I have a couple of BBC computers that are not functioning and would like to know if anybody knows or has monitored and recorded how a BBC boots up and checks its hardware? I think I can then put a logic analyser on there and see where it gets stuck. If not I'll have to take a good one and do it myself, just interested if anybodys tried this really?

Martin

Hi Martin,

I recommend you take this question to the StarDot forums, where there are lots of friendly Beeb experts who might be able to give you a hand!

The RetroSoftware forums are more focused on software development than troubleshooting hardware problems.

In case it's of any use to you though, there's an article here which walks you through the reset sequence of OS 1.20, and explains in some reasonable detail what it's doing.

Otherwise, if you just want to dive into the nitty-gritty, there's a commented OS 1.20 disassembly here (the reset routine starts at &D9CD, here).

This would be a suitable thread to read on *.
http://www.stardot.org.uk/forums/viewtopic.php?f=3&t=3348&start=0

Thank you very much That's a great start