Date   : Mon, 18 Jul 1994 14:52:24 +0100 (BST)
From   : clr1@...
Subject: Re: benchmarks

> It depends somewhat on how you're emulating the keyboard etc., but you
> probably need to get some of the system VIA done, bits of the CRTC and
> video ULA and ignore the reset of memory-mapped IO.  If you want to
> see the prompt, you're obviously going to have to implement some
> sort of screen IO too.

Oh dear... I've got a basic mode 0 screen mapping system going though.

> You'll also need to deal with the paged ROM select switch.

Not too bad.

> [ As an afterthought, the reason you need some sort of keyboard emulation
> is because the OS scans the keyboard for pressed keys (eg, shift and ctrl)
> and also the power-up option DIP switches.  If you get these wrong, weird
> things can start happening when you're implementation is otherwise OK.

Doesn't it go beeb as well? What about that? I suddenly thought of that 
in bed last night. Anyway, it doesn't really matter to me at the moment 
because I can't load the OS in anyway due to my inability to allocate 
65536 bytes of memory...

+-------------------+-------------------------------------------------+
| /-- |_| /-- | (~  | "And the driving is like the driving of Jehu,   |
| \-- | | |   | _)  | the son of Nimshi, for he drives furiously."    |
+-------------------+-------------------- Second Book of Kings 9 v20 -+