Colossus & Other Early Computers

Summary

This video from explainingcomputers.com explores historic computers at the National Museum of Computing, UK. It features Colossus, the world's first electronic computer, designed to crack German codes during WWII. The video also showcases the Harwell Dekatron, the world's oldest original working digital computer, and the WITCH, used for computation teaching. The museum's collection includes early PCS, thermionic valves, and large hard disk platters, offering a journey through the evolution of computing.

Takeaways

• 🏛️ The National Museum of Computing is located at Bletchley Park, UK, a site historically significant for its role in code-breaking during World War II.
• 💡 Colossus, the world's first electronic computer, was designed by Tommy Flowers and was instrumental in deciphering encrypted German messages.
• 🔄 Colossus used vacuum tube technology, with the Mark 1 version containing 1,600 tubes and Mark 2 approximately 22,000.
• 🔒 Colossus was not a general-purpose computer; it was specifically designed to break the Lorenz cipher used by the German High Command.
• 🔁 The machine operated on a continuous loop of punched paper tape, capable of processing up to 5,000 characters per second.
• 🛠 Colossus was programmed manually, without an operating system or high-level programming languages, reflecting its specialized purpose.
• 🏗️ A fully working replica of the Colossus Mark I, reconstructed between 1994 and 2017, now stands in its original location at Bletchley Park.
• 🧮 The Harwell Dekatron, the world's oldest original working digital computer, was used for automating mathematical work and emphasized reliability over speed.
• 🔄 The Harwell Dekatron, also known as WITCH, used 828 Dekatron counting tubes for program and data storage and was operational from 1951 to 1973.
• 🛠️ The EDSAC, an early British computer, is being rebuilt at the museum; it was one of the first general-purpose computers and was operational from 1949 to 1958.
• 🏭 The ICL 2966 Mainframe, a large system used by the Tarmac Construction Company until 1999, is also exhibited at the museum, showcasing the progression of computing technology.

Q & A

What is the National Museum of Computing, and where is it located?

The National Museum of Computing is located at Bletchley Park in the United Kingdom, a site famous for its World War II code-breaking activities. The museum showcases many historical computers and is a key place for computing history.

What was the Colossus computer, and what was its significance during World War II?

Colossus was the world's first electronic computer, designed by Tommy Flowers and used during World War II for code-breaking. It was specifically used to help decipher encrypted German high command messages by determining the settings of the Lorenz encryption machine.

How was the Colossus computer programmed?

Colossus was programmed manually by setting switches and plugs on its panels. It had no operating system or high-level programming languages, making it only capable of running the specific applications it was built for, with configurations selected through the switches.

What technology did the Colossus computer use?

Colossus was based on vacuum tube (thermionic valve) technology, with the Mark 1 version having 1,600 vacuum tubes and the Mark 2 version increasing that to 2,200. These components were delicate and needed to remain powered on to prevent them from failing.

What type of input and output system did the Colossus use?

The Colossus computer was fed data through a continuous loop of punched paper tape that circulated around the machine. It could read up to 5,000 characters per second. Its output was directed to an electric typewriter rather than a monitor or display.

What is significant about the Harwell Dekatron computer?

The Harwell Dekatron is the world's oldest original working digital computer. It was built to automate mathematical tasks and prioritized simplicity and reliability. It used 828 Dekatron counting tubes for program and data storage and operated from 1951 until 1973.

What was the purpose of the Harwell Dekatron, and how did it compare to human performance?

The Harwell Dekatron was built to automate mathematical tasks. It was not much faster than a skilled human mathematician, but it could work for long periods without getting tired, offering reliability over speed.

What is EDSAC, and why is it important?

EDSAC (Electronic Delay Storage Automatic Calculator) was one of the first computers designed for general use by people who did not build it. It ran its first program in 1949 and was essential in scientific research, with some Cambridge scientists even winning Nobel Prizes for work that relied on EDSAC calculations.

What is the ICL 2966 Mainframe, and when was it built?

The ICL 2966 Mainframe was constructed between 1985 and 1987 by International Computers Limited (ICL), a major British computing company. It was used until 1999 by the Tarmac Construction Company and was decommissioned due to concerns over the Y2K problem.

What are some of the other exhibits at the National Museum of Computing?

In addition to Colossus, EDSAC, and the Harwell Dekatron, the museum features other large computing systems, thermionic valves, early hard disk platters, and early personal computers. These exhibits showcase the history and development of computing technology.

