Ada development with RISC OS


When talking about RISC OS software development, most people immediately think about languages like C, BBC Basic and ARM Assembler. Some even use Sather, Perl or Python. This website however is dedicated to the development of Ada software for RISC OS. No matter if you are a RISC OS expert without any Ada knowledge, or if you are an Ada expert without any RISC OS knowledge - I am sure that you will find some interesting stuff here.

This website will try to be some kind of a repository for all the Ada stuff related to RISC OS. If you have any suggestions on how to improve the site (e.g. by correcting the spelling and grammar mistakes) - please mail me.

Getting started

Basically, all you need is a package consisting of GCC, UnixLib, CLib stub and GNAT 3.03. You can download it here:

Just unzip it anywhere on your system. If you already have GCC 2.7.2 somewhere on your system, please follow the instructions inside the archive on how to merge GNAT with your installation. There are also some simple examples inside this package that teach you how to use the compiler in a RISC OS environment.

To edit Ada source code, even !Edit would suffice. However, you are strongly encouraged to use either Zap or StrongEd for the job. More adventuruous people could try out the port of vim.

To get the optimum out of Zap and StrongEd, have a look at the following modules for a syntax-colouring Ada mode:

Developing 32bit software with GNAT

After the Iyonix PC announcement from Castle Technologies, it should be obvious that 32bit RISC OS is the future for the platform. C/C++ developers can already produce 26/32bit compatible code with the help of Castle's recently released C/C++ development suite. After many hours of work, mainly done by Peter Naulls and Martin Würthner, there is now a first alpha release available of most of the components needed to produce 26/32bit compatible code with GNAT.

The package has not received much testing, and there are known problems with it. Also, you will need Castle's C/C++ development suite because it relies on the "link" linker being available as well as the new 32bit compatible SharedCLibrary stubs. It is hoped that both components can be replaced in the future by "free" equivalents.

In the meantime, you can download the first alpha version of the 32bit GNAT compatibility package. Please read the accompanying !ReadMe file before doing anything.

Need to know more? Like to discuss Ada stuff with fellow RISC OS developers?

comp.sys.acorn.programmer is probably not the best place to discuss Ada specific stuff - nearly all of the readers are mainly interested in developing in BBC Basic, C or ARM Assembler.

Because of this, a mailing list has been launched for discussion about RISC OS related Ada stuff.

Yahoo! Groups Logo
Click to subscribe to riscos-ada

If you have RISC OS and non-Ada specific questions, a newsgroup posting is the recommended way to get help however.

Ada and the RISC OS Graphical User Interface

Ada itself does not contain any packages to create a graphical user interface (in contrast to e.g. Java). Therefore, a package for WIMP programming must be specifically developed for true RISC OS software development.

Quite a long time ago, when I decided to write CDBurn in Ada, I wrote a simple, procedural, low-level WIMP binding nearly on SWI level. You can have a look here. After having to maintain CDBurn (and the binding) for nearly 5 years now, I can safely say that the binding is not really ideally suited to WIMP development.

The plan for a new, shiny, object-oriented WIMP library is quite old now - we have some sketchy ideas and a cunning name ("Rascal") along with a SourceForge-like repository (

How to learn Ada

Fortunately, there are some very interesting online resources available that you can use to learn everything about Ada (and even programming with Ada ;-)).


Online tutorials


Links, links, links

The following list is a collection of my favourite Ada links. All of them deal with plain Ada in a system independant sense, so you won't find any mention of RISC OS anywhere - mostly because the only dedicated RISC OS-Ada-site is the one you are just reading ;-)

The "first stop" website for every Ada developer is AdaPower by David Botton. There are many Ada sources, tutorials, tips and general articles to be found there.

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