On Wed 03 Jun, Richard Earnshaw wrote:
> 
> The APCS is documented in the ARM SDT reference guide, but I'm afraid that 
> is only available with the ARM toolkit (I'm not aware of this document 
> being on the ARM Web server).  Educational establishments can obtain older 
> versions of the SDT (which still contain the documentation in PDF format) 
> via ARM's University Programme; others can try requesting demo versions of 
> the SDT which also contain PDF copies of the documentation.  See the Web 
> pages (www.arm.com) for details of both of these.

The APCS is also documented in the Acorn DDE (C v4) user guide which
can also be found on the Tekkie Disc (CD).

I don't know whether there have been any changes to that after this
was published, but there should be some information there as a
start anyway.

I believe that you can get the Tekkie Disc for around GBP 50
from some suppliers nowadays.

Kjetil B.
mailto:kjetil@thomassen.priv.no
http://home.eunet.no/~kjetilbt/