Date   : Mon, 25 Jul 1994 09:15:50 WET DST
From   : Bonfield James <jkb@...>
Subject: Re: benchmarks

I've been on holiday to the Lake District for the last week. Seems huge
amounts of mail have flown past! 

Chris writes:
>On Sun, 17 Jul 1994, James Fidell wrote:
>> It strikes me that we would probably find a set of benchmarks useful
>> for profiling emulators, for comparing them with each other and for
>> comparing them with the real thing.
>
>I'm not sure that I'm right in this but hang on a tick - aren't you the 
>only one who's got one working James?  ;-)

I think James' is the only working mode 7 system, but I for one (and others
I'm sure) have things working to a level of handling BASIC capably. I (still)
haven't fixed my graphics problems. My emulator now even refuses to display
anything on the Alpha :-(

>On a similar note - how much more than just the 6502 instruction set do I 
>have to emulate to get BBC BASIC running? I'm going to jump for joy when 

Very little I found. In fact I had it running even before I'd finished all the
6502. (Ok, so it got its arithmetic a bit wrong in places ;-)
All I needed to start with were a few quick hooks into the OS. I did this by
(and still do, sorry) an extra 'leap-out-and-hack' opcode ;-) This opcode is
then written in memory to the OS routines so that I can force them to leap to
my own C code.

>I finally see the ">" I've missed for so long but I'd like to have a 
>rough idea of when it's going to happen!

And the beeps too. I've only got one of them so far - the control G. The
second I think is the initialisation of the sound chip.

       James B