I am going to talk about computers. This may seem strange after  One, Two, Three, which showed some of our primitive calculating methods back in the fifties. Computers had originated in the Second World War but even by the 60s had not developed beyond specialist scientific ones used in universities and government organizations. No computer then was as powerful as the microchips in today’s calculators and mobile telephones.
Most of the pictures will come from my visit to Bletchley Park and I will start with three pictures from there to illustrate the earlier blog about calculators. As always, click on a picture to see it enlarged.
I thought my explanation of logarithms might be difficult. It’s all made clear in this display at Bletchley. (Possibly not.)
A larger than life slide-rule.
And a Facit, an early device for multiplication. You can’t see the working – cog wheels inside, operated by turning the handle.
I need to say at this point that from the seventies I worked at GCHQ, where we had more powerful computers than almost anywhere else and knowledge about the history of computers than was then not public. Recently this has changed and it is now known that the history of computers started at Bletchley Park during the war with machines built solely to solely to decode the German ‘Enigma’ machines.
The picture is a very old machine using valves. It could do simple addition and multiplication and not much else.
Back in the fifties there were virtually no computers – just in some universities, some large businesses and some major government departments, such as GCHQ and the Meteorological Office – weather forecasting was not easy. I’m not sure than any establishment actually had two computers!
So we had none of the phenomena associated with automated processing – no telephone banking; no bar-codes, no automatic washing machines, no spreadsheets, no mobile phones, no itemized till receipts, no e-mail, no Power Point presentations, no Internet newsgroups or chat rooms, no credit cards, no tablets or even laptops, no games consoles, …
Paper Tape and Cards
The simplest job on a computer could take hours and was a complex process, starting with the generation of a paper tape or punched cards and ending with a crude printed output. A lot of what follows comes from my experiences with computers, dating from the late sixties.
Punched paper tape, shown in the picture above, was a continuous stream of paper about an inch wide. Each row of dots across the paper represented a single character – a letter, number, special character or space – and the tape would have been produced in something a bit like a typewriter. The picture above shows a paper-tape reader made by International Computers Limited (ICL) – a UK company, now part of Fujitsu.
Creating and reading paper-tape were both quite slow processes and paper could be torn with unfortunate results. If you ran a test program with paper-tape there were almost always mistakes – so it had to be corrected. The only way you can correct a paper tape is to create a copy! For a minor change, such as adding a comma (a very common correction) you might get away with a fairly straightforward copy with editing but for much more you could end up just rewriting it!
In some ways, punched cards were similar. Each column of holes represents a single character so each card is an 80 character line of code or data. The card below has the single FORTAN statement:
Z(1) + Y + W(1)
With PROJ1039 as a program name in the field at the end.
[I won’t go into details but oldies will remember FORTRAN (from FORMula TRANslation) as a programming language for mathematical and scientific work. At the time, perhaps, COBOL (Common Business Oriented Language) was more common. Others such as BASIC (Beginners All-purpose Symbolic Instruction Code) came later.]
Cards were easier because you might need to just change one card rather than rewrite the whole tape.
Above is an early hand operated machine to make punched cards. Pressing an appropriate selection of tabs simultaneously would create a single character and advance to the next. (You had to know which holes represented which letters!) You can see it was difficult, long-winded and liable to mistakes – one mistake and you would have to start again. I did see machines like this in the early seventies but by then we had progressed to what is shown in the next picture:
These were more like electric typewriters. You used the keys like a typewriter and cards were punched and stacked. A typical program might take 500 to 1000 cards, generally stored in open metal boxes that held 2000 cards.
Computers in the 60s and 70s
I have several memories of computers in the late sixties, starting with half a year working at the Ford Motor Company tractor factory at Basildon. As you have read in  One, Two, Three. Ford was a large multi-national company. I think it had one computer, which tried to handle finances, tracking production and parts and other things. It did this, more or less, by running a series of programs once a day. In the morning we would have new printouts – large stacks of paper showing what was where. Whatever we did, there would be no update until the next day.
In another temporary job later at Dollis Hill (The Post Office Research Centre, later relocated to Martlesham, now Adastral Park) I used an ICL machine driven by paper tape. After weeks of preparation and producing paper tape, it was a case of booking the computer, large enough to fill a large room, for an hour for its sole use.
This is part of a more modern computer, from the early seventies. You can see a magnetic tape, which was the main way of storing data – the only way to hold large amounts of permanent data. They were 2400 feet long and if you wanted the last line you had to read all the way through – and rewind back to the start before unloading!
Above is a hard disk array, called a 2314, heavy and something like two feet wide. When installed, they span at high speed and it was possible to read any location almost immediately. The SD card that you might put in a camera today holds maybe a hundred times as much data as this, is more reliable and is much faster!
Here is a line printer. It prints mechanically, line by line and would have produced hundreds of thousands of pages every day – the only form of output. Its output was the familiar fanfold sheets, stacked into piles. Simple monochrome text was the only option.
Because they were mechanical and relatively fast they were very noisy. That’s why the mechanism is enclosed in the box you can see. (It was well before the full colour inkjet printers we have now)
Apollo Moon Landings
After the War, the USA and USSR were political rivals (as you know from Blog ) and they were very competitive in technological developments. After early Soviet success in space exploration, on 25 May 1961, President John Kennedy pledged the US to putting a man on the Moon by the end of the decade. With a lot of money moved to NASA, the Apollo program just managed this.
On 20 July 1969, Apollo 11 landed on the Moon. Neil Armstrong and Buzz Aldrin walked on the Moon and were brought safely home. (Don’t believe conspiracy theories that say otherwise.) There were very fuzzy black and white television pictures.
The next day I started work at a site where we had among the most powerful computers in the World – still as described above using punched cards and printers as the almost the only input and output devices. I am told that computers are NASA were similar to the one we had at GCHQ. But where we managed with one they had five – four ran in parallel and the fifth checked the other four to get sufficiently reliable results.
The picture above from the ill-fated Apollo 13 Mission may look more modern but the equipment shown is not computer equipment. There are displays from technical measuring equipment, possible inked to computers. It was an impressive achievement without the aid of modern equipment.
The ability to access computers remotely started in the late 70s. WE had a thing called Remote Job Entry (RJE) using teletypes like the next picture.
A teletype is like a typewriter but every character is transmitted down a wire to the main computer, perhaps in another building. The computer had the ability to respond and send characters back. They were still very slow, just simple text. (Final Score on BBC television on Saturday afternoon, shows goals and final football results coming in. Some readers will remember vide-printers and, before those, a teletype. We literally waited and watched while clubs round the country sent in their results in a way that was a little bit faster than making telephone calls – via landlines, not mobile phones!)
With RJE it was also possible to send punched card data up to the main computer. The picture above has, at the left, a facility for pinched paper tape.
The next development was Conversational Remote Batch Entry (CRBE). Instead of a teletype we had a Visual Display Unit (VDU) but it was hardly a significant improvement. The display was still a line by line text machine with green text.
Almost everything to do with modern computers – and modern technology in general – is much more modern.
The trend towards personal computers and home computers dates from the 80s. First PCs used text input and output only, with graphical output. Windows did not come until the late 80s. Even in the early 90s, PCs had disk space of less than a megabyte and memory size considerable less – they were less powerful than current printers (or mobile telephones).
Home computers used to be large boxes – maybe 50 by 50 cm with separate keyboards and displays. Then came laptops, notebooks and tablets.