English translation — EAI-Mitteilungsblatt Nr. 015

This document is an English translation of the original German publication: EAI Mitteilungsblatt Nr. 015, August 1968 / April 1969, EAI Electronic Associates GmbH, Aachen.

August 1968 / April 1969, No. 015, 5th Year

EAI 7800 Analog/Hybrid Computing System

EAI Germany

In 1969, EAI Electronic Associates GmbH expanded further — not only in personnel but also in terms of its area of responsibility. In addition to the Federal Republic of Germany and West Berlin, Austria and German-speaking Switzerland are now also served. From its Aachen headquarters, EAI GmbH is responsible for sales, customer service, and applications in these territories for all EAI equipment and computers up to the EAI-690 hybrid computing system.

The EAI computers of types 8400, 7800, 8800, 7900, 7945, 8900, 8945, as well as the PACE system, continue to be handled by Electronic Associates, Inc. Division, which also covers the EAI-GmbH’s 1.2 R Exclusive region (up to 116- of West Germany and West Berlin) for multi-channel recorders (Brush), MC-Lab cables, and A. Fischer evaluation equipment.

To introduce the responsible staff members, the engineers’ photographs are grouped around a map showing their respective territories.

Territory I: Dietz Meerkamp, Hartmut Leuschner Territory II: Willy Ahn, Volker Koch, Erwin Roth Territory III: [service territory] Territory IV: [service territory] Territory V: [service territory]

Mr. Roth lives in Munich and is reachable by southern German and Austrian customers at telephone 0811/847272.

Under the leadership of Mr. Ing. Dieter Schwarz, customer service covers all territories from Aachen. The application department of EAI GmbH, managed by Dipl.-Ing. W. Ewert, is available to business customers for specialized technical consultation. The department is also responsible for regularly organized computing courses.

New: EAI 7800 Analog/Hybrid Computing System

1. Vital Statistics

Date of birth: October 1968
Size: 294 computing amplifiers
Special features: High flexibility, ease of operation, 100 V reference voltage

This computer incorporates part of the extremely high operator convenience that is one of the main features of the large-scale EAI 8800. For example, the 42 integrators offer the following control modes, listed in order of priority:

Individual control
Sector control: the components and patchboard are divided into two sectors, each assigned its own repetition timer
Central control of all integrators

The integrators offer selectable time constants of 4, 5, or 6 values (7, 10, 100, 1000 msec, 10 sec, and 0.1 msec) and can be controlled by repetition timers with a range of 10 µsec to 999 seconds.

2. Justification for Existence

The concept of the EAI-7800 analog computer resulted from an extensive customer survey regarding requirements for a new machine. The ratio of performance to cost should be high, at a favorable price for the basic configuration. Most of the surveyed customers have simulation problems requiring 150 to 200 computing amplifiers.

3. Why 100 V?

Many of the application cases mentioned above involve replacing existing 100 V installations with connected devices such as cockpits, where real-time computation predominates. Static accuracy is also very important. It should be noted that the 100 V components were not simply “built in” but had to be developed from scratch; they are not “inherent” to the design.

4. What is New in the EAI-7800?

The computing amplifiers, the nonlinear computing elements, tend toward a “black box” concept — only the inputs and outputs need to be wired; all necessary amplifiers, multipliers, etc. are built in and interconnected. However, for a resolver, different operating modes exist, so this principle is not fully realized — one can speak of a “grey box,” with the necessary switching accomplished via control jacks. The multipliers can similarly be assigned to this category. For the nonlinear elements, low-drift, chopperless differential amplifiers are used.

The computer can be equipped with digital potentiometers. When loaded by a digital computer, this can occur within 10 µsec. Each of these units has a downstream amplifier with a track/store network. This allows set values to be changed without transient oscillations during any operating mode of the computer.

One of EAI’s latest developments is digital function generators, which are also used here.

The EAI-7800 combines a number of new components with components that have proven themselves on the EAI-8800 large-scale analog/hybrid computer.

