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Member Since 09 Apr 2015
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In Topic: Pokes for Fixing the Cell Graphics Bug in JSW

19 November 2017 - 01:55 PM

Have you checked whether the Cell-Graphics Bug affects any cavern elements in Manic Miner?


I have, and the answer is no, it doesn't.

In Topic: Pokes for Fixing the Cell Graphics Bug in JSW

17 November 2017 - 08:16 PM

Has anyone noticed the instance of the Cell Graphics Bug affecting the Fire cells in 'A Bit of Tree' in the original JSW?


Can't say I have - time to update my JSW disassembly TODO list. :)


By the way, I checked and this is the only instance of a non-conveyor tile being affected by the Cell-Graphics bug.

In Topic: Sources

15 August 2017 - 07:26 PM

One advantage of generating an ASM file from the SkoolKit source files is that it retains all the annotations. You can also generate an ASM file that includes several bugfixes:

skool2asm.py -f 2 jsw.skool > jsw-bugfixes.asm

In Topic: Sources

15 August 2017 - 05:06 PM

Did you mean it should be possible to generate an as from the skoolkit files?


Yes, you can generate an assembler-friendly ASM file from the SkoolKit source files for MM or JSW. In fact, that's one of the main points of SkoolKit - you can use the same source files to generate both the HTML disassembly and an ASM file.


You will need to download SkoolKit - for which you'll also need Python, version 3.4 or later - and use skool2asm.py to convert jsw.skool into jsw.asm (for example):

skool2asm.py jsw.skool > jsw.asm

I've successfully tested the output of skool2asm.py with pasmo, SjASMPlus and z80asm (the assembler that comes with z88dk), but it might work with other assemblers too.

In Topic: The AND, OR and XOR instructions

12 November 2016 - 03:01 PM

Is there any good reason (e.g. in terms of the effect on the Flags, perhaps?) why the original game engine uses an XOR command at #91FB, instead of an OR?


It's the instruction which merges a guardian's INK colour and BRIGHT value (Bits 0-2 and 6) with the PAPER colour (Bits 3-5) of its host cells.

No, there's particular reason to use XOR instead of OR here. As you've noted, there's no difference in the resulting value in the A register, and there's also no difference in the effect on the flags (which are not checked anyway).