Date   : Thu, 11 Aug 2005 19:25:17 +0100
From   : Sprow <info@...>
Subject: Re: 80186 co-pro

In article <1123757037.7436.40.camel@...>,
   Jules Richardson <julesrichardsonuk@...> wrote:

[snip- co pro based on WDC 14MHz 6502]

[snip ARM copro]

> > >  a) emulate the 6502 tube/65C102 turbo as required in software on the
> > >     ARM. 
> > >
> > >  b) use a soft 6502 blatted into the spare space in the programmable 
> > >     logic emulating the Tube IC
> >
> > Hmm... any room in there for a Z80 as well? ;-)

Why both at the same time? You can reprogram reprogrammable logic as many
times as you want.

The ARM runs from ROM without needing the programmable logic (at least until
it needs to do a Tube transaction), so the ROM can just contain any soft
cores you want.

> Actually, you're probably onto something there. Presumably with a fast
> enough CPU it should be possible to emulate any of the period beeb
> coprocessors and for all intents and purposes it's indistinguishable
> from the real thing...

Indeed. Most 8 bitters could be handled this way.

> Just have a rotary switch on the back (say) which selects which copro
> you want prior to power-up (or fancy pushbuttons / LCD display, but I
> quite fancy something that just lives in a cheese-wedge box)

A *CONFIGURE option was my current thinking

 *CONFIG.TUBE
 *CONFIG.INTUBE
 *CONFIG.PROCESSOR 6502

and reset,
Sprow.