Was it already clear for Wozniak in 1975 that Forth looks weird and people won't get it?
> "The key to games was BASIC. Bill Gates was unknown except in the electronics hobby world. Everyone in our club knew that he'd written BASIC for the Intel microprocessor. I sniffed the wind and knew that the key to making my computer good (popular) was to include a high-level language and that it had to be BASIC. Engineers programming in FORTRAN were not going to be what would start a home computer revolution."
I checked the above link to confirm my recollection, but while Forth had been around for a while it wasn't really public until the 70s (versus BASIC). I suspect he wouldn't have even heard of it, or at least not realized its potential, in 1975.
And actually implementing a basic interpreter isn't all that complex. The loop is simple:
Read a line.
If the line starts with an integer, you're adding a line to your program; otherwise you need to interpret then execute.
Read the first word. In some BASICs, this is the first string of characters that matches one of the keywords; in others, it's all the alphanumerics up to a non-alphanumeric.
(In effect) dispatch to the appropriate interpretation routine based on which keyword you just read in. For example, PRINT goes to the argument handler for PRINT, LET goes to the argument handler for LET, and so on.
Then you just have a bunch of routines (read one variable name, read an expression and interpret it as a number, read a destination line number, etc) and different keywords use them in different ways.
It's pretty simple, really. Way easier than writing a full LALR parser.
Since he had an HP calculator, yes