In my last post I talked about investigating AROS, the modern, open source[*] implementation of the Amiga Operating System. Today I’ve spent some more time on that study, and found some things:
- my strategy last time was to read the AROS application developer guide in order, up to the part about Intuition (the UI toolkit). This taught me about Windows and Gadgets, and the message-passing event system IDCMP. However, one of the first things I discovered today on digging more into that is that people don’t use these things directly.
- The AmigaOS Documentation eschews gadtools (the library for working with Intuition gadgets) in favour of BOOPSI, the Basic Object-Oriented Programming System for Intuition. Its documentation uses demos that only work on the latest (proprietary) AmigaOS, and not on earlier AmigaOS or AROS.
- The AROS documentation eventually led me to discover that even gadgets in BOOPSI are old and busted, and that the Zune[**] widget set for BOOPSI (which is based on the freeware Magic User Interface) is the new hotness.
- This follow-your-nose-and-end-up-lost documentation issue is a big problem. I’ve learned a lot, but mostly follow “this is how this works” with “but you don’t do this”. Plenty of reference is made to the original Amiga developer documentation (which, luckily, I have, on CD in an Amiga-only format) and the MUI docs (which I don’t have but can probably get). This is not an AROS-specific issue, wherever “open source version of X” is documented, the documentation is likely to say “check out the documentation for X”. This only works where the documentation for X is available (imagine, say, if Commodore were to go bust in 1993 and stop publishing their developer docs), and relevant to the reimplementation (imagine, say, if Apple were to change programming language and GNUstep didn’t catch up).
- That AROS is both source and (on m68k, or on UAE) binary compatible with programs that were written in the 1980s is amazing to me, and much more valuable than having latest whizzbang features and smartwatch integration from a modern platform. Leaving aside technical aesthetics which I’m likely to disagree with a lot of people on anyway, AROS and open source[*] systems like it (Haiku, ReactOS, FreeDOS, GNUstep, Lesstif) represent a critical piece of heritage infrastructure.
[*] I’m using this as a shorthand. AROS source code is published under the terms of the AROS Public License, which is not OSI-approved. The source code is available to use, study, share and improve, which many would understand to be “open”.
[**] Unrelated to the Microsoft Zune, and it’s unclear to me which came first.