5. The EAI-7800 as Part of a Hybrid Installation

The entire control system of the computer was adopted from the EAI-8800. This means that: a) The proven standard interface units for digital computers EAI-640 and EAI-8400 (Hand Set Attenuators, Electronic Resolvers) b) The existing hybrid software can be used without modification.

6. Configuration

42 integrators
30 summers (with or without track/store networks)
24 inverters, each with 2 inputs
36 multipliers, each with 2 amplifiers
144 servo potentiometers
24 variable function generators
6 resolvers
36 comparators
Analog-to-Logic Interface, Electronic Multipliers, Logic, Servo Set Attenuators, Digitally Controlled Attenuators (DCA), Function Generators

7. Selected Specifications

a) Summers:

Computing resistor accuracy: ±0.005%
Standard feedback resistor: 1 MΩ
Bandwidth (1 MΩ/1 MΩ): approx. 130 kHz
Bandwidth (100 kΩ/100 kΩ): approx. 800 kHz
Phase shift at 1 kHz: 0.01°
Noise (all-pass): 6 mVpp

b) Integrators:

Integration accuracy: 0.01%
Drift in hold: 50 µV/sec

c) Multipliers:

Bandwidth: 100 kHz
Maximum static error: 0.025% FS
Noise: 10 mVpp
Calibration interval: every 6 months

”Land on the Moon with EAI” — Hannover Trade Fair

At this year’s Hannover Trade Fair, EAI will exhibit in Hall 1, Stand 517. For the first time outside the USA, two new developments will be on display:

The hybrid computing system EAI-7945, consisting of the new analog/hybrid computer EAI-7800 coupled via an interface to the digital computer EAI-640.
The DATAPLOTTER EAI-430, a magnetic-tape-controlled digital high-speed plotting device.

Given EAI’s involvement with NASA (including simulation of moon landings, rendezvous maneuvers, Saturn rocket launches, etc.), the exhibit features a space-related program. A lunar landing will be simulated on the EAI-7945 hybrid system. On a large-screen display, visitors can observe how the spacecraft detaches from its parking orbit around the Moon, sets course for the lunar surface, and finally touches down at zero velocity. Mr. SIM(ulation) — also simulated and visible on screen — will introduce the computing system and provide commentary. Visitors will then be able to try to perform a lunar landing themselves using a control joystick.

PACE System for Chromatography and Mass Spectrometry

At the US Trade Center in Frankfurt am Main, January 20–24, 1969, EAI-Electronic Associates Inc. demonstrated mass spectrometers, residual gas analyzers, and the PACE II computing system for analytical measurement technology.

The PACE II system quickly became the exhibition highlight No. 1.

What is behind PACE? Essentially it is the digital computer EAI-640 with A/D converters and peripherals — a data processing system for modern analytical laboratories that evaluates results from mass spectrometers, fiber testers, auto-analyzers, and up to 40 gas chromatographs.

In Frankfurt, a system for connecting gas chromatographs was demonstrated. A sample of a substance (e.g., an alcohol mixture, approximately 10 µL) is fed to a gas chromatograph (abbreviated GC). Inside, the sample is vaporized. The individual components travel through the entire spiral column but with different transit times. At the GC output, an analog electrical voltage is available as a function of time: it is a distribution function.

Each component — for example, isobutanol — has a discrete, characteristic transit time. The function thus gives the quantity distribution of the individual components. The evaluation of this function is carried out — after analog-to-digital conversion — by the digital computer.

A typical distribution is shown in the illustration. It is visible that at time t = t1, an overlap of two curves (= two components) exists. EAI has developed special software (currently unique worldwide) that makes it possible to cleanly separate such overlaps, i.e., to simulate the course of the individual curves.

(Dipl.-Ing. W. Ewert)

EAI’s Contribution to the World Space Program

As early as 1954, EAI engineers using analog computers successfully charted the path for space flight. Admittedly, it was a dream at the time, but these calculations would play an outstanding role in the greatest scientific achievement of the year 1968.

