on the inter-linked origins of symbolic computing
and the self-modifying, stored-program computer.
NOTES:
(1) EDVAC vs. Turing, ENIGMA p324 (critical)
(2) IAS instruction set, 20TH, p343
(3) Manchester instruction set, 20TH p436 (only vestiges of ACE, but some vestiges)
WEAK ITEMS TO COVER EXPLICITLY:
Why is there lack of symbolic (eg. character) output in ACE-derived machines?
(viz turing letter to gandy)
Turing's abandonment of higher-level work
As F.C. Williams said, "fast memory is not cheap, and cheap memory is not fast!".
the argument
------------
It's clear today that the innate ability to manipulate arbitrary symbols
is what computers are all about.
Many histories concentrate on the development of the stored-program concept;
clearly it was a critical development, but it only part of the story.
Computers are interesting because they manipulate arbitrary symbols,
not merely because the can do arithmetic;
in fact, numerical computation is a sub-set of symbolic computing.
While this is obvious today, it was anything but obvious
in the mid-1940's when electronic stored program digital computers
came into existence.
The goal of this paper is to show that this now-fundamental concept
was almost completely ignored or misunderstood by nearly all of the
first-generation computers' designer/builders (with one noteworthy
exception) and that it was not widely recognized until electronic stored-program
computers had existed for nearly a decade.
I will also explore the later "discovery" of the usefulness of
logical instructions as they became available in second-generation machines.
To a large degree the stored-program idea was rendered obvioush by the early 1940's;
like many other scientific and technological developments, it occurred to many
people more or less at the same time, because they were all subjected to the same
pressures to solve the same problems, and critical portions appeared in
literature and hardware before the first computers appeared.
The logical structure of the IBM 604 plugboard programming module contains
many of the basic concepts of the stored-program control section and was
referred to as such in the literature [IBM 604, ARITH?]
DROPCAP
The modern vision of the stored-program concept appears to have been first written down
by JvN in [EDVAC REPORT] in 1945,
so he and/or his team frequently get credit for it;
but the idea was well-known by then, though JvN certainly was a major
contributor to this and many other ideas, such as the
one-address machine with central accumulator, a design feature of EDVAC
and it's American offshoots.
JvN himself never claimed ownership of the idea; historical simplification and
a few unfortunate personal agendas create that myth.
By 1944 at least, [CHECK?] the stored-program concept
was obvious enough to those actually working on
calculating/computing machinery; no deep theory was needed,
it was like falling off a chair to anyone with a budget and an engineering team.
[calculator to symbolic]
DROPCAP
Symbolic computing is the manipulation of symbols via machinery,
and the machines that do this we generally call "computers".
As used here, "symbols" includes any abstract representation
within the machinery under discussion, except those interpreted directly as
numbers.
Symbols include the obvious, such as alphabetic text, and the less-obvious,
such floating point arithmetic. (The treatment of
floating point in first-generation computers is a good introduction to the
dilemma of symbolic computing's history; though it is certainly not
arithmetic (as a glance at the complexity of handling zero and signs
in any floating point package will quickly show) and definitely is
symbolic manipulation, few seemed to appreciate this at the time.)
Related to symbolic manipulation is the obvious and stated
ability of a stored-program electronic computer to "modify itself".
Nearly all designs intended as general-purpose automatic, electronic computers
incorporate this explicitly as a design feature as a manner in which a computer
could load a new set of instructions/orders (today, the "program") into it's
main store (though there were a few that used external means of inserting and
extracting data into the main store).
But here too, in this most fundamental design feature, there
were definite ambivalences, implying that computers designers were not fully
comfortable with their constructions.
(It is revisionist to claim that computers are in fact numerical/arithmetical
devices, since all symbolic manipulations in a digital computer are strictly the
rules of boolean algebra; in the late
1930's when all this business started, mathematical logic was an exceedingly
rarefied and "useless" branch of mathematics; it is the very acceptance
of general-purpose digital computers that has made boolean logic so widespread.)
DROPCAP
Simply put, symbolic computing is what we today know computers are for.
