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JBit is small java application for mobile phones (MIDlet) that gives you a programmable 8-bit microcomputer. With JBit, you can edit, save, run and debug assembly (6502) programs directly on your phone.

debugging / maze

WAP Site
Limited, low-bandwidth web site in WML.
Browse a gallery of some programs made with JBit.
Install JBit on your phone or download its source code.
Learn how to program and customize JBit.
Tips on how to install the jbit binary (and cc65) in a terminal.
For modern browsers (IE8+).
Additional modules and tools.


11 Jun 2017 - jbit 2.1.1 is available. io2sim: Palette and console. Added device id in .jb header.

23 Apr 2017 - jbit 2.1.0 is available. io2sim: libretro core and win32 IO2 simulator (MicroIO only for now). ZOOM2 flag.

14 Apr 2017 - jbit 2.0.3 is available. The new GAMESET request replaces the old template.jb / JBitGameKit.

20 Feb 2016 - jbit 2.0.2 is available. Basic TTY support in xv65. MicroIO ported to MS-DOS.

31 Jan 2016 - jbit 2.0.1 is available. Record Store API. Android binaries (for terminals, no app). Removed js version.

13 Jan 2014 - jbit 2.0.0 is available. Merged the J2ME, native and javascript repositories.

4 Oct 2013 - jbit 1.2 native/webapp is available. C++/JavaScript version of JBit for PCs and modern browsers (IE8+).

29 Aug 2013 - JBDoc-20130829 is available. Added: IO Programming (1) - Requests, Images and Sprites.

19 Aug 2012 - JBDoc-20120819 is available. Smaller font added. gameapi (slightly) extended. epub and mobi formats added.

2 Apr 2012 - JBDoc-1.0.0 is available. First MIDP version.

19 Jun 2011 - JBit-20110619 is available. Just a quickfix: solved a problem with confirmation dialogs on Samsung phones.

5 Jun 2011 - JBit-20110605 is available. The monitor now supports breakpoint and step out, and the IO chip now provides tone generation and vibra.

29 Jun 2010 - JBit-20100629 is available. It includes basic support for touch-screen phones.

25 May 2010 - JBit-20100525 is available. The Paint module now supports editing multi-color images.