When Apollo 8, after a lunar flight of 800,000 km, touched down on the water less than 5 km from its target — the aircraft carrier Yorktown — EAI’s “know-how” contributed significantly to the precise landing, using EAI equipment and computers.

In the 14 years between the rocket trajectory work of 1954 and Apollo 8 in 1968, EAI computers and human expertise were deployed in close collaboration for virtually all aspects of the space program: the development of numerous devices; solving control problems; flight trajectory calculations; and thousands of other facets of the enormously complex enterprise — an enterprise requiring the combined efforts of many industrial firms and government agencies.

EAI computers became precise, time-saving tools for numerous contractors and NASA facilities. To date, the company has provided more than $200 million in computers and services to participants in the space and rocket programs.

Since the Apollo program began in 1961, EAI has worked on this project. But even before NASA was founded in 1958, the company was already working at headquarters developing new and better computers and computing techniques to meet the demands of space conditions.

The first Mercury flights and the achievement of, for example, John Glenn in 1962, already demonstrated the use of computer technology co-pioneered by EAI.

As the program advanced, studies were conducted to meet the demand for faster ways to carry out complex operations. NASA, for example, required higher computing speeds without sacrificing accuracy. The precise but relatively slow digital computer was ruled out as an alternative to the fast but less accurate analog computer. EAI’s answer was the development of hybrid systems combining the best features of each technology.

In addition to speed and accuracy, analog/digital computation has a further advantage over digital: in one publication, engineers of a leading American aerospace firm stated the cost of hybrid computation of a lunar launch window at US $25,000 — while the same computation digitally would have required more than one million dollars.

Hybrid systems have long been working on a series of selected, extremely necessary tasks. Walter Schirra, commander of the first Apollo mission, “flew” a hybrid computer in 1963 that was programmed to simulate reentry temperatures.

The more capable EAI computers demonstrated their abilities through simulated space flights in preparation for the 1965 Gemini missions. From this resulted further extensive computer installations at NASA and the industrial firms working with it.

EAI research centers in Princeton, N.J., and Washington, D.C., provided answers over many years to numerous scientific questions. The use of liquid hydrogen-oxygen propellant systems for Saturn launch rockets was recommended; propellant control systems and heat shield problems were solved; jet-propulsion control systems were analyzed.

These were important parts of a monumental whole; each had to work correctly, or complete mission failure was certain. The staff at EAI are understandably proud of their achievements. But it is not surprising that the greatest satisfaction was triggered by the highly successful return of Apollo 8.

“Simulation” is a key word in the vocabulary of aerospace. It is the proving ground for spacecraft. When an automobile manufacturer develops a new model, prototypes are built and tested in use. Component failures, though disappointing, do not lead to great losses of life and material. Even a test pilot in a new model has the safety of an ejection seat and parachute. Not so for astronauts.

Over 1,000 flights of Apollo 8 were successfully conducted without leaving the EAI computing center in Washington, D.C. That is simulation!

Under NASA supervision, a model capsule was constructed. A hybrid system EAI-690, television cameras, a hand joystick, and additional electronics were added. All these units combined created an environment identical to that which the astronauts would see and experience during a normal, computer-controlled reentry and landing phase. But what if the on-board computer fails? The joystick serves as a manual control system. During the practical exercises, various faults were introduced into the guidance system; the human immediately took over control of the capsule.

The EAI-690 also helped locate the spot in the ocean where Apollo 8 would most likely splash down. The Yorktown was positioned at the spot predicted by the computer. Additional recovery units were deployed in the wider area. That the Yorktown was able to recover the astronauts is a historic event. According to NASA officials, it is primarily thanks to EAI’s involvement — through the EAI-690 — that after 800,000 km of flight, a precise landing within a circle of 5 km radius was achieved. That is less than one-thousandth of one percent error. We as television viewers, who watched the return with suspense, can now be certain that the precise landing was neither luck nor coincidence.