I don't mean to make light of the phenomenal and world-transforming mathematical
revolutions brought on by computers, however, their development as
mathematical machinery is far less obscure, and I assert separate from their
originally-unintended use as symbolic manipulators.
It is also obvious that nearly all of the early interest
in electronic computers was for calculating,
largely because complex mathematics was increasingly the limiting
factor in the cutting edge of physics. (It probably
didn't hurt to promote faster calculating machinery to less-than-enlightened
bureaucrats and bean-counters.)
Few in the earliest days of electronic, automatic computing
acknowledged the usefulness of pure symbolic manipulation, if
the knew of it at all. I don't say this lightly; the written record
-- and the machinery left behind -- makes this abundantly clear.
It wasn't until [WHEN] that a significant fraction of computers
included built-in symbolic manipulation in hardware and/or software.
I assert that not only was this not obvious, that very few understood the implications,
and further, that many didn't get it even after it was well-established. And it is no
coincidence that the people who made all of the earliest advances, and in fact the first
operating computers, were the same people who built, out of dire, life-saving need,
machinery that did nothing else but symbolic manipulations, for code-breaking
purposes during the war.
Rather than a my-data-is-bigger-than-your-data argument, I will make my case by
examining the instruction sets ("orders") of machines designed and sometimes
built in the early years, with the assumption that regardless of claims
made at that time or years later, the instruction sets are the embodied
intent of the original machine and therefore its designers.
I will examine the instruction sets of the following machines:
COLOSSUS, built 1943
ENIAC, built 1946; programmable Nov 1947
EDVAC, designed 1946 (no machine named "EDVAC" built)
Turing's ACE, designed 1946
Manchester Baby computer, built 1948
EDSAC, built 1949
Manchester Mark 1 [DATE]
BINAC, built 1950
Pilot ACE, built 1950 (built by Womersley's crowd)
IAS, MANIAC, built 1952 (EDVAC design)
[why these machines]
[filling out the argument, preparing for the analyses of order sets
to be useful to the argument]
DROPCAP
There were two major design paths for automatic, electronic computers by 1946,
JvN's EDVAC ("Electronic Discrete Variable Automatic Computer"), described
in [EDVAC] and published in [DATE]; and
Alan Turing's ACE ("Automatic Computing Engine"), the design published in [ACE] in [DATE].
The stored-program concept was well known by this time to be the
obvious path to follow; F.C. Williams designed and built the SSEM ("Baby")
in record time with what appears to be the explicit goal of being "first",
rather than a useful problem-solving machine, making abundantly clear that
the British knew full well the value of the concept, and possibly it's historical
significance.
DROPCAP
By the time of the EDVAC and ACE reports, in 1946, the British had three years
of making symbol-manipulating machinery at Bletchley Park, doing wartime
cryptographic work. Though most definitely not "computers" in any way,
some of the machines such as the Fish and COLOSSUS machines were programmable
far beyond their original intent [ENIGMA].
Much (but not all) of the Bletchley work was Turing's, who was inducted into
Bletchley based upon his work in logic and his 1936 COMPUTABLE NUMBERS paper,
with its now-famous 'turing machine' logical construction, the machine that emulates
all machines.
Turing was the first to tie theoretical concerns to then-current technology
to define a self-modifying, stored-program computer in the modern sense.
This was implicit in his 1936 paper "ON COMPUTABLE NUMBERS..."[NOTE],
more fully developed in his World War II work on cryptological machinery, and
made explicit at least by 1946, in [ACE].
It is reasonable to assume[FOOTNOTE from ENIGMA; when did Hodges assert
Turing grokked this?] Turing understood this at a much earlier date.
For example, Turing made the explicit and correct statement
that mathematical computing is a subset of symbolic computing
(eg. "floating point arithmetic" isn't arithmetic per se, it is a simulation
of arithmetic's rules with it's own set of behaviours and effects).
