'S' is for... nothing!

Just a quick one... still progressing on Vulgus, chipping away at the unknown variables.

Indications are that the letter 'S' does... ABSOLUTELY NOTHING! I can't find any cross-references to it in the code, other than initialisation and updating a counter (max=4) when one disappears off-screen. A watchpoint in the MAME debugger doesn't reveal any accesses to the variable either.

Somewhat puzzling given that the other two letters do affect game play.

Random Vulgus picture for attention

I've been working on ROMSET #2 in MAME, so I decided to load up ROMSET #1 and see if that had any references to the variable. Took quite some time (two sessions) to get to the point where I could analyse the code in some detail - because of all the jump tables used in the game - but couldn't find any other references. Similarly playing the game didn't trigger the watchpoint.

I did however notice one difference in game play logic, and there are more. Interestingly ROMSET #1 allows 10-character names in the high score list, whilst #2 is only 3 characters. When I've finished the RE I will go back and analyse the differences in detail.