EAI 680 Scientific Computing System - Analog Museum in Schwalbach, Germany

While most modern computing technology is built around zeroes and ones there was a time computers weren’t so binary.

Phenomena in the world aren’t restricted to two states, for example the flow of a liquid or strength of a breeze can be strong or weak and eveything in between.

Analog computers used mechanical motion or the flow of electricity to model these real-world nuances.

Analog computers date back to classical antiquity and the Antikythera mechanism but were still being created well into the 20th century, until digital computers, based on electronic switches, became fast enough for software to replicate their functions.

The Analog Museum in Schwalbach, Germany is packed with rescued and restored analog machines, ranging from a table top analog machine made by the BBC to the EAI 680 Scientific Computing System seen here.

PRS-4 - Muzem Historii Komputerow i Informatyki

The PRS-4 is a modular 16-bit micromputer, the first of which was built in Poland in 1973.

The machines were used to monitor production in the mining industry, show the movement of trains across the railway network and in a variety of research roles. Only 150 of the machines were produced. They were designed to be compatible with a family of microcomputers produced by Hewlett-Packard at the time.

The restored PRS 4 is on show at the Muzem Historii Komputerow i Informatyki (MHKI) in Katowice, Poland.

PDP-8 - Rhode Island Computer Museum

In 1949, an issue of Popular Mechanics magazine contained a prediction that “computers in the future may weigh no more than 1.5 tonnes”. Upon its release in 1963 the Programmed Data Processor (PDP) model 8 made good on that forecast and then some – proving that computers didn’t need to be room-sized monsters that only government and big business could afford.

The PDP-8 was about the size of a fridge-freezer and designed to be cheap compared to the multimillion-dollar price of mainframes at the time – selling for about $18,000. It sold an estimated 50,000 units and its success helped popularise the idea of the minicomputer – relatively low-cost computers that could be housed locally and that didn’t need to be maintained by a team of trained staff.

Compared to a mainframe, the processing power of the US Digital Equipment Corporation machine was limited – only capable of 12-bit processing, compared to the mainframe’s 32-bit processing power. But there were plenty of straightforward tasks like payroll calculation that didn’t require the computing power of a mainframe and demand for the PDP-8 saw minicomputers find a home across a range of industries – turning up in factories, offices, banks and laboratories.

The Rhode Island Computer Museum has restored a variety of PDP machines, including a PDP-8/L, PDP-8/I, PDP-9 and PDP-11/44.

Witch-E project

The Witch, or the Wolverhampton Instrument for Teaching Computing, is the world’s oldest working stored-program electronic computer.

The Witch was based on telephone exchange relays and 900 Dekatron gas-filled tubes, which could each hold a single digit in memory. Paper tape was used to both input data and store the output of the machine.

The machine was built and used by the Atomic Energy Research Establishment in Harwell, Oxfordshire, and went on to be used as a teaching aid at a college in Wolverhampton until 1973.

It was developed to automate laborious mathematical calculations at the Harwell facility. Witch, also known as the Harwell computer, could solve algorithms at roughly the same speed as a single human mathematician using a mechanical calculator.

Witch-E

The WITCH-E project is building an educational replica of the machine that will allow students to learn from the engineering, math, logic, and computing pricinples used to create the WITCH.

Recreating the WITCH as it was is difficult, the machine requires very high voltages to work and many components used in building the original WITCH are no longer available. The WITCH E aims to replace logical component blocks of the original WITCH design with commonly available 7400 series Transitor-Transitor Logic(TTL) components.

Bull Tabulating Machine - Technikum29 Computer History Museum

The Technikum29 Computer History Museum in Frankfurt am Main, in Germany features machines from throughout history.

Exhibits include mechanical calculators, mainframes, punch card equipment and a variety of analog and hybrid analog-digital computers.

The institution aims to restore every device for visitors to use and learn from.

Shown here is a restored Bull tabulating machine from 1954, which the museum can compute the square root of eight-digit decimal numbers. The machine features 1,500 relays and 10 arithmetic units.

Jim Austin Computer Collection

The final nomination is for the Jim Austin Computer Collection, which brings together machines from the early days of computing to the present day.

Each generation of computer is represented, mechanical, relay, valve, transistor, and all the variations of integrated circuit.

Highlights in the collection include various Cray supercomputers, a huge IBM mainframe and one of the largest collections of Digital Equipment Corporation computers.

The collection, started in 1986, is housed in more than 8,000 square feet of buildings in York in the UK.