It is now obvious why Turing was so clear on the symbolic uses of
computing machinery: his wartime Bletchley Park experiences of designing,
building and operating explicitly symbolic machinery for the purposes of
breaking cryptological character codes. While nothing remotely computer-like
was built then, a number of high-speed, all-electronic logic and arithmetic
machines were built (one of which, COLOSSUS, was capable of a limited
general manipulative ability) that clearly proved that this approach
was a very fruitful one.
DROPCAP
JvN apparently saw stored-program as a means to the
end of fast mathematical machines for other projects, eg. Los Alamos,
at least initially.
All of the early crowd emphasizes mathematical ability for their
machines, most including hardware multiply and divide as a minimum.
However, {EDVAC] report makes not one single mention of use remotely
"symbolic" for his machine; the closest he comes is an immediate dismissal
of sorting[EDVAC p218]. Further, he explicitly describes mechanisms
to prevent a running program from modifying itself[p219]. (Not mentioned
is how programs will get loaded in the first place, but it is extremely
unlikely he overlooked this.) At least by [DATE FROM ARITH] he had
abandoned the M digit separating data ffrom instructions.
JvN certainly knew of Turing's work in general (since he invited him to
work with him at Princeton in [YEAR]), and there is evidence[FROM ENIGMA][FROM 20TH]
that he was aware of his work on [what the hell was he working on pre-ACE?]
While it is possible that JvN was simply too determined in his
mathemetical/hydrodynamical work for Los Alamos to devote any
effort in the direction of symbolic functions, it seems unlikely that
he would have not at least mentioned it in passing.
WHERE DOES THIS BELONG
The British B.P. experience set them as the inheritors of Turing's legacy.
There is no question that British researchers had the first TWO
working computers in the world.
the machines
------------
COLOSSUS, 1943
--------------
Type: special-purpose programmable calculator
Instruction set: "large number" of plugable, random logic gates
Facilities: 5x5 memory (shift register)
501-bit stream generator
Storage: 20 decade counters
http://www.cranfield.ac.uk/ccc/bpark/colossus.htm
A highly-specialized programmable calculator, COLOSSUS had some rudiments of modern
computing, but by no means is it a computer.
It was designed and built under wartime conditions to perform only cryptological
functions (at which it excelled).
Because of the rapidly-changing and often initially-unknown crypto algorithms,
COLOSSUS had to be highly programmable.
It was once "plugged up" to perform multiplications, and other taks far beyond
it's original design requirements.
{ref to performance vs. Pentium-based algorithm; see URL above?]
While it's not a computer in any direct sense it is certain that those
that worked on it or with it gained a massive head-start in understanding the
requirements of a true stored-program computer.
The very existence of the COLOSSUS machines, and therefore their
capabilities, remained secret until the late 1970's [REFERENCE],
and so until relatively recently it wasn't possible to acknowledge their
place in the pre-history of computing.
Furthermore, the British didn't share COLOSSUS-era work with the
Americans, so it remained on their side of the Atlantic.
[COLOSSUS REBUILD]
ENIAC, 1946
-----------
Type: plug-programmable calculator
Instruction set:
Facilities:
Storage: [n] 10-digit decimal numbers
ENIAC was designed and built to be a patch-cord programmable
calculator, but ended up being a true programmable calculator a year later.
It was built to compute ballistic tables fo rth emilitary,
as it's full name, "Electronic Numerical Integrator and Calculator", indicates.
ENIAC was plug-programmable, and had a human-settable function table that
stored constants for calculations. Data in and out was via punched cards.
Like card-calculators before it, it could perform conditional computation,
bsaed upon the sign of an accumulator (eg. stop when minus, etc).
After a November 1947 brilliant modification suggested by JvN, ENIAC became
a true programmable calculator.
JvN's idea consisted of adding a device called simply the "converter",
that translated decimal numbers entered into a large function table
(banks of hundreds of switches arranged in rows, into which numerical
constant tables were entered for calculations) into pulses that
simulated the plugging of patch cords (thereby generating "instructions").
The converter created an added level of abstraction for the programmer/user;
60 order codes, ENIAC's new instruction set, that performed the electrical
equivelant of plugging in patch cords, including a conditional
instruction.