(Ing. V. Koch)

EAI 690 Hybrid System — Presentation at the EAI European Hybrid Computing Center

EAI Electronic Associates Inc., European Division 116-120 Rue des Palais, Brussels 3, Belgium

In the past year, several seminars were held at the EAI European Hybrid Computing Center in Brussels on the operation and applications of hybrid computing systems. The strong interest these events generated has prompted EAI to hold another such seminar this year.

Date: Thursday, 19 June and Friday, 20 June 1969.

The two-day seminar will cover both the hardware and software of a hybrid system using the EAI-690 hybrid computing system as the example. Typical application examples will be treated both in theory and through practical demonstrations on the computing system.

EAI 8900 Hybrid Computing System — for England

The photograph shows the final packing operations at end of January 1969 at the delivery factory for the hybrid system EAI-8900, destined for the Central Electricity Generating Board (CEGB) in England. A chartered BOAC jet transport carried the installation from Kennedy Airport to Great Britain. Installation and final testing began immediately upon arrival.

The EAI-8900 hybrid system at CEGB is the largest hybrid system outside the USA. It consists of 3 large analog computers EAI-A-800, the digital computer EAI-8400, a high-performance interface EAI-8930, and peripheral equipment. The installation will be used to simulate complete nuclear power plant networks.

(EAI Press Department)

The EAI-590 Hybrid Computing System

The success of EAI as the most important manufacturer of complete hybrid systems with the EAI-690 and EAI-8900 led to the development of the cost-effective hybrid system EAI-590, which allows the user to build a powerful installation with relatively modest means.

It combines advantages that only a system conceived in its entirety by a single manufacturer can offer: a) A well-balanced system whose individual components are precisely matched to one another, yielding a better price-to-performance ratio than any other hybrid system. b) Complete, proven hybrid software created by a team specializing in analog and hybrid computing systems, capable of continuously supplying customers with further hybrid software as the technology advances. c) The customer deals with only one supplier who assumes full system responsibility and can support in every way.

The system consists of the analog/hybrid computer EAI-580, the digital computer EAI-640, and the hybrid interface EAI-693. The fully developed, mature hybrid software of EAI is included. (In an alternative configuration, the analog/hybrid computer EAI-680 can be used in place of the EAI-580.)

The Analog/Hybrid Computer EAI-580

This computer consolidates both the analog computing components and the programmable parallel logic in a single console. The components are implemented in plug-in module technology, so the computer can be equipped according to available resources and the problems to be solved, with further expansion possible at a later time.

The fully transistorized addressing and readout system, electronic operating-mode control, servo potentiometers, parallel logic, and high computing speed fulfill the requirements for use in a hybrid system. The device is divided into four main sections:

Parallel-organized analog computing components for the simulation and solution of the programmed mathematical model.
Parallel logic components that allow both iterative and repetitive computation as well as control of the analog computing components and program storage.
Analog/Logic Interface components (comparators, function relays, digital/analog switches) for logical control of the analog program and for generating logical signals from analog commands.
Monitoring and control facilities that allow the user to prepare and test the program, read out all components in the 580, and read the program with optional data reduction in the digital computer 640.

Additional key features:

10 V reference voltage
High static and dynamic accuracy
Electronic operating-mode control with individually or group-addressable integrators
Track/store networks with low drift in “hold” state
Easily adjustable variable function generators in drawer modules on the side of the device
Maximum 120 computing amplifiers (bandwidth 400 kHz)
High computing speed (100 µsec to 100 sec)

The Hybrid Interface EAI-693

The hybrid interface EAI-693 is the link between the analog computer 580 (or 680) and the digital computer 640. It contains the units for high-speed data transfer and the monitoring and control functions for the analog computer.

