Resource centre for ZX Spectrum games
using Manic Miner and Jet Set Willy game engines
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Message: 5861
Author: andrewbroad
Date: 30/06/2006
Subject: Re: Technical question (#9C00-9C3F)
Daniel wrote:
>It's just a few lines of assembler source-code (in ASCII text
> A question to the technically-knowledgeable among you:
>
> What is the function (if any) of the code found at #9C00 - #9C3F in
> the original "Jet Set Willy"?
format, with a few weird characters between lines). It's quite safe
to overwrite it.
JR NZ,ENDPAUSE
INC E
JR NZ,PAUSE
INC D
JR NZ,PAUSE
Evidently this was used to assemble the code at #8AD9-8AE0, which is
part of the loop that checks for key-presses while the game is
paused.
The DE register-pair holds a 16-bit value that is incremented on
each pass through this loop (as we see in the code above), so that
the screen can be recoloured every time DE == 0.
--
Dr. Andrew Broad
http://geocities.com/andrewbroad/
http://geocities.com/andrewbroad/spectrum/
http://geocities.com/andrewbroad/spectrum/willy/
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