iPad Screenshots


Go back in time and learn to program Forth with this Jupiter ACE on your iPad.

The Jupiter ACE was a home computer released back in 1982. While all other home computers at the time used BASIC as the built in programming language, the Jupiter ACE used Forth.

This emulator is built with freely available documents and source code. Project files are available on github.

The Jupiter ACE brand has been revived here https://jupiter-ace.com, stay tuned.

Jupiter ACE is trademark of Andrews UK Ltd.

What's New

Version 1.2

- Update for iOS 9 and later
- Fix some [Enter] buttons

Ratings and Reviews

3.9 out of 5
7 Ratings
7 Ratings
Universe Observer

A little better with each revision

9 Apr 2018

I could not continue my chain of reviews ... it always happens with updates. Edward Patel is back and working through some of the “annoying” issues with his Jupiter Ace emulator on iOS, in particular with the app on iPad Pro 12.9 in. devices.

Results now show up on scrolled down screen. Manipulation of screen and keyboard still remains very awkward. It would be better to just have a static screen of the entire surface of the Jupiter Ace and to use the traditional gear type icon for settings and question mark icon for the help section (which is really good).

The second thing which either needs to be dumped altogether or made a user option to disable is the key repeat. It is just too “sensitive” and becomes very annoying very quickly.

There were obvious user interface annoyances on the Jupiter Ace; but, the app should attempt to clean up those problems. While I laud the effort to bring back a piece of history and nostalgia, I echo what some user’s have said, there needs to be a good Forth interpreter written for iOS that adheres to the language standard and does not emulate past devices.

I still want to love this app and will continue to monitor and test improvements though ... so keep the improvements coming.

Developer Response

Sorry you had some problems. It was already 3 years old when you tested it. Try now, I just updated it this weekend. Have fun! Cheers.

Also, looks like I should mention how to drag the screen down. Please see this https://youtu.be/-2LUG2X1nSg where I show how it works from a cold install. Cheers.


No native Forth so far.

That's the only Forth for iOS.


A good forth for the iPad

It is good that there is a good forth for the iPad.


Edward Patel
7.4 MB
Requires iOS 9.0 or later. Compatible with iPad.
Age Rating
Rated 4+
© 2018 Memention AB


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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