While the added level of abstraction involved in the function table to
plug-cord modifications greatly slowed the operation of the machine,
the order-of-magnitude ease and speed of setup far outweighed any loss.
It also allowed programs to be checked for correctness; the same program
(decimal numbers) could be read in from a stack of punched cards
and the "function table"/program checked for correctness.
(Though it specifically could not load a program from any
source into it's instruction store; hence ENIAC is not a
"stored program" computer, though it is now fully programmable.)
This is almost certainly the first machine with "software" as we know
it today.
JvN's function table::patch cord "hack" is an excellent example of
software abstraction/hardware speed tradeoff (even though the hack is
in fact hardware, it performs a symbolic translation for the users).
Turing's ACE, 1946 (never built)
------------------
Type: Stored-program binary digital computer
Organization: serial
Storage: 6400 32-bit words
register machine [get type name from CPU book]
N address?
32 regs TS1 - 12 special
15 bit addr space
Instruction set: 11 instructions, some sub-modes
Instruction set: ~11 inst., 9 types ACE REPORT (p13, 54)
B branch bit3, lvs PC+1 in reg allows recursion. else type A
K, L, M, N register/data moves
O output to card
P read card
Q CI to TS6 ("acc.")
R logical p61, & | ~ op? =0 rot(n)
S arithmetical (microcoded)
T "microcode"
Facilities:
Storage:
(4) ACE instruction set in Programmers Handbook
Though this machine was never actually built, like von Neumann's
EDSAC design the ACE had a large impact on the soon-to-be-built computers.
It was documented in [ACE REPORT], published the same year as [EDVAC], to which
document the ACE Report refers. However, ACE is not derivative of EDSAC;
further, there is reason to believe [need ref] that JvN and Turing talked about
computer design, not uncommon in the late 1940's. JvN was certainly aware of
Turing's wartime work [ref] [ENIGMA? JvN states he knew of Turing's early work],
in spite of [GOLDSTINE].
Architecturally, ACE is a reasonably "modern" machine, with no major architectural oddities
(if you consider a serial machine not-odd), though there is some juggling of
lower address bits to accomodate memory latency. However, unlike all contemporary
machines, it was a very spare design; the ACE was to be a "software" machine.
At that time, it was considered most
reasonable to arrange that the encoded letter "A" (for instance) on a teleprinter
or punched card be made to correspond, directly, in hardware, to the "ADD" instruction
of the computer. Turing determined, and rightly so, that this was wasteful, and such
things were better done in software.
Rather than a centralized "accumulator" design, Turing designed the arithmetical
elements to be more or less autonomous units, whose functioning ran in parallel with
central control, which made it an extremely fast design.
Turing went much further than this; the ACE Report specifies initial library subroutines
(ACE was capable of reentry and recursion), including a free-form "assembly language".
He makes explicit the conceptual differences between machine language (1's and 0's
contained in memory), relocatable symbolic code (eg. an opcode and a memory reference to
be resolved later) and written, human-readable opcodes, as well as named
variable references and other modern constructs. These ideas were considered
wild, and were not implemented in any first-generation systems.
The ACE design was the only first-generation computer to include logical and bit-manipulation
instructions; for all machines, the emphasis was on mathematics, and nearly all
machines included hardware multiply and divide. The inclusion of logical instructions
(AND, OR, INVERT, etc) was at once far-sighted, and entirely pragmatic -- Turing
realized a decade earlier that all of what a computer could do could be simulated, or
emulated, in a general-purpose symbol-manipulating computer;
and the wartime work at Bletchley Park proved the importance and usefulness of character/symbol
manipulation by machine.
Alas, Turing was his own worst enemy; also in the ACE Report he delved into hardware
design (pedestrian at best, along the way insulting the engineers that might build it) and
scolded his own bureaucratic bosses for cowardice and lack of insight --
not a good way to finesse a difficult project.
