Hi,
The RKRM's can't be compared to javadoc, they're more like "The Java Tutorial".
RKRM's 3. edition consits of:
Amiga ROM Kernel Reference Manual: Libraries
Amiga ROM Kernel Reference Manual: Devices
Amiga ROM Kernel Reference Manual: Includes and Autodocs
Amiga Hardware Reference Manual (not really a part of this series, but a good way to learn about the Amiga hardware)
The last edition of the RKRM is the third. The RKRM's are not free. Currently they are available in html/amigauide on the Amiga Developer CD V2.1 which you still can buy. The paperback version is my preferred version of the RKRM's. The last edition of the RKRM's was released in 1991-1992 and covers the AmigaOS release 2.
The Amiga Developer CD V2.1 can be bought from
schatztruhe.de. This is a must have for any learning AmigaOS developer.
About GCC. On
i n n o i d e a you can download a complete development kit (UAE hardfile or a tgz-archive for real Amiga) consisting of GCC v2.95.3, make, ... . I haven't tried it out my self, I built up my own from
geekgadgets, but I belive it's good. Then you can play around with OS 3 a bit before OS4 arrives.
You asked about changes for programming OS4. Vel, OS4 isn't out yet. And I'm going to wait to learn to program for it until it arrives.
You asked about tutorial web sites for Amiga programming. I can recommend this mailing list for you:
amiga-c. You need to register to use it. Else, you should look around in the amiga.org AmigaOS Developer forum archive. Many people have asked this kind of questions...