Vintage tech from 1971
Litton ABS1241/LBS1241 computer
Why the interest in this Litton Business Systems computer? This is the first computer I worked on as a paid "proper" job. My employer was Sweda International, part of Litton Industries (until sold to the Hugin Group PLC in 1985), which is why it had to use this (awful) computer that was made by its parent company. There were three systems running in the one room which kept us warm in the summer; cooling was achieved by opening the windows wide onto a public road.
The ABS1241 (also known as the LBS1241) comprised the main computer model 1230, with the 1231 printer and the 1232 paper tape reader/punch machine that was so slow it could be read faster by a human than by the machine itself.
The three computers were not connected to each other (or anything else). Data entry was via the keyboard and the paper tape reader. Output was via the printer an paper tape punch. There was no internal disk for data storage. The programs were written to paper tape.
It was a 40-bit serial machine with magnetic drum main memory and SSI TTL integrated circuits. The programming language was an interpreted machine language that was very similar to its native machine language.
The paper tape had a habit of tearing, especially when the data reel was about 10 inches in diameter. It was easily repaired with adhesive patches. Data adjustments could be made by slicing out part of the tape and replacing it with the change. There was a handy manual tool for making these adjustments.