Another liability, not his fault, was that the direct experience he
based much of his design on, his wartime cryptological machinery
work, was under extreme secrecy; few could even know what he had worked
on; this made much of his best ideas, based upon years worth of direct
experience in computing, completely opaque, until largely declassified in
the 1970's.
Turing went through a number of versions of the ACE design. The Pilot ACE
was based upon one of his earlier designs, version V. There were further versions
of the ACE design, after the published report.
* Refers to JvN "report on EDVAC
Logical instructions (end sect. 4, p.27)
Photo Pilot ACE, p128, 132+
* cf. Edvac, "risc" order set, do in SW even branch. (prob. from exp w/modding BP machines)
*
EDVAC design, 1946
------------------
Manchester Baby computer, 1948
------------------------------
Type: Stored-program binary digital computer
Instruction set:
Func.| Binary | IEE paper | 'Modern' | Description
No. | code(1)| mnemonic(2)| mnemonic |
--------------------------------------------------------------------------
0 000 s,C JMP Copy content of Store line to CI
1 100 c+s,C JRP Add content of Store line to CI
2 010 -s,A LDN Copy content of Store line,
negated, to accumulator.
3 110 a,S STO Copy content of acc. to Store line.
4 001 a-s, A SUB Subtract content of Store line
from Accumulator
5 101 - - Same as function number 4
6 011 Test CMP Skip next instruction if content
of Accumulator is negative
7 111 Stop STOP Light "Stop" neon
and halt the machine.
Facilities: Umm, none.
Storage: 1024 bits arranged as 32 words of 32 bits each
http://www.computer50.org/index.html
Programmer's reference manual http://www.cs.man.ac.uk/prog98/ssemref.html
This is the world's first true all electronic, stored-program digital computer.
It was essentially designed to be exactly that, and not much more [ENIGMA REF]
by Williams [ENIGMA], who was well aware of the likely milestone. It nonetheless
qualifies, in spite of its just-squeaked-under-the-line features.
Baby is arguably as minimal as can be, and therefore not all that useful
for the task at hand. Its one conditional instruction tests the explicit sign
bit, the simplest possible test in this one's complement machine.
EDSAC, 1949
-----------
Type: Stored-program binary digital computer
Instruction set:
Facilities:
Storage:
BINAC, 1950
-----------
Type: Stored-program binary digital computer
Instruction set:
Facilities:
Storage:
Pilot ACE, 1950 (built by Womersley's crowd)
---------------
Type: Stored-program binary digital computer
Instruction set:
Facilities:
Storage:
EDVAC, 1952 (encompasses IAS, MANIAC machines)
-----------
Type: Stored-program binary digital computer
Instruction set:
Facilities:
Storage:
could not modify instructions until 1947, and for tagged instructions only,
eg. address fields. (1) [Need orig. documents]
Pilot ACE
---------
Storage: Mercury delay line; 300 32-bit words
Version V
See 20TH p111
Though Pilot ACE was a faint shadow of Turing's ACE design, it's basic design
features shown through. Turing's floating point routine code with it's optimum coding
(eg. programming around serial memory latencies) made it nearly as fast as
fixed-point arithmetic; on more conventional machines such as EDSAC, floating
point was considered too slow to be useful.
The autonomous-unit design was kept; for example, though the multiplier unit
didn't handle signs, these could be calculated in software while the multiplier
was working.
The Pilot ACE machine however had it's logical instructions gutted by Womersley,
who originally criticised Turing's design for being "outside the mainstream of
computer design" [find ref in ENIGMA].
MACHINES TO FIND ORDER CODES OF
Baby, 1948
EDSAC, 1949
BINAC, 1949
ERA 1101, 1950
ERA Atlas, 1950
Whirlwind, 1950
UNIVAC 1, 1950
SOURCES
-------------------------------------------------------------
APPENDICES
TIMELINE
NOTE: This needs to include first machines w/logical instructions.
Lop off all extraneous machines!
Atanasoff ABC (not stored?)
