This bug just got more interesting!
Richard, the 'From Top to Bottom' Rope Bug just got even more interesting again!
I think I have managed to come up with a code change which precludes Willy escaping 'from the top to the bottom' of a room that has a rope and the Up Exit set to itself.
On top of the POKES provided in the disassembly, which reset the values at #9396 and #939A in the Rope-drawing code from 12 to 15 ('#0C' to '#0F' in hex), I have changed the value of a single byte. (Actually, for consistency I changed two bytes, from the same old value to the same new value, but only one of the two is directly relevant to the matter at hand.) My initial attempt at a new value for the pertinent address proved to be insufficient for the task, but I managed to identify why, and then resolved that by tweaking the new value accordingly.
This may seem a bit cryptic at the moment, and I promise that I will reveal all soon. But before I provide a full explanation, I would like to invite, nay challenge (if not defy ) jetsetdanny - and anyone else who might care to try - to confound me, by opening up the attached file and succeed in jumping off the top of the starting room (On the Roof), via the rope!!
And then, once you have (hopefully!) failed to do so, please read the spoiler box below for an even more peculiar revelation...
Edited by IRF, 22 September 2016 - 12:31 PM.