Date   : Thu, 07 Sep 2000 12:42:42 +0100
From   : russell.marks@... (Russell Marks)
Subject: Re: yet another BBC emulator? (New MESS BBC emulator will have 8271 d isc support)

James Fidell wrote:

> Quoting Jefferyes, G S (g.jefferyes@...):
> 
> > Well yes.. I wanted to write my own BBC emulator, so I found a good place
> > to write it, and now MESS (http://mess.emuverse.com) has a BBC driver.
> 
> I think this is a good way to go.

I have misgivings about MESS myself, but it does get widely ported
which is nice.

> For the first time in five years or so, I've actually found some time
> to spend on Xbeeb, too, so I'm currently working on reviving that, more for
> my own interest and satisfaction in finishing what I started  than anything
> else.

I did some minimal hacking on xbeeb 0.3.5 (not quite the latest
version, it seems, and certainly not now :-), but hopefully not too
far off?) which might possibly be of interest. Here's what I did (from
change log entries in the diff I kept):

> + * src/Keyboard.c: changed keyboard support to be set/unset rather
> + than keeping count of presses/unpresses. This should save needing
> + the keyboard kludge added earlier, so I've removed that.
> +
> + * src/Bitmap.c: fixed lots of bugs in 16bpp support. :-)
> +
> + * src/Bitmap.c: added 16bpp support (i.e. now works with MITSHM).
> +
> + * src/Bitmap.c: should have been >=312, not >312 (at least, I presume
> + so - it cured a segfault ;-)).
> +
> + * src/Bitmap.c: kludge to halve frame rate. Seems to be needed to
> + stop the heavy bitmap output demands from making it painful to use
> + (even with MITSHM in 8bpp). Still runs at 25 fps in mode 7 though,
> + to avoid blinking problems there otherwise. :-)
> +
> + * src/Keyboard.c: kludge to stop it screwing up badly if keys are
> + let go before being pressed on startup. Note this can still happen
> + with things like the commonly-bound Alt-Tab, so this needs doing
> + properly at some point (i.e. should take notice of EnterNotify or
> + whatever).
> +
> + * src/KeymapStrict.c: also allow Meta_L/Super/Hyper for Control
> + key. This means e.g. on Linux/XFree you can use Alt or (on a W95
> + keyboard) a Windoze key. Also allow Meta_R for shift-lock.
> +
> + * Now works in 16bpp, as long as you compile without MITSHM
> + enabled. Which makes it agonisingly slow, of course. :-) Hope to
> + fix that (at least for 16bpp) soon-ish...
> +
> + * Added speed control. I think in some cases it's waiting for two
> + frames where it should wait for one, but apart from that it seems
> + to work.

-Rus.