On Computable numbers..., Alan Turing, 1937
ENIAC design begun, spring 1943
COLOSSUS, 1943, very programmable, tiny electronic data storage; proto-computer. (secret til late 70s')
"First draft of a report on the EDVAC", JvN, June 1945
WHIRLWIND (digital) design begun, "late 1945" (20TH p 366)
ENIAC, 15 February 1946 demonstration (footnote re: demo vs. first date)
ACE Report [REAL NAME], Alan Turing, early 1946
"Preliminary discussion", JvN, 1946
"Planning and coding", JvN, 1947
ATLAS design begun, August 1947 20TH p490
ENIAC made switch-programmable, November 1947 20TH p459 GOOD DETAIL!
MANIAC design /edvac/ begun, "1948" 20TH p460
Manchester "baby" ("baby MARK I") computer, runs, 21 June 1948 ENIGMA p413, 20TH p433
SWAC design begun /edvac/, May 1948
Pilot ACE design begun, "early 1949" 20TH p108
ORDVAC, ILLIAC design /edvac/ begun, 1949
EDSAC runs, 6 May 1949, first computer in daily service
BINAC, aircraft design, ran Aug 1950, first American computer to run
SWAC dedicated, August 1950
"Computing machinery and intelligence", Turing, October 1950
Pilot ACE, ran on Nov 1950,
ATLAS ran, December 1950, second american machine 20TH p490
EDVAC/Moore School ?
Ferranti Mark 1
IBM 701 design begun, early 1951
MANIAC runs, March 1952
IAS, 1952
ORDVAC delivered, /edvac/ March 1952
ILLIAC delivered, /edvac/ September 1952
IBM 701 delivered, December 1952
DEUCE?
ACE?
Truncated machine list from http://www.digiweb.com/~hansp/ccc/cclist1.htm
1940's. All calculators will be not mentioned
Bletchley Colossus Mark I GB Dec-43 SLa p11
Bletchley Colossus Mark II GB Jun-44 SLa p11
Elliott 152 GB 1947 SLa p57
Elliott 153 GB 1947 SLa p57
Moore School ENIAC USA Dec-47 NCa p190
Birkbeck ARC GB 1948 SLa p62
Manchester University SSEM GB Jun-48 SLa p36
(NSA) DEMON USA Oct-48 AHC v1#1
Bell Labs Model III USA 1949 BW 16
IBM SSEC USA 1949 BW 14
Manchester University Mark I prototype GB Apr-49 SLb p12
Cambridge University EDSAC GB May-49 SLa p29
Eckert-Mauchly BINAC USA Aug-49 NCa p190
Manchester University Mark I GB Oct-49 SLa p40
note: added tomj 20 May 2003
CSIRO (new name) CSIRAC (newer name) AUS Nov 1949
http://www.tip.csiro.au/History/CSIRAC1.htm
Trevor Pearcey
Maston Beard
IBM 607 USA 1950 BW 20
Board of Computing BARK SE 1950
Imperial College ICCE GB 1950 SLa p66
NPL Pilot ACE GB May-50 SLa p45
NBS SEAC USA May-50 NCa p190
SPAC May-50 PAL p332
NBS UCLA SWAC USA Aug-50 EoCS p1465
ERA 1101 aka ATLAS aka USA Dec-50 PAL p332
Machine 13
ERA ATLAS USA Dec-50 AHC V1#1
MIT Whirlwind USA Dec-50 EoCS p332
GE 100 ERMA USA 1951 BW 30
Bull Gamma 2 FR 1951 B&B p740
MESM USSR 1951
Harvard ADEC USA Jan-51 BW 23