Outlines

00:00

💻 A Look at Historic Computers at Bletchley Park

The video begins by introducing the National Museum of Computing at Bletchley Park in the UK, a former World War II codebreaking facility. One of the highlights is Colossus, the world’s first electronic computer, built by Tommy Flowers in 1944. Colossus helped break German high-command messages using the Lorenz cipher machine. Although programmable, Colossus is not a general-purpose computer and lacks modern features like RAM. It operates using vacuum tubes and punched paper tape, processing up to 5,000 characters per second.

05:02

🖥️ Colossus: Rebuilding the Legendary Codebreaker

The video continues by explaining how the Colossus machine works, including its vacuum tube-based technology and paper tape input. It describes how Colossus is programmed via manual switches and plugs, lacking any high-level programming languages or operating system. The specific machine in the video is a rebuild of Colossus Mark I, completed in 2017 at the same location in Bletchley Park, led by Tony Sale. The narrator emphasizes how impressive the recreation is, both in terms of its mechanical design and historical significance.

🔢 Harwell Dekatron: The Oldest Working Digital Computer

Attention is then shifted to the Harwell Dekatron, the world’s oldest original working digital computer, built in the early 1950s at the UK’s Atomic Energy Research Establishment in Harwell. Also known as the 'WITCH' (Wolverhampton Instrument for Teaching Computation), it was used for mathematical calculations and prioritized reliability over speed. Although not faster than a human mathematician, the machine could work tirelessly. Its restoration was completed in 2012, making it a significant piece of computing history, reflecting the origins of automation.

🏗️ EDSAC: Rebuilding a Giant from 1949

The video then discusses the ongoing reconstruction of EDSAC (Electronic Delay Storage Automatic Calculator), which is expected to be completed in 2018. EDSAC, originally built in 1949, is one of the first computers built for general use, with a vast valve-based architecture. Its significance lies in being the first computer available for use by scientists and engineers who didn’t build it. It played a pivotal role in early scientific computing, even contributing to Nobel Prize-winning research. The new replica will weigh around 2 tons and house approximately 1,000 words of memory.

🏢 ICL 2966: A Massive 1980s Mainframe

The ICL 2966 Mainframe, one of the largest systems in the museum, is showcased next. Built in the 1980s by International Computers Limited (ICL), this British computing company was significant in its era. The system includes 33 cabinets, 5 for the processor and 20 for hard drives, offering storage ranging from 80MB to 200MB. This machine was used by the Tarmac Construction Company until it was decommissioned in 1999 due to concerns over the Y2K bug. The sheer size and complexity of this system serve as a reminder of the monumental scale of early computers.

📺 Reflecting on the Early Era of Computing

The final segment emphasizes the museum's importance in preserving the history of computing. It showcases early machines like Colossus, EDSAC, and the WITCH, alongside the ICL 2966 Mainframe. The video concludes by mentioning that the museum also houses other exhibits, such as early PCs, thermionic valves, and large hard disk platters. The narrator hints at covering these fascinating items in a future video and encourages viewers to subscribe for more insights into the development of early computers.

Keywords

💡Colossus

Colossus was the world's first electronic computer, developed during World War II at Bletchley Park in the United Kingdom. Designed by Tommy Flowers, it was used specifically for code-breaking, helping to decipher encrypted German communications. The Colossus Mark 1 entered service in 1944, with a total of 10 machines being used by the war's end. Despite being programmable, it was not a general-purpose computer and operated by manually setting switches and plugs to select algorithms.

💡Bletchley Park

Bletchley Park was a top-secret British facility during World War II, known for its role in code-breaking efforts, particularly against German military communications. It is the site where the Colossus computer was developed and used. The park played a crucial role in the Allied victory, showcasing the early use of computing technology in intelligence and warfare.

💡Harwell Dekatron

The Harwell Dekatron, also known as the 'WITCH,' is the world’s oldest original working digital computer. It was built in the 1950s at the Atomic Energy Research Establishment in Harwell and used for automating mathematical calculations. Unlike modern computers, it prioritized reliability and simplicity over speed. The machine ran continuously for long periods and was later used as an educational tool before being restored in 2012.

💡EDSAC

The Electronic Delay Storage Automatic Calculator (EDSAC) was one of the first computers designed for general use by people who did not build it. Developed at Cambridge University and first operational in 1949, EDSAC played a significant role in scientific research, assisting in work that led to three Nobel Prizes. It is notable for its impact on the development of user-oriented computing, making complex calculations accessible to non-specialists.

