|
MrVCD
|
GameGear roms work on my Super Magic Drive (Sega Genesis copier) but gfx are bad and start button dont work!!!
 Posted: Sun Jun 25, 2000 5:52 pm
|
Hi,
I am the one with the Sega Genesis Copier called the Super Magic Drive. It can properly play SMS roms (even some demos and SF2!!)
and I just discovered that it plays GameGear roms too!!!!
The only problem is, the grafix are seriously fucked up and the start button doesnt work.
It seems to me that the start button in all games is automatically locked on(in effect, if a game starts, it seems that the game automatically has the start button locked, and i cannot play it any more cuz i cant deactivate the start button).
Is there any way to patch roms so that I can use the genesis start button and/or a way to keep the start button from being locked?
|
- Site Admin
- Joined: 25 Oct 1999
- Posts: 2029
- Location: Monterey, California
|
Posted: Sun Jun 25, 2000 11:52 pm
|
Quote > It seems to me that the start button in all games is automatically locked on(in effect, if a game starts, it seems that the game automatically has the start button locked, and i cannot play it any more cuz i cant deactivate the start button).
> Is there any way to patch roms so that I can use the genesis start button and/or a way to keep the start button from being locked?
There's no simple way around that I think. There may be a way that the genesis can read the start button in master system mode, that a patched rom could use, but I don't know about that offhand. If so, yeah, you could patch individual roms to use the genesis pad's start button... to do a proper job of it, though, you'd need to disassemble each rom and look for the routines that read the start button status, and work out a patch for that specific game. I suspect some roms would be easier than others.
|
- Joined: 28 Sep 1999
- Posts: 1197
|
Posted: Mon Jun 26, 2000 3:28 am
|
Quote > There's no simple way around that I think. There may be a way that the genesis can read the start button in master system mode, that a patched rom could use, but I don't know about that offhand. If so, yeah, you could patch individual roms to use the genesis pad's start button... to do a proper job of it, though, you'd need to disassemble each rom and look for the routines that read the start button status, and work out a patch for that specific game. I suspect some roms would be easier than others.
Hey, I just realized there's no way to pause an SMS game
running on a Super Magic Drive. How inconvenient.
This is slightly off topic, but I had a good idea for getting
around the start button problem, if you were running a GG game
on a real SMS - you could have the NMI subroutine toggle an
unused bit in RAM locations FFFC-FFFE (saying this as most all
games leave pages 1 and 2 fixed while swapping bank 3 around,
and the high-order bits for the bankswitching registers have
no use, as demonstrated by some games), and then modify the
start button reading code to check a bit in one of those
locations. (space allowing - some GG games have code that
executes right through address 0066h, because presumably it's
impossible to recieve an NMI if you've disabled the serial
comms feature)
Of course the palette hardware is still incompatible, so most
games wouldn't be that much fun to play. And certain games
expecting to read 00h from the GG serial port registers
would lock up, since they'd get FFh instead. (GP Rider comes to mind)
Now that I think about it, this solution is totally useless. :)
Weirdly enough, the SMS schematics would seem to indicate all
the right connections are there to read the extra buttons on
a Genesis style controller, but the actual controller ports
from the Z80's point of view don't allow that.
|
