Is there a guide to making sure a program does work across all machines (at least anything reasonably new)? I think I've seen such things in the past, but dealing with specific points, such as 26 v 32 bit. What I really need is to actually get around to writing something - ever since I had an A310 I've been meaning to learn to write nice proper RISC OS applications, and have never got around to learning how (despite churning out plenty of mostly useless little bits and pieces in BASIC, and later C). With a book on the subject now downloadable I've even less excuse, other than the usual one of not wanting to do anything serious on a computer after being sat at one all day at work. It'll require self-discipline (in other words, I'm stuffed).