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Message: 7052

Author: ian.rushforth

Date: 13/02/2017

Subject: Re: wraparound / mm

 

Incidentally, I don't believe that any corruption would occur in JSW if the up/down room exit code is disabled to allow Willy to wrap up/down in this way.

That would be harmless, because the Screen Buffer Address look-up table at #8200-FF is immediately followed by the Rope Animation table at #8300-FF. The first 30 entries of which holds values of '00'.

So even if the 'Draw Willy' routine did extend beyond the valid range of the look-up table, no harm could come of an attempt by the program to overwrite addresses with a high byte of '00' - the start of the ROM!

 

 

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