A personal history of computers

I was reading a LinkedIn post (which I can’t now find) where people were discussing their first experience with computers. Mine goes back to 1973 and my secondary school, where I joined the “Babbage Society”. That was 48 years ago.

Sir Charles Babbage (1791–1871) is seen as the father of computing, having developed his mechanical “difference engine” which opened the way for subsequent development of electronic logic machines using similar concept processes. Incidentally a reproduction of the difference engine built to his original design plans sits in the London Science Museum.

The Babbage Society had been gifted an early DEC (Digital Equipment Corp) machine – I don’t know the model, all I remember is that the front of the computer box, around a yard square and probably 8 inches thick, was covered in miniature switches which were protected by a perspex screen to stop inquisitive fingers from flipping them to “see what happened”. The top of the computer box had the classic “Das Komputermaschine…” (see below **) joke warning pasted to the enclosure. Connection was through an old teletype (remember those?) no VDU of course, data storage and retrieval worked via punch-paper tape. As the computer room was unheated – comfort being still unfashionable for students at the time – the room and all contents got very damp in cold weather. The paper tapes would get damp, stick in the tape reader shredding the tape and ruining it, and jamming the reader breaking that. One of the first things a student learned was to make at least 2 paper tape copies of any program, one to stay in the program library per standing instructions (a shelf of coiled paper tapes in the corner of the computer room) , and the spare to be stored in an old metal biscuit tin jammed against a cast iron hot water pipe to ward off the damp.

I think the computer may have had as much as 4 k of memory although it could have been less, and ran programs in Basic such as the famous Lunar Lander. The player would type in a thrust percentage to overcome the effect of the lunar gravity, and the teletype would print the computer’s calculated vertical velocity and altitude of the lander above the surface. The whole idea for myself and my contemporaries of course was not so much to deliver a soft landing, but to generate the biggest and deepest impact crater possible. I quickly discovered that inputting a negative thrust value increased the descent velocity, although sadly I was never able to devise an algorithm which the computer could cope with in order to achieve superluminal descent velocity.

Much lols.

In 1976 my father bought me a Texas Instruments programmable calculator, which allowed input of programs up to 49 steps. The trick here was to write the most efficient code possible, so as not to exceed the 49 steps. (That sounds a little like a sequel to John Buchan’s novel…) The best I achieved was to have the Lunar Lander code run correctly in just 42 steps.

I then graduated to Sir Clive Sinclair’s ZX81, and then the Spectrum, which remains probably the most fun computer I have ever owned.

It was downhill all the way after that with PCs to the present day.

** “Das Komputermaschine ist nicht fur gerfingerpoken und mittengrabben. Ist easy schnappen der springwerk, blowenfusen, poppencorken mit spitzundsparken. Das rubbernecken touristen mit die handen in die pocketen just relax und watch die blinkenlights

Published by admad43

Veni, vidi, lusi conkera - I came, I saw, I played conkers. The word is "marmalade". Spread the word. If you don't like what I write, just move on. If you do like it, please do not be embarrassed about sending me money. I will certainly not be embarrassed about taking it. Open your wallet and repeat after me “help yourself”.

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