AF8A-351D/27 

AFSA-351 

35 

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03 

In Turn 

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GQH !i'Il*Si·HPIAL 

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TRIP R~PORT -- Visit to Poughkeepsie 

to Inspect TPM 

AFSA-351D 26 December 1951 

f.'ir. Sarnue l 3 • 3ny de z• 

t•ir. Leo W. La. throum 

Mr. Douglas .L. Hogan 

1. IMT.fiODUCTIOI~. On 19 December 1951. the undersigned visited 

the Computer .Laboratories of IBM at Poughkeepsie, IJ. Y., to inspect the IBM 'ltape Processing I•.iacbine. Also pr'3sent for A.FSA was l·iro 

Joseph !~duke of AFSA-221, and, ror A3A, Mro Nathan Disenhaus and ~t. Van Liew. Purpose of our vlsit was to acquire enough additional 

technical information about TPM so that AFSA-~51 can complete its evaluation, in accordance with the recommendation made at the 

meeting called by Mro lt"'riedman on 18 Octobero Dro Werner Buchholtz 

devoted most of the day to an excellent exposition, and was generally 

most cooperative. Mr. Robert w. Murphy was present. and Messrs. 

C. J. Ba.she and R. P. Crago, IBM engineers# assisted in demons~rating 

the equipment. Mr. James Greene of IBM'S engineering staff in 

New York, made arrangements and departed ror New York City after we 

were settled for the technical discussions. Information was obtained 

at the visit as to logical design. nature of overall operation. description of each machine order. operation or electrostatic storage, tentative plans for use of magnetic tapes, and basic times of execution. The status of construction was observed, and size of each 

component was estimated. It was not possible, however. to obtain 

copies of instruction manuals (three volumes are in use, but could 

not be released to us to take out), official promises of delivery 

time. rental cost1 or copies of representative completed programs. However. a complete order code (inclosure) is available from notes 

taken during the visit. together with explanatory material about 

overall :runctioning. This material is on file in AFSA-351D and will 

be available to interested personnelo 

2o PHYSICAL DESCRIPTIONo 

a. 3izea The TPM at present is in prototype form. and is not 

complete enough for testing of all the components. However, it will 

consist of certain pieces of equipment which will be physically the 

same types of units that were observed in various stages of construction. These units were noted. together with estimates of their 

dimensions. The following listing of these units represents only actual floor space of the equipment and does not make allowance for 

suitable operating. storage, and maintenance room normally required for this type of equipment: 

CONFIDENTIAL 

Declassified and approved for release by NSA on 01-27-2014 pursuantto E.O. 1352a 
REF ID:A60185 

Central Computer 

Electrostatic Storage (3 cabo,, total 10,,000 characters) 

Power Supply 

Appr04 .. Dimensions,, 

(Feet) 

8 x 2 

5 x 2 

6 x 2 

l·Iagnetic Drum (10,, 000 characters) (2 )- 5 x 3 

(2 dJ:>Um units,, each 5,,000 characters) 

l.l.ie.gnet1c Tape Drives (4) (4}- 3 x 2 

Appz•ox. 

Area,, 

(Sqa Ft.) 

16 

10 

12 

30 

24 

407-type tabulator 5 x 3 15 

519-type reproducer 5 x 2 10 

TOTAL FLOOR AREA,, EQUIPMENT ONLY••••••••••••••••n•••• 117 sq. ft. 

An estimate vas obtained from one of the I.BM. people that a space of 

about 25' x 30' = 750 sq. ft. vould be required as a minimum operatinB 

area. For purposes or comparison,, it may be worth noting that ABNER 

actual floor area of equipment,, including input-output punch-card equipment,, punched paper tape equipment,, 6 magnetic tape drives,, tvo 

typewriters,, and complete conversion unit,, totals 150 square f"eet,, 

and estimated total operating area assigned to ABNER is ia• x 50' = 

900 sq. rt. ATLAS I equipment area is about 92 sq. rt., with 

approximately 900 square feet assigned to actual operationo 

b. General Appearance and Status or Construction. 

(l) The central computer which contains the control and 

arithmetic circuits is largely comprised of chassis or the type used 

in the IBM 604 Calculator. These chassis contain one tube and its 

associated components all mounted on a miniature tube base. Some of 

the control circuit chassis are of similar construction elongated and containing half a dozen tubes. In front of the central computer is an indicator and control panel1 together with a keyboard for typing in instructions. The wiring or the central computer is similar to 

that seen in the 604. The central computer contains e.bout 2000 vacuum 

tubes and 2800 crystal diodeso The central computer is apparently nearly completed with the exception of covers. 

