Willy disassemblies in hexadecimal

[IRF]

I suppose it depends on whether you consider the disassembly to be an accurate description of the original JSW code, or a useful tool for future developers of JSW games.  It's kind of both, but the former is its primary purpose (it doesn't catalogue the various quirky features of the game code that don't actually manifest themselves in the original game).  That said, it's a modest and useful amendment that I proposed.

 

It's Richard's call ultimately.  :)

[IRF]

Richard,

 

Here are another couple of suggestions for the 'Trivia' section of the disassembly:

 

(1) It is possible for Willy to fall a greater distance than the height that usually kills him (4 cell-rows), IF the fall passes through the bottom of one screen and into the next AND IF he hasn't already fallen by more than the safe distance (as indicated by the change in pitch of the 'Willy is falling' sound effect) by the time he has reached the bottom of the first screen.

 

To illustrate the point, position Willy on the ramp in The Orangery, near the top (but not so close that he can jump to the next room above), and jump leftwards.  Willy will land fatally on the ramp, having exceeded the safe fall distance.  Now walk Willy up to stand on the ramp of Conservatory Roof (effectively the same ramp), and jump left again.  The same manoeuvre is survivable because the transition to the screen below 'interrupts' his descent, thus resetting the 'fall counter' (and associated sound effect).

 

(2) If Willy falls off the bottom of a screen, where there is a Fire cell at the top of the screen directly above the point where he is falling, then he dies upon contact with the bottom of the screen (and is reset to his starting position within that screen).  (Why this happens exactly is unclear, but possibly the routine that kills Willy if there is a Fire cell in either of the cells directly underneath him, could be 'wrapping round' to check the cells at the top of the screen, whenever he is occupying the bottom two cell-rows?  It doesn't occur if there is a guardian at the top of the screen directly above him.)

 

A good example of this effect in action is the right-hand side of Under the Roof, where the front of the 'Nomen Luni aeroplane' occupies the top of the screen and is comprised of Fire cells.  In this case the effect is most fortuitous for Willy, as he would otherwise enter an Infinite Death Scenario falling repeatedly down (beyond the safe fall distance) into A Bit of Tree!

Edited March 18, 2016 by IRF

[IRF]

It's just struck me that the Pokes section of the Manic Miner disassembly could do with a Poke that stops crumbly platforms from crumbling. Could that be achieved by NOPping out all the commands that call up the routine at 35770?

Edited March 25, 2016 by IRF

[Spider]

It's just struck me that the Pokes section of the Manic Miner disassembly could do with a Poke that stops crumbly platforms from crumbling. Could that be achieved by NOPping out all the commands that call up the routine at 35770?

I've not checked, but it (could) cause problems for instance Central Cavern you'd not be able to get down from the top platform if nothing was crumbly :D

[IRF]

Ah, I hadn't thought of that.

 

Still, it could be useful for other games that use the MM engine.

[Spider]

Ah, I hadn't thought of that.

 

Still, it could be useful for other games that use the MM engine.

Yes useful for non standard games. :) An alternative would be to make a few 'gaps' where appropriate. Screens such as 'The Vat' might need more work though. :)

[IRF]

Or if it was a quirky game, provide an 'innocent looking block' to jump through! (Does that work in MM?)

[Spider]

Or if it was a quirky game, provide an 'innocent looking block' to jump through! (Does that work in MM?)

They are 'treated' the same as Water cells usually :) At least as far as I read the code regarding "passing through things"

[IRF]

They are 'treated' the same as Water cells usually :) At least as far as I read the code regarding "passing through things"

So providing a single Earth cell two rows above the crumbly floor should allow Willy to jump through in quirky, logic-defying fashion!

[IRF]

[Pedantry alert!]  I've just noticed an error (I think) in the disassembly.

 

The entry at #8820-8827 is described as "Copy the attribute bytes for the top two-thirds of the title screen from 9800 to the attribute file".

 

In fact, the LD BC command at #8823 copies the attribute bytes for the entire title screen from #9800 AND #9A00, as determined by the operand #0300.

 

(So it sets the attributes for the bottom third of the title screen, as well as for the playing area.)

Edited April 20, 2016 by IRF