I wrote a series in Archive magazine on the subject of interfacing to the podule bus in RISC OS computers, which can be found in December 2002 (vol16.3) to September 2003 (16.12), April 2004 (17.7) and June 2004 (17.9). I haven't got around to putting the text online (mail me if you're interested and I'll send the source files) but this page contains extra material referred to in the articles.
Podule specification, current version: PDF, Postscript, Sparkived Drawfiles.
Version 1 of podule specification (plus diagrams in Draw format). Not to be used for new designs, but contains a longer podule ID list.
NetBSD podule ID list (click on the highest version number to see it).
Article 3 chunk directory programs
SVCUtils module for getting at hardware from user mode (BASIC, C, etc).
HAL26 module for hardware abstraction on RISC OS 3.1 to 4.xx machines.
Page by Theo Markettos (email at theo [at@] markettos.org.uk), last modified 2009-07-19
Return to Theo's RISC OS pages.