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engl. Seite der GE55 aktualisiert

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2        $seiten_id = 'gamma55';
3        $version = '$Id: gamma10.php 278 2012-07-18 12:55:44Z sven $';
4        $title = 'A second generation calculator: BULL GAMMA 55';
6        require "../../lib/technikum29.php";
9        <h2>A second generation calculator: The BULL GAMMA 55 (GE-55)</h2>
11         <div class="box center clear-after">
12                <img src="/shared/photos/rechnertechnik/bull-ge55.jpg" alt="BULL Gamma 55 Computer-Anlage" width="750" height="389" />
13                <div class="bildtext">
14                <p>On the left the printer I41 is visible, in the background the CPU (2m
15wide!) and on the right the paper tape puncher can be seen. On top of
16the desk is a punch card reader with an alphanumeric keyboard in front
17of it.</p>
18                </div>
19                </div>
20        <p>
21        We are since 2012 the proud owners of a new BULL computer system: A BULL Gamma
2255 (also known as GE-55 after the merge with General-Electric). The
23system now in the collection was stored in Switzerland with all
24accompanying documentation, punched cards etc. for 26 years.<br>
26It was developed in 1966 by BULL in France and hit the market in 1967.
27It was aimed at small and middle sized companies that were too small
28as customers for other, larger computer systems.<br><br>
30This computer demonstrates the tremendous advances of computer
31technology in the 1960s. While all instructions on the (larger) Gamma
3210 are implemented with a lot of active circuitry stepping through
33many cycles, this is done in the Gamma 55 by means of a rather large
34read-only-memory. This is an implementation of a microprogram which
35reduces the necessary hardware significantly, making the machine
36cheaper and more reliable.<br>
38The basic implementation of the machines makes heavy use of mechanical
39parts but at least the card reader is an optical device.<br>    <br>
41<div class="desc-left auto-bildbreite borderless no-copyright">
42<a class="popup" href="/shared/photos/rechnertechnik/ge55-offen-1.jpg">
43                <img src="/shared/photos/rechnertechnik/ge55-offen-1.jpg" alt="Während der Restauration" width="319" height="217" /></a>
45                <div class="bildtext"> 
46        <p>The system during the period of restoration of rear view  <a class="popup" href="/shared/photos/rechnertechnik/ge55-offen-1.jpg">enlarge picture</a><br> </p>
47                </div>
48                </div>
50                <div class="desc-left auto-bildbreite borderless no-copyright" style="clear:left">
51<a class="popup" href="/shared/photos/rechnertechnik/ge55-offen-2.jpg">
52                <img src="/shared/photos/rechnertechnik/ge55-offen-2.jpg" alt="Während der Restauration" width="319" height="213" /></a>
54                <div class="bildtext"> 
55        <p>Opened CPU <a class="popup" href="/shared/photos/rechnertechnik/ge55-offen-2.jpg"> enlarge picture</a><br> </p>
56                </div>
57                </div>
61<p>Our machine can be programmed in machine language or some kind of a
62mini-COBOL (Common Business Oriented Language). The compiler is loaded
63via punched cards. To start a program a Supervisor that is loaded by
64punched cards is necessary.<br>
66The system was advertised with 2.5 kB, 5 kB or 10 kB of main memory
67(core memory). Our machine has 5 kB of memory and it is really
68astonishing that a high level language like COBOL - even our
69mini-COBOL - is feasible with such a tiny amount of memory at all.<br><br>
71As an extension a memory drum was offered which also allowed the use of
72a mini-FORTRAN (FORmula TRANslator).<br>
74Although BULL was quite inventive concerning software their hardware
75was quite outdated. The boards used in this machine are the same as
76those in the earlier GAMMA 10 (based on Germanium transistors). At the
77same time other companies like UNIVAC or IBM already employed
78integrated circuits (DTL, Diode-Transistor-Logic) for their machines.<br>
79    </p>
80        <br><br>
81September 2013: <b id="ge-55">Success! The machine is up and running!</b><br>
82After a substantial amount of time spent for debugging, the machine is now
83fully operational again. More the 30 (!!) defective transistors and diodes had to
84be traced down and replaced to achieve this. These parts failed silently
85during the 33 years in storage. We can now proudly state that this is the
86only surviving Gamma 55 on earth which is still running. If you are
87interested in details concerning the architecture and programming of the
88machine, have a look here (in German only): <a href=""> BULL Gamma 55 manuals </a> </p>
90<div class="box left">
91                <a class="popup" href="/shared/photos/rechnertechnik/leser617.jpg">
92                <img src="/shared/photos/rechnertechnik/leser617.jpg" alt="Card-Reader" width="402" height="249" /></a>
93                <div class="bildtext">
94                <p>Card-Reader <a class="popup" href="/shared/photos/rechnertechnik/leser617.jpg">(enlarge picture)</a><br> </p>
95                </div></div>
96The card reader of the GE55 can be seen on the left of the pictures (without
97its cover. It is interesting to see that Bull solved every problem for which
98as (practical) mechanical solution exists in a mechanical way (as compared to
99our times where microcontrollers are abundant even in applications which
100might be implemented more easily with a mechanical approach). The card is
101coupled to a punched tape which generates the clock signal for reading the
102card's columns. Although this part can wear out easily, it is nevertheless an
103ingenious solution.<br>
104Also visible is the projection display: 10 digits and two
105additional symbols are displayed by an array of incandescent lamps with
106associated lenses. This is the main way of communicating with the machine
107like today's video terminals.
108The picture below shows the read-only-memory containing 1024 words. A very
109heavy contraption but very maintainable. (Both pictures can be enlarged by
110clicking on them.)
113                <div class="box right">
114                <a  class="popup" href="/shared/photos/rechnertechnik/ge55-rom.jpg">
115                <img src="/shared/photos/rechnertechnik/ge55-rom.jpg" alt="Read-only-memory" width="399" height="259" /> </a>
116                <div class="bildtext">
117                <p>Right: Read-only-memory removed from the machine.
118 <a  class="popup" href="/shared/photos/rechnertechnik/ge55-rom.jpg">(enlarge picture)</a><br></p>
119                </div>
120                </div>
122        <div class="cols">
123<div class="leftcol">
124<p class="small">Contemporary document: In the following you find some quotations from
125the system description published in 1967/1968:<br>
126<blockquote><p class="small">"After intensive market research, BULL GENERAL ELECTRIC developed a
127versatile computer system: Its internal structure resembles that of
128modern computers. Furthermore it is a data processing system that
129allows direct input via keyboard. It is a real data processing system
130because it can grow with your needs and its memory capacity (internal
131as well as external) can be extended.<br>
133Construction: The central processing unit (CPU) of the GE-55 supports
134four channels; three of which are normal speed channels for slow
135input/output devices and one high speed channel used by external
136memory units or a fast line printer...<br>
137....the cycle time is 7.9 us. Characters are represented by their
138respective ISO-code. The core memory is used as data and program
139memory. A since byte, comprised of 8 data bits and one parity bit,
140stores a single alphabetical character or up to two numerical
143<div class="rightcol"><blockquote><p class="small">
145Instructions are analyzed and executed under control of a
146read-only-memory with a capacity of 1024 word of 36 bits each... This
147memory contains micro programs for control, supervision and execution
148as well as arithmetic and character conversion tables.<br>
150Software: The programming system is mainly comprised of the following
151parts: Symbolic languages that facilitate the actual programming task
152and an assembler for translating assembler programs to machine
156<div class="clear">&nbsp;</div><br>
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