QForth 2.2 is an updated version of Toshiyasu Morita's original. QForth is a small integer Forth for Apple IIe/IIc/IIgs computers. It will not work with an Apple II+. Unlike most Apple Forths, QForth uses normal ProDOS text files for source input. It also has ProDOS file support as well as block disk access. Version 2.2 fixes a couple of small bugs, adds about ten new words to extend the language, and alters the interpreter to suit my tastes.


Source Code Notice#

A note about QForth

The source code for the original Apple IIe version of QForth is given here:

  • QFORTH.S -- main code for the interpreter/compiler
  • QF.REGWRDS1.S -- standard predefined words
  • QF.SPCWRDS1.S -- compiler words
  • QF.FILESYS -- ProDOS file access words

I have no idea as to what Apple II assembler you need to assemble this code yourself, but imagine that it would not be hard to port.


The file QF.FILESYS.S contained an error that prevented using file numbers 1 and 2. The error has been corrected in this copy of the file and in the version running within MacQForth. If you want to work with the original Apple version and cannot re-assemble the file, patch the locations below:


This can be accomplished by using a disk sector editor and careful counting (the original values in these locations are zero). Less daring types can use QForth itself:

162 15481 c!  158 15482 c!

Where's the original?

The original Apple II version of QForth can be found at: as /pub/apple2/8bit/comm/qforth8.shk

You will need ShrinkIt to expand the archive. ShrinkIt is also available on