<p>MIX is the world’s first polyunsaturated computer. Like most machines, it has an identifying number - the 1009. This number was found by taking 16 actual computers which are very similar to MIX and on which MIX can be easily simulated, then averaging their numbers with equal weight:</p>
<p>It’s basically machine code.</p>
<p>I have the second edition, from 1973. On the front cover I have my name, address and high-school information so I bought this when I was in high-school which would have been around 1977. The price imprint ($20.25 which was quite a bit for a textbook back then) looks like it came from the Tech Coop (I bought textbooks from the Harvard and Tech Coops back then).</p>
<p>I’d consider COBOL, PASCAL and BASIC higher-level languages and they were by the time of the first edition. Fortran - I’ve always been on the fence with this one - it would probably be considered a 3GL but my guess is that writing a compiler for it would be relatively easier compared to other richer languages.</p>