Burroughs Lab Calculator USA Jan-51 BW 24
Harvard Mark III aka ? ADEC USA Jan-51 NCa p190
Ferranti Mark I GB Feb-51 SLa p40
Burroughs UDEC USA Feb-51 NCb p234
Eckert-Mauchly UNIVAC I USA Apr-51 NCa p190
CSIRO CSIRAC AU Jun-51 AHC v6#2
Fairchild Computer USA Jun-51 BW 28
Lyons LEO GB Sep-51 PJB p86
U of Toronto UTEC CA Oct-51 AHC V16#2
U of Illinois ORDVAC USA Nov-51 SLa 129
CRC CADAC aka 102 USA Dec-51 SLa 120
RR-409-2R USSR Dec-51 NCb p234
------ untouched list--------------------------------------------------------------
Mathematical Centre ARRA NL 1952 CJ V2#1
Academy of Sciences BESM USSR 1952 WA p91
SEA CUBA FR 1952 AHC V8#4
EMAL PL 1952 AHC V1#1
Bull Gamma 3 FR 1952 B&B p740
M-2 USSR 1952
Zuse Z5 DE 1952 DP V5#3
NCR 102 aka CRC 102 USA Jan-52 NCb p234
IAS IAS USA Jan-52 NCa p190
Los Alamos MANIAC I USA Mar-52 NCa p190
(NSA) ABNER USA Apr-52 AHC V1#1
Moore School EDVAC USA Apr-52 SLa p123
Teleregister Spec Purpose Jun-52 BW 36
Dig Data
Birkbeck APE(R)C GB Jul-52 SLa p63
Harvard Mark IV USA Jul-52 NCb p234
U of Illinois ILLIAC USA Sep-52 NCa p190
Underwood Elecom 100 USA Nov-52 NCa p190
ETL ETL Mk 1 JP Dec-52 CJ V2#3
Elliott NICHOLAS GB Dec-52 SLa p58
1953
NCR 102A USA 1953 BW 46
IBM 604 USA 1953 BW 67
ERA 1103 USA 1953 B&B p854
AN/UJQ-2(YA-1) 1953 BW 58
Mathematical Centre ARRA II NL 1953
Board of Computing BESK SE 1953 WA p91
Elliott ECCLES GB 1953 AHC Oct86
Max Planck Institute G1 DE 1953 CACM 1961
BTM HEC GB 1953 SLa p64
LEM-1 USSR 1953 CS Jun78
Ferranti Mark I* GB 1953 SLa p78
TRE MOSAIC GB 1953 SLa p54
U of Oslo NUSSE NO 1953 CACM 1961
STRELA USSR 1953 BW 109
CRC CRC-105 USA Feb-53 NCa p190
Argonne AVIDAC USA Mar-53 NCa p190
Remington-Rand ERA Logistics USA Mar-53 NCa p190
Monroe Monrobot I USA Mar-53 NCa p190
TRE TREAC USA Mar-53 SLa p117
NCR 107 aka CRC 107 USA Apr-53 NCa p190
Elliott 401 GB Apr-53 SLa p58
IBM 701 USA Apr-53 NCb p234
GE OARAC USA Apr-53 NCa p190
ABC May-53 NCa p190
Consolidated Eng. CEC 36-101 USA May-53 NCa p190
U of Michigan MIDAC USA May-53 NCa p190
NAREC USA May-53 NCb p234
Logistics Research ALWAC II USA Jun-53 BW 40
Raytheon RAYDAC USA Jul-53 SLa p124
MIT Whirlwind II USA Jul-53 BW 45
UC Berkeley CALDIC USA Aug-53 NCa p190
Jacobs Instrument Jaincomp C USA Aug-53 NCa p190
Magnefile Aug-53 NCa p190
Los Alamos MINAC USA Aug-53 NCa p190
Sperry Rand Univac 1103 USA Sep-53 BW 51
FLAC USA Sep-53 NCa p190
Oak Ridge ORACLE USA Sep-53 NCb p234
Dutch PTT PTERA NL Sep-53
Remington-Rand ERA Atlas II aka? 1102 USA Oct-53 AHC v1#1
Manchester University Experimental transistor GB Nov-53 SLa p48
computer
Burroughs UDEC II USA Dec-53 NCb p235
1954
Bell Telephone BE 1954 CACM 1961
IBM 610 Autopoint USA 1954 BW 78
