Date   : Fri, 06 May 2005 14:48:39 +0000 (GMT)
From   : "Thomas Harte" <thomasharte@...>
Subject: Re: Chuckie Egg - better patch (and some mysteries solved!)

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> To be clear, you're talking about the Electron version, I assume?
> 

> It may sound a small point - but that is a rewrite, so I err .. "classi
fy"
> it entirely separately from the BBC release Rich et al have been p
laying
> with - as the pokes and stuff won't work without modification.


Yes, I meant the Electron version, having been unaware that it was a r
ewrite. I'd just assumed that the reason for the 1 colour sprites was eas
y BBC/Electron compatibility but I guess that isn't the case.

I did on
ce investigate the code of Chuckie Egg with a view towards putting togeth
er a 'multiplexed' version (i.e. a version using my emulator's almost nev
er used power to stick new graphics over old games) but found it impossib
le because it seemed very much as if the game uses the ROM text output fu
nctions to throw its sprites onto the screen.

Two possibile conclusion
s occur. The first is that I was mistaken. This is very likely as I'm rub
bish with other people's code.

The second is that I was right and the 
developers just found that to be an expedient way of doing things. A vari
ation may be that they found it to be a more speedy way of doing things E
lectronwise, what with ROM accesses being always clocked at 2Mhz but RAM 
in modes 4-6 only 1Mhz.

> I've seen copies of the Electron version wit
h both the AnF logos (both on
> ebay at the moment, in fact) - but not u
nder the Pick & Choose label.  I'd
> be quite interested in a decent siz
ed scan of the inlay card and tape, if
> that might be possible?  I'm no
t sure there's much chance of it turning up
> on ebay any time soon ...


I may be able to do this at some point, but not in the next two months
 for the probably common reason that my Electron stuff is in the loft at 
my parental home and I'm busy completing my bar qualification...

A qui
ck Google image search provides this though: http://www.clive.nl/images/2
3708.jpg

Imagine that with an 'Electron' banner across the bottom righ
t instead of Spectrum. I have the feeling it wasn't yellow either. My bra
in is suggesting blue but I can't picture it and have possibly the worst 
visual memory since time began.

> I wonder if it's possible to compare
 the various releases byte-by-byte, to
> see if there are any difference
s in the files.  Something akin to the old
> DOS comp command, which wou
ld flag up if a version had been recompiled when
> it was re-released ..
  or perhaps something that would generate a checksum
> for a file which
 could be run against each release of the same file to see
> if they tal
ly.

There isn't any need to calculate a checksum, the tape FS already 
has one in the header of every data block (i.e. every 256 bytes of file d
ata). It's of the standard CRC16 variety.

This makes me think I should
 hurry up with the full system debugger that ElectrEm Future has been wor
king towards.

> > Don't do that - it's rubbish!
> > 
> > 
> > -Thom
as
> 
> I trust you're talking about sleep ... ;)
> 
> If you're talk
ing about Chuckie Egg, then I may have wasted a small part of
> my life 
of late ... !

I'm talking about the ZX Spectrum version, which I absol
utely hate. I don't know exactly where the programmers lived, but that ce
rtainly isn't how physics works in my world. Or Newton's (with a hint of 
Euiler) for that matter. Makes the whole thing an unplayable mess in my o
pinion, although I know that it's highly regarded by Spectrum types so I 
suppose it must be a taste thing.

-Thomas

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