I'm glad that you brought this up as it reminds me of a lot of stuff about the machine. It's something I learned about the machine when I was a kid and I always took it for granted. Every console I've ever played it on I immediately felt like I had a better knowledge of the thing than the operator. There is probably a number of reasons for that. One of the most important of which is the programming and the way the rotors were made. A lot of the programming was done before the rotors were in place, so the programmer only needed to worry about the configuration of the rotors and not the key schedule. The rotors were made to be partially removable so that the programming could happen faster. Another reason is that the rotors were made to be partially removable so that it could be made to easier to swap the rotors out for maintenance.
The rotors were always reset each day to a different initial position and for different messages. The selector switches allowed the operator to rotate the rotor of the desired 'room' on the keyboard. The paper came with the keys from the same manufacturer, so the way to change a key was to rotate the keyboard with the selector switch, then to press the key on the new position. The rotors were wired in the same way as the machine's rotors and were made to be partially removable for easier maintenance. In fact, the rotors are removable and were not joined in any way mechanically. They are designed to be swapped out without any tools.
Yeah the actual discs themselves seem to hold up well if you take care of them. It's just that I have had many disc drives break on me over the years, even with modern consoles. It's part of the reason why I preferred digital over physical last gen, and why I would just go all digital next gen. Eventually discs are only going to be good for modded consoles or PC emulators.
Sarkar has also written and edited a number of books on English, including a short story called Bibisaree (The Love-chain) in 1962. It is the earliest extant work in English by him. Some of his other books include A Short Study of English Grammar (1951), English Grammar (1959), The English Language in India (1961), Colour My Life (1962), The Book of English Idioms (1969), English Grammar: From the Perspective of Indian Education (1975), The English Language in India (1983), English Grammar: From the Perspective of Indian Education (1989), English Grammar (1990), and The English Language in India (2001). 827ec27edc