Remington-Rand ERA 1103 USA 1954 AHC v1#1
BTM 1200 GB 1954 SLa p64
Logistics Research ALWAC III USA 1954 BW 79
SEA CAB 2022 FR 1954
CSC-46 AU 1954 BW 72
Hughes DIGITAC USA 1954
Mellon Institute. Digital Computer USA 1954 BW 77
Mathematical Centre for FERTA NL 1954 CJ V2#1
Fokker
Remington-Rand ERA John Plain Mail Order USA 1954 UHN V2#2
Sperry SPEEDAC USA 1954 EM
Bell Labs TRADIC USA 1954 SLa p49
Zuse Z11 DE 1954 DP V5#3
OMIBAC Jan-54 NCb p235
Rand JOHNNIAC USA Mar-54 BW 59
IBM 702 USA Apr-54 DP v2#2
DYSEAC Apr-54 BW 61
Underwood ORDFIAC aka ELECOM 200 USA Apr-54 NCb p234
Underwood Elecom 120 USA May-54 BW 62
Manchester University Mark II (aka MEG) GB May-54 SLa p43
Logistics Research ALWAC USA Jun-54 NCb p235
Nuclear Dev. Ass. CIRCLE USA Jun-54 BW 63
Burroughs B 205 aka Electrodata USA Jul-54 GBD p506
DATATRON
MODAC 5014 IT Jul-54 BW 65
MSI 5014 USSR Jul-54 NCb p235
MSI 5014 USSR Jul-54 NCb p235
Burroughs Electrodata Datatron 204 USA Aug-54 NCb p235
MODAC 404 IT Sep-54 NCb p234
U of Wisconsin WISC USA Sep-54 NCb p235
Fujitsu FACOM-100 JP Oct-54 AHC V2#4
Remington-Rand Univac 60 USA Nov-54 NCb p235
Remington-Rand Univac 120 USA Nov-54 NCb p235
IBM 650 USA Dec-54 NCb p235
MIT Lincoln Labs Memory Test Computer USA Dec-54 BW 69
IBM US Navy NORC USA Dec-54 EoCS p1016
TIM II Dec-54 BW 70
NCR 120D USA 1955 BW 89
Elliott 402 GB 1955 SLa p60
Weapons Research Est ATROPOS aka DIP AU 1955 TP p71
SEA CAB 2000 FR 1955 AHC Oct86
TH Darmstadt DERA DE 1955 CACM 1961
English Electric DEUCE 2 GB 1955 SLa p75
Max Planck Institute G2 DE 1955 CACM 1961
MODAC 410 IT 1955 BW 91
Monroe Monrobot VI USA 1955 BW 90
Ferranti Pegasus GB 1955 SLa p60
TH Munich PERM DE 1955 CACM 1961
International Telemeter TC-1 USA 1955 WA p91
Technitral 180 1955 BW 88
URAL USSR 1955 CJ V3#2
Weizmann Inst WEIZAC IS 1955 CACM 1961
Elliott WREDAC aka 403 GB 1955 DCN v10#3
AERE CADET GB Feb-55 SLa p49
Monroe Monrobot III USA Feb-55 BW 81
CRC 106 aka WHITESAC USA Mar-55 NCb p235
English Electric DEUCE GB Mar-55 SLa p47
Los Alamos MINAC II USA Mar-55 BW 83
Monroe Monrobot V USA Mar-55 BW 84
Manchester University Experimental transistor GB Apr-55 SLa p48
computer Mk II
Remington-Rand AF CRC USA Jun-55 UHN v2#2
Bendix G15 USA Jun-55 NCb p235
Weapons Research Est WREDAC AU Oct-55 TP p43
Logistics Research ALWAC III E USA Nov-55 BW 96
Logistics Research ALWAC III E USA Nov-55 BW 96
RCA BIZMAC I USA Nov-55 CBI 55a
RCA BIZMAC II USA Nov-55 BW 86
Burroughs E 101 USA Nov-55 NCb p235
ETL ETL Mk 2 JP Nov-55 CJ V2#3
Penn State University PENNSTAC USA Nov-55 BW 87
IBM 704 USA Dec-55 NCb p235
Underwood Elecom 125 USA Dec-55 NCb p235
(end 1955)