It also has the sort of low-level detail that childrens' books on computers would not contain in later decades; I can't imagine a recent children's book on computers (or, indeed, anything before a second-year university subject) going into error-correcting codes, opcodes or the magnetic encoding of binary data. Mind you, back then computers were simpler; the physical details of how data is stored wasn't hidden behind a high-level interface like ATAPI or USB Mass Storage and machine language wasn't an esoteric specialty confined to compiler writers, BIOS hackers and hardcore masochists. These days, being interested in things that are too low-level is at best quaint, and at worst casts suspicion on one as being a potential h4x0r/virus writer/DRM cracker/troublemaker; all the details of computers one is meant to know about are exposed at a higher, and much more user-friendly, level, so why would anyone delve deeper if they're not either one of a tiny number of specialists or up to no good?
Actually I might still have the project. I'll have to see whether I can find it when I go back there on Saturday...
When I was 10 I got to write a project on computers for school (we had to do a 20 something page workbook on a topic that interested us - I seem to remember most of the girls did horses, or something of that ilk). I remember I included stuff like punch cards, magnetic tape and processor chips and finding all that stuff very exciting. I also wrote a program in Basic about how to calculate how many tiles you would need for a roof, and how much they would cost you. Most children have houses with books on cookery and cars lying about the place. I had books on programming language.
My enthusiasm resulted in me learning Basic as extra work the rest of the year.
Fun times...