💡Vacuum Tube Technology

Vacuum tubes, also known as thermionic valves, were used in early computers like Colossus and EDSAC. These components controlled the flow of electricity in the circuits, allowing the machines to perform calculations. However, they were delicate and prone to failure, which required the computers to remain powered on continuously. Vacuum tubes were a key step in the evolution of electronic computing before being replaced by transistors.

💡Code-breaking

Code-breaking refers to the process of decrypting secret communications, a critical function performed at Bletchley Park during World War II. The Colossus computer was specifically developed to break the codes used by the German military’s Lorenz encryption machine, allowing Allied forces to intercept and understand enemy messages. This work significantly contributed to the war effort and demonstrated the potential of early computing technology in intelligence.

💡ICL 2966 Mainframe

The ICL 2966 Mainframe is a large-scale computer system developed by International Computers Limited in the 1980s. This massive machine, displayed at the National Museum of Computing, was used by businesses like the Tarmac Construction Company until the late 1990s. It highlights the evolution of computing technology from specialized war machines to general-purpose commercial and industrial applications.

💡Punch Tape

Punch tape was a form of data storage used in early computers like Colossus, where information was encoded on paper tape with holes punched in specific patterns. The tape would loop continuously through the machine, allowing it to read data and perform operations. This primitive form of memory was a crucial component of early programmable computers before the advent of electronic storage.

💡National Museum of Computing

The National Museum of Computing, located at Bletchley Park, preserves and exhibits historic computers, including reconstructions of Colossus and other pioneering machines. The museum showcases the evolution of computing technology from its earliest days to modern times, providing a unique insight into the development and impact of digital technology on society.

💡Artificial Intelligence

Artificial Intelligence (AI) refers to the simulation of human intelligence by machines. The video highlights the early origins of mental automation with computers like the Harwell Dekatron, which could perform mathematical tasks continuously without fatigue. This historical context underscores the progression towards today’s AI, where machines perform complex tasks across various industries.

Highlights

Introduction to the National Museum of Computing at Bletchley Park, UK.

Colossus, the world's first electronic computer, designed by Tommy Flowers.

Colossus Mark 1 entered service in February 1944, with Mark 2 following in June 1944.

Ten Colossus computers were used by code breakers at Bletchley Park by the end of WWII.

Colossus was specifically designed to decipher encrypted German High Command messages.

Colossus utilized vacuum tube technology with Mark 1 having 1,600 tubes and Mark 2 around 22,000.

Colossus had no RAM, relying on a continuous loop of punched paper tape for data input.

Colossus could process up to 5,000 characters per second.

Programming Colossus involved manual setting of switches and plugs, without an operating system.

Final output from Colossus was directed to an electric typewriter.

The Harwell Dekatron, the world's oldest original working digital computer, is featured.

The Harwell Dekatron used 828 Dekatron counting tubes for program and data storage.

The machine was designed for simplicity, reliability, and attended operation.

The Harwell Dekatron was used for automating mathematical work and was operational until 1973.

The EDSAC, an electronic delay storage automatic calculator, is being rebuilt at the museum.

The original EDSAC was designed in 1947 and was operational until 1958.

The ICL 2966 Mainframe, constructed between 1985 and 1987, is showcased.

The ICL 2966 was used by the Tarmac Construction Company until decommissioned due to Y2K concerns.

The National Museum of Computing provides a reminder of the early days of computing.

The museum also features early PCs, thermionic valves, and large hard disk platters.

Transcripts

[Music]

welcome to another video from explaining

computers.com this time we're going to

look at some amazing historic computers

at the national museum of

computing this is located at Bletchley

Park in United Kingdom which during

World War II was a top secret Co

breaking

[Applause]

facility here we have Colossus the

world's first electronic

computer the machine was designed and

built by a man called Tommy flowers with

a prototype Marked One Colossus entering

service in February

1944 a mark 2 Colossus was then

developed with the first of these put

into operation in June 1944

in total by the end of the war 10

Colossus computers were being used by

the code Breakers at Bletchley

[Applause]