High-speed data transfer is accomplished by: a) Analog-to-digital converters (ADC) b) Sample-and-hold circuits (for sampling and storing signals going to the ADC) c) Digital-to-analog converters (DAC) and/or digital-to-analog multipliers (DAM) d) Synchronization and selection of the respective conversion units

The monitoring and control system enables the digital computer to perform a variety of functions: a) Selection and readout of analog components b) Adjustment of servo potentiometers c) Control of analog operating modes d) Selection of time constants e) Operating-mode control of parallel logic f) Control of function relays g) Readout of comparator outputs h) Readout and control of the digital voltmeter i) Readout of status and error words j) Readout of query lines k) Control of universal interrupts l) Readout of “error” interrupts

The interface system EAI-693 is built in modular design to allow individual customization.

The Digital Computer EAI-640

The third element in the EAI-590 system is the digital computer EAI-640. It has a word length of 16 bits plus memory protection bit, a cycle time of 1.65 µsec, hardwired multiplication, division, and square root. Core memory is expandable from 8 K to 32 K words. Particularly noteworthy is the extremely flexible input/output structure, which is of greatest importance in a hybrid system.

The main tasks of the digital computer in a hybrid system are:

Off-line program preparation and problem setup
Digital data processing from the analog computer (data reduction)
Setup, testing, and readout of the analog computer
Automation of program execution
Closed-loop hybrid computation
On-line communication between the user and the hybrid problem

The Hybrid Software

To fully exploit all the capabilities and advantages of the EAI-590 hybrid system, comprehensive hybrid software is provided:

Problem Preparation: 590 Hybrid FORTRAN; Symbolic Assembler with linkage commands; HYTRAN Operations Interpreter
Setup and Testing: Hardware Diagnostics; HYTRAN Operations Interpreter; 590 Hybrid Debug (error program)
Operation: HYTRAN Operations Interpreter; Hybrid Programming Routines; Function Storage and Playback; Multi-Variable Function Generation

(Dipl.-Ing. D. Meerkamp)

EAI Manufacturing Capabilities

EAI’s manufacturing facilities occupy approximately a quarter million square feet, located in West and North Long Branch, New Jersey; Palo Alto and Santa Ana, California; and Burgess Hill, England. These facilities provide a complete and integrated electronics and electromechanical manufacturing operation for both commercial and military components, subsystems, and systems fabrication.

New: EAI-6200 Digital Voltmeter Expansion Module (Series 6204)

The EAI-6200 Digital Voltmeter can now be expanded into a fully-capable digital multimeter with the addition of new modules. The individual measuring ranges are selected via pushbuttons; the measurement result is displayed digitally on the base unit.

Technical data:

Current measurement: 5 ranges from 100 µA to 1 A full scale; accuracy ±0.14% ±1 digit
Resistance measurement: 8 ranges from 10 Ω to 100 MΩ full scale; accuracy ±0.17% ±1 digit at 100 MΩ (±0.14% ±1 digit at 10 Ω to 10 MΩ)
Automatic decimal point positioning according to selected range
Floating input
Range overload capacity: 40%
Full accuracy over a temperature range of 15–35°C

Modules currently available for the EAI-6200 Digital Voltmeter:

EAI-6201: Integrating digital voltmeter module
EAI-6202: Digital counter module
EAI-6203: AC converter module
EAI-6204: (New) Current/resistance measurement module

(Dipl.-Ing. D. Meerkamp)

European Training and Instruction Program — Calendar 1969

A brochure has been published listing all courses planned for Europe in 1969 (announced in Report No. 14, page 16). Approximately 2,000 copies have already been distributed.

