Rationale [rash-a-nahl] noun reason for an action or decision

Sometimes I get asked why I created the ARM programming area on my website.

The reason is quite simple. I was interested. And looking around, I found little in the way of documentation. There was the very useful ARM instructions document, the sources to an ARM emulator, help files with assemblers, a fair amount of source code, and only one site that provided an introduction but not lots of detail and examples.

So I rolled my own.

I hope you find it useful.

The following is the text that used to be at the top of the index menu...

This originally began as a series of articles on assembler programming in Frobnicate.
It was originally targeted towards the older processors (ARM 2, ARM 250, and ARM 3), but is being updated for newer-generation processors.
The code presented should work on later processors, including the StrongARM. However it has only been tested on ARM 2, ARM 3 and ARM 710.
 
In order to learn assembler, you will need NOTHING more than the desire to learn, and a little free time. Let me repeat that again. You will NOT need a two-hundred pound compiler, sixty megabytes of memory, a two Gb harddisc, and a processor so fast it interferes with your satellite receiver.
If you have an Acorn Archimedes computer, right from an old A305 running some version of Arthur to the very latest machine - you have what you need. And that very important thing is BBC BASIC. Because within BBC BASIC is a powerful compiler. More powerful, some might say, than the professional compilers such as objasm. Is it any wonder some incredible things are written with the BASIC compiler? Such as StrongEd?
Of course, a Desktop and a text editor that understands BASIC files will make your life much easier, so I recommend RISC OS 3. But, if you are happy with Arthur and ARMBE - don't let me interfere with your fun!
 
Please note, however, that the APCS examples require an assembler and a linker (and, possibly, a C compiler). However, it is expected that if you are interested in APCS, you will have one or more of these to hand. And if you don't fancy paying for Acorn's suite or something like EasyC, you can download various bits and pieces (gcc, DrLink, ASM) and make your own suite!