Park while Colossus is programmable it's

not a general purpose computer rather it

was developed solely to help decipher

encrypted German High command

messages specifically Colossus was used

to determine the settings of the Len

encryption machine that the Germans use

to scramble each secret communication

as you can see Colossus is based on

vacuum tube or thermic valve technology

with a Mark 1 machine having about 1,600

vacuum tubes and the mark 2 about

22,000 to prevent these notoriously

delicate components from blowing it's

important that they're never turned

off Colossus has no Ram or other form of

electronic or magnetic memory instead

it's fed from a continuous loop of

punched paper tape that circulates

around this bedstead at the end of the

machine a paper tape can contain up to

25,000 5bit characters and travels at up

to 27

mph amazingly the whole thing holds

together and allows Colossus to process

up to 5,000 characters a

second Colossus is programmed by

manually setting the positions of the

rows of switches and plugs that we see

on several of its panels so unlike a

modern computer Colossus has no

operating system and cannot run

highlevel programming languages because

it's not a general purpose computer

Colossus also only runs the specific

application for which it was built with

its switches and plugs being used to

select desired algorithms and other

programmable

parameters while Colossus has lights to

indicate operation it does not have a

monitor star display rather final output

is directed to this electric

typewriter the specific Hardware we're

looking at here is a rebuild of a

Colossus Mark I constructed by a team

led by Tony sail between 1994 and

2017 this fully working computer now

stands in exactly the same location in

Bletchley Park as the original Colossus

9 it really is an amazing machine to

behold and a recreation that makes you

appreciate the extra ordinary

achievements of computing's early

Pioneers the noise it makes is also

hypnotic and you can almost feel the

mechanical pulse of Colossus resonating

out from the past and deep into our

Computing

[Applause]

future while the coloss computer we were

just looking at is a reconstruction here

we have the world's oldest original

working digital

computer when it was first built it was

known as the Harwell decatron as it was

made at the atomic energy research

establishment in Harwell and used 828

decatron counting tubes for program and

data

storage this enormous machine was built

to automate tus mathematical work its

design also prioritized Simplicity

reliability and attended operation over

pure computational speed in practice

this resulted in a computer that's not

much faster than a skilled mathematician

and Performing calculations but which

does not get tired and which can work

relentlessly for long periods as we look

ahead to the 2020s and the mass

automation of many jobs by artificial

intelligence it's interesting to reflect

that this is where the trend for mental

automation

started the Harwell decatron first ran

in 1951 enter service in 1952 and was

used in Harwell until

1957 it was then offered as a prize in a

competition and won by an educational

establishment in wolver

Hampton here it became known as the

witch or wolver Hampton instrument for

teaching computation from Harwell and

remained in use until

1973 having been disassembled and kept

in storage in 2009 the machine was

delivered to the national museum of

computing for restoration where it was

first re booted in November

2012 to add to their collection the

national museum of computing is

rebuilding a working replica of the

edsac or electronic delay storage

automatic

calculator this is due to be completed

in Spring 2018 but is already very large

and very impressive as somebody working

on the project told me this is a

computer where you can walk inside the

CPU the final reconstructed edsac will

have about 140 shelves of valve based

Electronics supported across 12 racks

and will weigh about 2 tons with about

1,000 words or roughly 3 kiloby of

memory the machine will be able to

process about 650 instructions a

second the original edsac was designed

in 1947 and run its first program in May

1949 at its home in the Cambridge

University mathematical laboratory the

machine is important because it was the

first computer constructed for General

use by people who had not built it edsac

remained in operation until July 1958

and across its 9 years of service proved

invaluable to many Cambridge scientists

and Engineers three of these even won a

Nobel Prize for work that depended on

EXA calculations

bringing us closer to the present day

this is an ICL 2966 Mainframe and so is

this and so is this this quite enormous

machine fills a significant proportion

of the Museum's large systems gallery

and was constructed somewhere between

1985 and

1987 its manufacturer was ICL or

International computers limited which

between 1968 and 2002 was a very large

British Computing company

of the 33 cabinets on display five house

the processor while 20 are exchangeable

hard drives that provide the machine

with its storage the plastic containers

you can see on top of several units are

used to hold discs removed from the

drives the large containers house

platters providing 200 megab of storage

while the smaller ones contain 80

megab the ICL 2966 machine was used by

the tarmac Construction Company until

1999 when it was finally decommissioned

because it was expected to fail as a

result of the Y2K problem or millennium

bug for anybody with an interesting

Computing the national museum of

computing is an amazing place to visit

in the modern world it's far too easy to

forget how different early computers

were from the computers we enjoy today

and this place provides a powerful

reminder are the very beginnings of

computing now in addition to other large

systems we see here things like the

Colossus and the edsac and the witch and

this extraordinar large ICL Mainframe

the Museum's also got lots of other

exhibits it's got these amazing

thermionic valves it's got these

extraordinary large hard dis platters

that you probably spotted earlier and

it's also got lots of early PCS so in

fact I'm going to cover them separately

in another

video but now that's it for this time

time if you've enjoyed this video please

press that like button if you haven't

subscribed Please Subscribe and I hope

to talk to you again very soon

[Music]