EAI Operating and Programming Courses:

Course	Dates	Location	Language	Cost (DM)
Analog Simulation and Computing	14–16 Jan; 9–13 Jun; 15–19 Sep	Berlin; Burgess Hill	German/English	300–650
Hybrid Computer	17–21 Feb; 3–7 Mar; 10–14 Mar; 24–28 Mar; 2–6 Jun; 7–11 Jul; 22–26 Sep; 13–17 Oct; 17–21 Nov	Burgess Hill; Aachen; Paris; Brussels	English/German/French	640–750
640 Programming	17–21 Mar; 22 Aug–19 Sep; 3–7 Nov	Brussels; Burgess Hill	French/English/German	520
Hybrid Simulation Computing	14–18 Apr; 19–23 May; 29 Sep–3 Oct; 24–28 Nov	Brussels; Burgess Hill	French/English/German/English	880–1000

EAI Maintenance Courses:

Course	Dates	Location	Cost (DM)
380	3–7 Feb; 23–27 Jun; 29 Sep–3 Oct	Burgess Hill	360
680	19–23 May; 21 Jul–1 Aug; 24–28 Sep	Brussels; Burgess Hill	640–1200
640	10–21 Feb; 25 Aug–5 Sep	Brussels	1040
693	24–28 Feb; 6–12 Nov	Brussels	320

New: “DIGIT” Drafting Template

The “Anna” analog drafting template now has a companion — “Digit.” With this new digital template, the drawing and switching symbols of digital computer technology can be quickly sketched. It also allows determining the number of characters per line for a teletype or printer, and the number of lines. A ruler helps determine card count; the edge count allows estimating the number of cards in a package.

Both templates — “Anna” and “Digit” — are available at DM 9.— for the pair, or DM 4.50 each.

(Dipl.-Ing. W. Ewert)

Vehicle Dynamics Simulator at TU Berlin — “No Fear of Analog Computers”

(by Dipl.-Ing. Franz Wallner, Institute for Motor Vehicles, TU Berlin)

At the German Industrial Exhibition in Berlin in autumn of last year, one exhibit attracted special interest: as part of the special show “Quality through Research and Development” (Prof. Dr. E. Fiala), the Institute for Motor Vehicles of TU Berlin demonstrated a vehicle driving simulator.

The simulator, started years ago as a simple experimental setup to investigate the dynamic characteristics of the human as a controller in the vehicle-driver-road system, has grown into a comprehensive installation.

The driver sits in an automobile under a light-tight tent. A television projector projects an image onto a projection screen placed on the hood. The image signal comes from a television camera traveling over a 1:250-scale model landscape illuminated from below. The camera is controlled via servo regulators with DC motors. Vehicle speed, path curvature, drift angle, and roll angle can be perspectively accurately represented. The driver also hears engine and motor noise, tire squealing, and sees the speedometer reading of his speed. At the steering wheel, the driver feels a steering torque controlled by an electrically actuated hydraulic cylinder.

The steering wheel position, accelerator pedal position, and brake pedal force are supplied as electrical voltages to the two analog computers TR-20, which contain the strongly nonlinear dynamic vehicle model built as electrical models. The output voltages of the amplifiers control the drive motors of the model vehicle. The control loop is thus closed.

Initially, it was thought that a desktop computer with 20 amplifiers would suffice for the dynamic vehicle model, but requirements grew over time and even two such computers did not allow the system to be fully exploited unless used in a specific way. In many places, resistors and potentiometers of various values have been added by soldering precision resistors onto plugs as additional input resistors; various nonlinear input and feedback networks were accommodated in blank plug-in modules within the computers. In this way, functions of two independent variables (tire lateral forces as a function of slip angle and braking or driving forces) were implemented at two locations with simple additional networks.

The experience of the simulator — particularly with the analog computers built in without difficulty — has shown that they are not just a good aid to be used without fear, but also that, in the course of the project, one learns to deal with circuits just as one does with cables and plugs around the computing system, maintaining great respect for the analog computers.

Symposium Announcement: Biology, Medicine, and Chemistry Applications

EAI Europe plans to hold a colloquium in the course of the year on application possibilities of analog computers, analog/hybrid computers, and hybrid systems in the fields of Biology, Medicine, and Chemistry.

