Date   : Tue, 13 Feb 1996 22:08:49 +0000 (GMT)
From   : Tom Seddon <T.W.Seddon@...>
Subject: Re: Tape protection schemes (was: Decoding BBC tapes...) 

On Tue, 13 Feb 1996, iain (i.) barker wrote:

> It struck me a few years ago that compression is a reasonably recent
> addition to runtime code (eg PKlite).  Something like this would have
> done wonders in the BBC days.  Does anyone know of any BBC programs which
> used compression (albeit relatively simple given the low processing power
> available)?

BugEyes II, Future Shock, and several other games used RLE on their title 
screens. They also used the 'different filename every block' protection 
method, giving you a nice message while the program loaded. In fact 
virtually all Art Crew games used to do this. (Does anyone know what 
happened to the Art Crew by the way? Their games were always really good, 
especially those nice chunky graphics)

I suspect many games used to use compression for their data, although this
is only a guess. I often wondered how you'd compress data (eg sprites and
things) whilst keeping the game speed up,given the BBC's relative
slowness. If anyone has any pointers, I *might* get back to work on my BBC
Micro conversion of Dynablaster, which I started last summer :-) All the
sprites are there, it's just that I've worked out that if I keep the
number of sprites to the *Absolute* minimum, I'll still only have 1.5K
left for all the code... 

--Tom

     .                     ** Tom Seddon **                     .
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