Date   : Sat, 21 Nov 2009 23:20:56 +0100
From   : rick@... (Rick Murray)
Subject: Is there a 65Tube-style BBC emulator available for

Steven Flintham wrote:

> I could, but I like the safety net of being able to kill the taskwindow
> if my program crashes and locks up the emulated BBC. Or am I overlooking
> something there?

Actually, I don't remember how I handled this, though I usually used a 
module that provided the hotkey ^Esc as a safety-net option to forcibly 
kill an errant task (I think it stuffed in a call to OS_Exit?).


> Admittedly rebooting the emulated RPC is not a major chore,

...but do it enough and it will become one. I understand that.


> it looks as though such an emulator is just that bit more work than
 > I thought.

Indeed it is, though things are marginally simpler with 65Tube as you 
don't need to take a lot of time worrying about accurate hardware 
emulations. I think most of what 65Tube can do is done simply by passing 
it all to the "host", I don't believe it can even draw a line natively. 
:-) Somewhat different to a BBC emulator like BeebEm, !65Host, etc...


> Also, although I'm using a desktop PC right now, I can envision wanting
> to work on this pet project on my netbook and I suspect that rpcemu is
> not going to be very battery-friendly, since it's just sat at 100% CPU
> all the time.

Of course, as there is LOADS of stuff going on. All the beckground 
interrupts, VSyncs and clock ticks and what-have-you plus the memory 
subsystem and the screen refresh and shall I go on? When a RiscPC is 
running, everything is operating in parallel to provide the Acorn 
experience. Apart from a rather crap screenblanker, there's nothing in 
the way of a "sleep" mode for a RiscPC (it's not as if a machine like 
that really needs one!) hence it is continually active.
So is your emulator.
Thus, it will max out its available CPU timeslice and never let up. In 
this respect, a native tube emulator might be better, but on the other 
hand won't that also sit in a loop awaiting something to happen? It 
can't exactly stop on inactivity or else if it is running a program 
(i.e. BASIC or something) then that would grind to a halt...?


Best wishes,

Rick.

-- 
Rick Murray, eeePC901 & ADSL WiFI'd into it, all ETLAs!
BBC B: DNFS, 2 x 5.25" floppies, EPROM prog, Acorn TTX
E01S FileStore, A3000/A5000/RiscPC/various PCs/blahblah...
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