I have some BASIC programmes I wrote many years ago on my A5000 under RISC OS 3.00. They don't run very well (or at all, in some cases) on an emulator with RISC OS 3.11. Were there changes in the BASIC interpreter between 3.00 and 3.11, or do I need to do something differently?
So it seems that there was a BBC Basic v1.02 on machines < RO 3.11 and v1.05 at RO 3.11. Maybe this helps a little bit.
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Just for my own interest: What kind of machine was it with RISC OS 3.0?