Air-Sea Battle and the Supercharger?

[+SpiceWare]

Just finished hacking my supercharger and have been having a blast. I used The Empire Strikes back as the "test", it wouldn't work before I did the mod, but works now when the switch is in the proper position.

 

However, Air-Sea Battle is misbehaving. The collision detect routines appear to be hosed - shots will either travel thru all targets w/out registering a hit, or they will hit a lower target but explode the topmost target.

 

Anybody else seen this? A search of the forums didn't turn up anything.

[Rob Mitchell]

Just finished hacking my supercharger and have been having a blast.  ... However, Air-Sea Battle is misbehaving.

 

Yeah .. Air-Sea Battle, Haunted House and a few other games do not work with the modified Supercharger.

 

Chad Schell knows what causes this problem .. and the Cuttle Cart hardware/ software corrects this problem for Cuttle Cart owners.

 

But this doesn't help you .. Still ASB and HH are common carts anyway.

 

Rob Mitchell, Atlanta, GA

[+SpiceWare]

Thanx! I was concerned I might have done something wrong during the mod.

[+SpiceWare]

Found a solution on the Stella list - Air-sea battle on SC - solved!

It turns out that Air-Sea battle reads the images of the collision  

registers at $00/$01, as opposed to $30/$31.  It looks like the SC  

interferes with the mapping of the read-registers, maybe because  

they overlap the write-registers there?

 

 

At any rate, patching the code to use the images at $3x makes it  

work on the supercharger.

 

Specifically for Air-Sea Battle,  

offset $00b9:   $00->$30

offset $00bd:   $01->$31

offset $004a:   $00->$30

 

Also turned up references to Haunted House, Space War and Ghost Manor not working, as well as Breakout which must be doubled up to a 4K image to work.

[+SpiceWare]

didn't work

 

no difference changing locations 00b9 and 00bd. Location 004a has a 01, not a 00, and changing it causes a crash. I ran it thru Distella and it looks like the 004a should have been 024a, but changing it didn't help either.

[cschell]

The collision detection problem with the Supercharger and some games is caused by a bus timing error on the Supercharger's part. That much I know, but I don't know why that bus timing error creates a problem in a few games but not in others.

 

Unfortunately I don't think the bus timing error can be fixed, but altering the ROMs seems like a clever way around the problem. Too bad the fix you mentioned above didn't work.

 

Chad