All interested parties are invited to submit their suggestions. In particular, the following points should be clarified:

Type of presentation
Format: (a) Congress with papers; (b) Seminar with short presentations and ample time for discussion; (a) purely theoretical; (b) with demonstrations; (c) with practical exercises
Location and timing

(Dipl.-Ing. W. Ewert)

Book Announcement: “Analog Computers in Chemistry and Biology — An Introduction”

H. Röpke — J. Riemann
Analog-Computer in Chemie und Biologie — Eine Einführung
Published 1969, Springer Verlag, Berlin-Heidelberg-New York, 184 pages, 198 illustrations, DM 38.—

Dr. Röpke is head of process engineering, Dr. Riemann is a staff member in the main laboratory of Schering AG, Berlin. Both authors worked for a long time with the analog computer TR-20. Since December 1968, a wish of both has been fulfilled — the analog computer TR-48 is now available for the problems that have grown over time.

Preface excerpt:

“The present introduction is directed primarily at those scientists in the fields of chemistry and biology (including border areas) who are interested in the kinetic problems of their subject but who have not yet had practical experience with the analog computer. Students of chemistry and biology, as well as practicing chemists, biologists, pharmacologists, and research physicians dealing with material transformation or transport as a function of time, or other mathematically formulatable processes, are addressed.

Beyond this, the practitioner will find it useful to quickly orient himself using a collection of various basic types of reaction models, so that the recurring preparatory work for model considerations — both for programming effort and for adapting experimental results to specific models — can be reduced to a minimum.

The treatment is confined mainly to application problems. It is shown which problems from chemistry, medicine, and biology can be solved with the analog computer and how one proceeds. Mathematical derivations and apparatus explanations are given only insofar as they are essential for understanding. All questions raised are treated at an elementary level. The discussions aim to introduce or remind, and therefore make no claim to completeness.

For permission to write this book from industrial practice, we thank the board of Schering AG. We wish to express heartfelt thanks to Prof. Dr. E.R. Garrett (University of Florida, Gainesville) for inspiring us in this new working technique.”

Berlin, October 1968
E. Röpke — J. Riemann

EAI 690 Hybrid System — Specification Summary

The EAI-690 hybrid computing system consists of:

EAI-630 Analog/Hybrid Computer (204 computing amplifiers, 10 V machine unit)
EAI-640 Digital Computer (16-bit word, 1.65 µsec cycle time, core memory max. 32 K)
High-performance interface EAI-693 (24 data channels each)

Also available: Analog/Hybrid Computer EAI-380 (54 amplifiers).

EAI Electronic Associates GmbH, 51 Aachen, Bergdriesch 37
Tel. 0241/26041–42, Telex: eai d 832676

EAI Report No. 015 — Newsletter of EAI Electronic Associates GmbH

Newsletter of EAI Electronic Associates GmbH, 51 Aachen, Bergdriesch 37

August 1968 / April 1969, No. 015, 5th Year

EAI 7800 Analog/Hybrid Computing System

EAI Germany

New: EAI 7800 Analog/Hybrid Computing System

1. Vital Statistics

2. Justification for Existence

3. Why 100 V?

4. What is New in the EAI-7800?

5. The EAI-7800 as Part of a Hybrid Installation

6. Configuration

7. Selected Specifications

”Land on the Moon with EAI” — Hannover Trade Fair

PACE System for Chromatography and Mass Spectrometry

EAI’s Contribution to the World Space Program

EAI 690 Hybrid System — Presentation at the EAI European Hybrid Computing Center

EAI 8900 Hybrid Computing System — for England

The EAI-590 Hybrid Computing System

The Analog/Hybrid Computer EAI-580

The Hybrid Interface EAI-693

The Digital Computer EAI-640

The Hybrid Software

EAI Manufacturing Capabilities

New: EAI-6200 Digital Voltmeter Expansion Module (Series 6204)

European Training and Instruction Program — Calendar 1969

New: “DIGIT” Drafting Template

Vehicle Dynamics Simulator at TU Berlin — “No Fear of Analog Computers”

Symposium Announcement: Biology, Medicine, and Chemistry Applications

Book Announcement: “Analog Computers in Chemistry and Biology — An Introduction”

EAI 690 Hybrid System — Specification Summary