making. Compatibility with existing computer-
controlled communication systems means that the bene-
fits of these new systems can be readily applied to
facsimile.
Consequently, digital data compression facsimile
equipment may be expected to have wide and rapid
acceptance in military communications.
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se 2004/09/23: CIA-RDP79Mw 2A000500020008-6be l/j G 7 3 p fI
Automatic Dialing Set
o c,
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AUTOMATIC DIALING SET
to call, merely locate desired number
on motorized index, listen for dial tone,
then push t?call" button ...
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 Approved Release 2004/09/23: CIA-
gives your business.
these benefits...
^ SAVES TIME
? Makes telephoning effortless, accurate,
more convenient.
? Easily dials all kinds of.calls -local, long
distance and intercom. -
^ "REMEMBERS" TELEPHONE NUMBERS
? No need to look up numbers-they are
stored on magnetic tape and visibly in-
dexed.
? Numbers may be easily recorded and
changed.
? You avoid the "memory tricks" that some-
times mean delays or wrong numbers.
^ MOTORIZED INDEX
? Permits rapid scanning and fast number
selection.
^ FLEXIBLE CAPACITY
? Individual tape cartridges provide 400 or
1,000 number capacity.
? Several cartridges may be used to give
additional capacity as needed.
? Cartridges are easily and quickly inter-
changeable.
^ OTHER "PLUS" BENEFITS
? Requires little desk space-small, com-
pact.
? Index entries can be quickly made in
pencil.
? Use your telephone in the regular way at
any time.
? No capital investment.
? Prompt, reliable Bell System maintenance
at no extra cost.
? Available in decorator colors.
FOR THE EXECUTIVE, automatic dialing serves as a
valuable "assist" in. accomplishing more. with sub
FOR THE OFFICE WORKER making many outgoing
,calls, helps reduce.fatigue, increase efficiency.
HANDY PLUG-IN DIAL, used to record numbers on, =
magnetic tape, stores in desk drawer or other out-
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 Saves You Time and Effort:
Saves You.Money:
lets you reach
your party quickly
and conveniently without
looking up numbers
or dialing.
speeds call-handling,
boosts staff efficiency
with motorized
index and easy-to-operate
equipment.
Bell System
American Telephone & Telegraph Co.
and Associated Companies
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