Willow Hack - Almost There

The main part of this hack - setting aside some SRAM to save to and load from, the actual routines for accomplishing this, and the basic interface to select from 3 slots where to save or load - is complete.

I still need to write a routine that displays Willow's stats for each save game, and do something better than SELECT+B in order to access the save menu. There is also a bug where the background music isn't restored after leaving the save menu.

I also did a few kludges to make things work, such as shamelessly copy/pasting some code from other parts of the code without knowing exactly what the function calls did. Seems to work fine though.

I also need to check if I've overwritten any code that shouldn't be. Fortunately (I noticed) the assembler does export symbols from the source. This means that any labels I've used in the source code are noted down along with their memory locations in the ROM. By placing labels at the end of functions and data tables, I can compare with the original disassembly and find out if I've overrun any code.

I also noticed and rooted out a little bug where the stack head kept moving up after selecting continue. Turns out the original code forced a stack reset which I failed to include (yes, copy/paste). Although there seemed to be no ill effects right off, it might have caused problems after the player continued 20 or so times.

However aside from the savegame text and a few bugs, there are a few things I want to add before I call this patch finished and release it into the world.

I want to add the name of the area into the save game, just so the player knows more-or-less where he left off, and a percent complete value would be nice. I suppose the calculation for percent completed would be computed from the items Willow has acquired. Then there's a minor hack to the saver/loader routines which should use a checksum to verify if the savegame is valid or corrupt.

One last thing, I'd like to add my name into the credits on the PRESS START screen, but the data is tightly packed with no free memory right after it, so my last hack will entail either moving that bit of data into some place more agreeable, or add and extend the "string" writing code to allow jumping to another location in memory. Right now I've just shamelessly replaced the TM & © "LUCASFILM" with "ENDERSOFT".

For now, here's what the selection screen will look like. The data is actually a mock-up - no values are read from SRAM - but the screen is actually running off the emulator (i.e. no Photoshop tricks)