Forth V1.4

History:

In the middle of the Eighties of the 20th century there were no affordable Forth computers for me. But I wanted to try this cool programming language urgently! So I had to write an interpreter myself... After an initial version on the Speccy I ported it to the ZX81.

Download:

forth_14.zip Archive with programs for ZX81, ZX Spectrum, and source, 7KB.

Screen snapshots:

Description:

Even thought it served its purpose, it has some errors. You are welcome to correct and to enhance it! Recognized words are:

:

defines a new word, no ";"

constant

defines a new constant

variable

defines a new variable

vlist

lists all words

forget

clears all new words

dup

duplicates the top of the stack

drop

removes the top of the stack

swap

exchanges the two numbers on top of the stack

over

duplicates the second number on top of the stack

rot

rotates the topmost three on the stack

c@

fetches a byte

@

fetches a number

!

stores a number

.

prints a number

if, else, then

conditionals

do, i, loop

loops

mod, /, *

modulus, division, multiplication

+, -

addition, subtraction

<, >, =

comparison

There is room for 15 new words, each of a maximum of 15 words in them.

Who to blame:

Back to my home page.

Comments and such stuff go to: [email protected]