[stella] Supercharger problem games?

Subject: [stella] Supercharger problem games?
From: "Darrell Spice, Jr." <dspice@xxxxxxxxxxxxxx>
Date: Thu, 07 Aug 2003 18:26:21 -0500
Just picked up a Supercharger via ebay and mod'ed it. I've tried 135 different games so far and found 3 with problems:

Air-Sea Battle - shots either don't register or a shot on lower row blows up ship on topmost row
Canyon Bomber - screen rolls like crazy
Code Breaker - screen rolls, but differently than Canyon Bomber.

I've done some research and found a possible solution for Air-Sea Battle here on the biglist -

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

I tried this, but no luck. Running Air-Sea battle thru Distella it looks like the 004a should have been 024a, but changing that didn't help either.

The Air-Sea Battle search also turned up a few other games with the same problem: Haunted House, Space War and Ghost Manor.

I've not found any reference to the scrolling screen problem, though I have seen references to Canyon Bomber running OK on the Supercharger. Any ideas? I'm using a Commodore 1084S with an SVHS VCR as the tuner and am getting a great picture(though I do plan to build the audio/video mods later). I always used the monitor with my Amiga at PAL resolutions, and some of the games I tested included PAL games - adjusting the monitor allowed me to see the whole screen.

-- Darrell Spice Jr. --==> http://www.spiceware.org <==-- * Emulators for OS/2! Stella = Atari 2600 ColEm = ColecoVision MasterGear = Sega Master System, Game Gear, SG1000, SC3000 VGB = Game Boy, Game Boy Color, Super Game Boy * OS/2 programming info also available.

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