{2) The electrostatic storage is contained in a separate unit. One rack contains the main deflection and counting circuits 

and four other racks will contain the 10,,000 7-bit characters of 

storage with 100 characters (700 bits}. stored on a 3KP1 cathode ray tube. The 100-cha.racter ''accumulator' ls contained in an additional 

one of these tubes. This accumulator performs no arithmetic .functions 

but merely stores sums. partial products1 and dividends. On the same 

rack vith the accumulator are 12 chassis,, each containing two storage tubes together with reading and writing amplifier circuits. Construction of a prototype set or deflection amplifiers is complete. 

.....,. 1\ ~ I • 2 
.~ . , 

DISPOSITION FORM 

-

AFSA-351D/27 

AFSA-351 

TRIP .REPOR~ ·- Visit to Poughkeepsie 

to Inspect TPM 

FROM AFSA· 351D DAD 26 December 1951 CO.Vd'JKNT 1 

Mr. Samuel s. Snyder Mr. Leo V. Latbroum 

Mr. Douglas L. Hogan 

(3) i'he magnetic drum unit 1a still under construction~ The drum contains fifty tracks. each 700 bits (100 characters) long. The linear packing is 50 to the inch and the peripheral rate is 50 

kc. The sur.face or the drum appears to be CUNIF.E v1re which has 

been machined to a cylindrical surface. The drum is about 4if '' in 

diameter and 7t" long. VeJ!11 little of the reading and writing circuits and not all or the heads appear to have been built. (4~ They have had two magnetic tape un1ta in operation. The tape is 2 " wide and uses 7 levels with linear spacing or 100 

characters per inch. The present tape speed is 30 inches/sec. but 

:Qlans are to have four or more tapo units containing 12" reels 

(3000 f'eet ot tape) and l'Unning at 75 .inches/see. With regard to 

the question ot tape flaws. two views. both l'&ther vague. wel'e 

stated by different people. One stated that untlawed tape (source unspecified) would be used. The other stated that the tape might be spliced and the splice could be ignored. Some tape experimenta- tion appeared to be taking place. 

(5) A modified 519 ~eproducer is being constructed to 

serve as an input and output unit. !his will not necessarily be the 

final design for this purpose. A 407 tabulator .ts being modified 

tor use as an output printer. Both of' these equipments will operate in conjunction v1th revolver storage on the drum to resolve the 

asynchronya Neither appear to be veey tar along. Aa an interim 

device an electric typewriter is being used as an output printer. (6) Commercial power supplJ units are being used with an 

IBM-built distributor panel. The room air 1a air-cond1t1oned and the 

units or the !PM have individual blower ayatema to utilize the room 

air tor cooling. , · (7) When pressed tor an ansver·as to vhen production ot 

the TPM might be expected. none or the ens1neers wanted to s1ve an 

answer. A figure that th' time was or at·leaat the order ot magnitude of' two years,, was vol;unteered by Mr. Crago. To the engineers the 

present equipment is not even a production prototype but atr1ctl7 a 

development project at this time. · ! ... 

3. h'VALUA'IION .FOR AGUCY USE. '"· . · - -. a. 5peedG General purpose computers bt vhioh 'lPM is an example) usually are not directly adaptable to the typo problems that exist in 

quantity at this Agency. However. the speed or theae machines and 

3 

CONFIDENTIAL 
REF ID:A60185 

their ~lexible commands have in several cases made it possible tor 

them to solve many problems of our type in a reasonable time. As 

more specialized orders are added to some ot these machines their 

usefulness has increased. The TPM lacks ·not onl.,. ~the= S'peed but i~n 

many cases the .flex1b111 ty ot 1 ts order code thltt·lliN i'ineoes saey t~ 

make it a suitabl' device tor this Agenc7-J1 ._Fojit.lUXWDpltl-~ lthe simp1e addition or on~ ~~ee-digit~~um'ber to another vill take over a 

millisecond; other opere.tions are also comparably alov. As the 

number of digits increase, so does the time for the O{>eration (t:t\e increase is at th~ .rate or 128 .m1cr0'3ecoJRla per! 1

d!g!tJ1:: Dtl~ td the n~ture or the ma.c~hine, this _time is f'1xetr.'11Jld :oan·!tiot ''tie' :im:Pr<>wdl 1 as would be the. case with mo.at machines v.1th di-u.m ott dthfi:r circura.t-· •' 

ing memo:ry. All qomputers connected w1tti.Lthe Agencyi s_~: this 'time: 

can operate .taste~ .j;~n TPM. The TPM 1BflaOmpared vj,tlt'l'tJ'ieae other 

computers since'in complexity and pb1's1cal size it falls in their 

class. u. : • a:A, c:lle1 ,;o n ::."tI :r;;. .:J J ..... . •. l'; j-1 "', • ., .. • • J\ ./. • '·~ J 

;, . 0 ., ~r.. : : r • · .. ..,. o 1 il".fJ. , · ii:r~-:.-~ouq l c~o :;;;: :i ii er 

b. Programming. Programming for the TPM is like programming .for any computer. Although programming for minimum access time is 

not necessary. or indeed possible~ other machine characteristics 

add to the complexity of programming. For example. the varying length of a unit o.f information (a good feature f'rom the point of view 

of nexibility) makes progroamming much more di.f.ficult than handling 

a standard word length. '!'he order code. which lacks much to ma.ke 

it desirable~ will make the programming of .relatively simple tasks. 

such as alphabetic frequency distributions, false addition or .false subtraction~ much more difficult than in the Agency's existing and 

contemplated digital machines. · 

c. Input-Output. The use of the unput and'.output equipment. particularly tape, is not as flexible as one would desire (or expect) in a machine desinned to process tape. For example,, the requirement 

to rewind a tape to change the function from read to write {and write 

to read) is very z.-estr1ct1ng. . . . 

