A programming language in the genre of pedagogical language by Chris Pressey, Cat's Eye Technologies, ca 1993

Esowiki: Maentwrog

Maentwrog is an RPN-calculator-turned-FORTH-interpreter which probably counts as Chris Pressey's first proper programming language. It was implemented on his Amiga 500 in 1993, then lost and unearthed multiple times. It is hardly remarkable, save that it spawned Befunge-93.

Sample Program

*a *b *c
0 =a 1 =b
: fib a b + =c c . b =a c =b c 100000 < @fib ;
1 . fib

Computational Class

known not Turing-complete

Programming Paradigms

Defined by

maentw.c in the Maentwrog distribution




There are no extant example programs from the time the language was first implemented — I tried writing the Sieve of Eratosthenes in it once, but never got it to work, probably because == was not implemented correctly. Recently, example programs and a description of the language (which has become the provisional spec) have been provided by Marinus — thanks Marinus!

Also included in the Maentwrog distribution, just for fun, are some other contemporaneous C programs of mine: an RPN calculator which was the predecessor of Maentwrog, a simple recursive-descent expression parser, and a simple cellular automata parser (a distant ancestor of ALPACA, perhaps?)

Maentwrog is the name of a town in Wales, but the usage of its name for this language came via Douglas Adams' "The Meaning of Liff", wherein it is defined thusly: "MAENTWROG (n. Welsh) Celtic word for a computer spelling mistake."