Someone mentioned a fabled R-Type TurboGrafx-16-to-SuperGrafx conversion in my Discord yesterday, so I asked Chris Covell if such a thing exists. It turns out, Chris was the person behind it. He started converting TurboGrafx-16’s R-Type to SuperGrafx in 2012, and made it to stage 4. The SuperGrafx’s extra hardware is used to reduce sprite flicker by doubling the maximum sprites on screen from 64 to 128. The hack also expands the screen size to full vertical height for PCE or SGX mode.
The work was interrupted by family events however, and the final product was never released. I asked if he could share it, even in its unfinished state, and today Chris shared the patch.
This is important because it’s the only conversion from TG16/PCE to SuperGrafx ever made, and it adds another playable SuperGrafx ROM to our small libraries. Just keep in mind that it only converts the first 4 stages.
Chris has authored a few other SuperGrafx creations as well: Battle Ace Cheat Menu Hack, Ghouls ‘n Ghosts Debug Menu Hack, Fractal Engine 2, and the Axelay Demo.
Unfinished R-Type (U) PCE/Turbo to SuperGrafx hack by Chris Covell
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This hack converts the US TG-16 ROM (unscrambled) of R-Type into
a bi-compatible PCE/SGX ROM. On a real SuperGrafx, flicker will
be greatly reduced, as the new limit to maximum sprites on-screen
will now be 128, as opposed to the TG/PCE’s 64.
I’ve also expanded the screen size to full vertical height on both PCE
and SG, so the game no longer needs to scroll vertically. To adjust the
vertical screen positioning, pause the game and hold I then press Up or Down.
This was a hacking project that I started in 2011, but abandoned
the following year, mostly because I became a father, and thus life
got too busy to work on a sustained project like this one.
(Each level has to have its scrolling, raster interrupt, priority logic,
etc. etc. hacked individually, you see.)
This hack is unfinished, and “works” to about level 4. It still has a
debug invincibility mode that can be activated by pressing Select during
gameplay.
This is distributed in the form of an .IPS patch. Apply the patch using
IPS patching software to an R-Type(U)ROM, (and rename it from .PCE to .SGX
if necessary for emulators/FPGA systems to activate their SGX emulation.)