4. CONCLUDING RE?l.u\HKS • 

a. It is recommended that the Agency reject the proposal to 

rent one or more models of' the Tape Processing Machine. .tor the 

following reasons : , .. · . (l) The TPM is not small in size, will not be soon available, is not easy to program. and in general is not suited to Agency 

use. 

(2) Based upon experience in programming for several 

different computers. and acquaintance with many types or machines in 

different parts or this country and England,, it is safe to say that 

TPM would show up unfavorably,, in comparison with equipment of' comparable size and complexity,, for solutio~ of most Agency ~obs that 

have been considel'Etd for general-purpose computers. · (3) The Agency already has in operation one or the most a reliable electronic computers {ATLAS 1)1 has completed and almost 

r. put into operation a second machine with many specialized cryptanalyt1 ·· features (ABNER),, and is committed to ATLAS II and I~OMAD,, vhich 

represent de.finite fol"Ward steps in car?'YiDS out a f'ar-reaching develo 

4 

I I 
....... . . DISPOSITION ~ REft0Mf1*NifdAt: - - - - 06fifi'ff)Efi'.f !J\L 

5BOtffiiff lNFefiftA:'f ION 

TRIP REPORT -- Visit to Poughkeepsie A.FSA-351D/27 to Inspect TPM 

AF&A-351 FROM AFSA·351D DA~ 26 December 1951 COMMEiiT 1 

Mr. Samuel s. Snyder flaa. Leo W. .Lathzaoum 

Ml'. Douglas L. Hogan 

ment progl'&m on analytic equipment. Fu.rthezamo:re. construction of an ) additional model of both AT.LAS I and ABNER has been recommended by 

the Ceypte.nalyt1c Aids Panel. Operation of such an impressive I 

computer installation represents a tremendous investment bo~h 

financially and in training or technical personnel. To consider . addition of still more computeza equipment which in itself represents J 

a baclcWard step technically and which has not been completed even 

in prototype form. would be unwise. regardless or whether the 

acquisition is by purchase oza by rental fzaom a commezacial concezan. 

b. It is suggested that any eventual reconsi.deration of the 

question of obtaining the TPM satisfy the following :requirements: (1) That pzaograms for typical Agency problems be written 

and time estimates calculated. and compared with programs for otbeza 

equipment. so as to demonstzaate any cases whezae it would be to the 

Agency's benefit to have the TP~; 

(2) It is understood that many characteristics of the 

TPM prototype are subject to radical changes; there.fore the Agency would be wise to wait until the features have been finally determined and a production model observed in operation. before attempt- ing a complete evaluation. 

c. It is considored that from the point of view of the IBM 

Corporation. ve would be rendering IBM a d1ssel'Vice to indicate too 

great an interest in TPI4. Requests toza IBM to expedite pzaoduction 

at this time. be.fore Agency opinion on the ma.chine has had time to 

be made firm. would place an obligation on the Agency to follow 

through with some measure of support. Should the unfavorable :recommendation expressed above become Agency policy. we might have 

caused IBM to make uneconomical deviations in their own production schedule to .respond to such an unwarranted enthusiasm. 

Inclosure: 

TPM List Of Instl'Uctions ... .::; .-? .:r. ; I:)""" '/. -~ /6 ... '\I • -...i.'""~ ,• "''"t ";. c .... DOUGLAS L. HOGAN. 351-B 

Copies buzan1shed: 

AFSA 351B 

3510 

OOT 

206 

22 

5 

CONFlDENTIAt 
REF ID:A60185 e 

Inclosure with/ AFSA-351D/27 

Reset Add 

Reset Subtract 

Add 

TPM -- LIST OF INSTRUCTIONS 

Subtract 

Reset-Add-Reset' 

Add to Memory Store 

Store--Alter Field Marks 

Store--No .Field Marks 

Store--Between Field Marks 

Store--Positive Sign Store--Negative Sign Lengthen 

Shorten 

Set Field Ma.:rks 

Round 

Transfer 

Transfer on Positive Sign Compare 

No Operation Stop 

Multiply 

Divide 

Blank 

Insert Decimal Point 

Asterisk 

Select Tape Write 

Read 

Rewind 

Transfer Except End of File 

Drum