A series on members' early computing experiences has been proposed. John was inspired, by a passing reference to punch cards in an exchange on the Bulletin Board, to tell the following tale...
The first computer I had anything to do with was a Ferranti Mercury in the Electrical Engineering Department of Manchester (UK) University. It was as big as a barn. It used mercury sonic delay lines as RAM. Different internal functions had different bit sizes per word, and hence different length tubes of mercury. I think it had 1024 words of RAM all up. There was a magnetic drum - about as big as a Mini, and with a pathetic amount of storage.
It had both fast and slow synchronisation, which were not very good. You had to get the cabinet doors at just the right angle to get the breeze coming in from the corridor, or you lost synch. If that happened it was "all over, Red Rover" until synch was re-established - by which time we could have got through a four course meal, if we had not been impoverished students on grants. Input/output was on paper tape. The teleprinters we used were about 99.9% accurate, which sounds great ... except hat our reels of paper tape were about a foot across, so that correcting a onecharacter error firstly took an age, and secondly could generate three or four more errors. Oh, for the luxury of punch cards!
If you have been exposed to punch cards, you will be familiar with the technique of sticking the cards back in and punching extra holes. Perhaps there were only hand punches available, or perhaps all the powered machines were being hogged, and you did not want to risk further errors which could have come from repunching the whole card. This worked quite well with the thick card used in punch cards, but I have had to attempt the same thing with floppy paper tape.
I sympathised with Mrs Beaton about "first catching one's hare": try finding just which character to change in a paper tape reel a foot in diameter! Just to add piquancy to the whole operation, these paper tape reels were just loose paper; they were not on any metal reel or anything - so guess what used to happen.
Those were the days. And you think that you had problems?
[Paper tape? Paper tape?!? Looxury! When Ah were a lad, we `ad t' tooch wires wi' toongue t' tell one from zero! -Tech Ed]