Date : Sat, 21 Nov 2009 00:16:25 +0000
From : mlist@... (Steven Flintham)
Subject: Is there a 65Tube-style BBC emulator available
On Fri, 2009-11-20 at 20:35 +0000, Michael Firth wrote:
> Apologies to anyone who downloaded the archive I uploaded earlier, there
> were a couple of problems with it.
[...]
Hi Michael. I did give this a quick go not long after you posted it and
it seemed a bit unreliable, so maybe this was the problem. I put it to
one side meaning to go back to it later so I didn't investigate the
problems in any detail.
> I'll try and rediscover how the code operates enough to fix some more of
> the problems in the next few days.
Obviously, if this has revived your interest in this code, go ahead. But
please don't do it on my account! I think there's potential here for a
65Tube-ish emulator, but just playing around with it earlier made me
realise that such an emulator is not quite as trivial as I'd thought.
I guess I didn't realise how much 65Tube (presumably) benefits from
running on top of RISC OS, which really is quite BBC MOS-like. To take a
trivial example, I wanted to *EXEC my source code into the emulator -
oops, that doesn't work, because it just gets passed through to the
shell. So the OS emulation needs to be clever enough to trap things like
that. Not a massive deal in itself, but annoying.
The other thing that strikes me as a bit tricky is handling Escape. In
65Tube this just works, either because they were clever or because RISC
OS is BBC-like. But in a naive getchar()-style emulator, you have to do
Escape then Return (I think, and I'm not sure that will always behave in
a truly BBC-like way). It doesn't sound much, but I think that could get
annoying pretty fast. I'd also like to handle Escape properly in the BBC
code I'm writing, so I'd like the emulator to be 'realistic' in this
regard.
Maybe I'm exaggerating the difficulties, I have been known to do
that. :-) Just trying to get something running 'natively' does make me
appreciate the rpcemu+65Tube approach a bit more though.
Steve