As much as you may want it to be, this book is not very good.
If you don't want to read it (and I don't blame you), the examples are mostly badly designed programs -- even for BASIC -- with a stream of consciousness describing how to fix them. As you read it, you think, "Uh, maybe the design is no good?" This is never brought up.
One example uses a floating point number X.Y to represent two ASCII characters (!). This is "patched" to deal with two special cases by just hard coding a string in the code. But then it's revealed there are only 15 cases in total. You might as well hard code the strings anyway since the data set is so small, thus avoiding the bizarre numerical representation of characters.
@GeoffWozniak > One example uses a floating point number X.Y to represent two ASCII characters (!).
Cairo's *build system* does this - it picks some specific absurd floating point number carefully constructed to determine endianness of floats.... and it does so by running strings to see how the float got represented
it makes me scratch my head