Thanks, for the tip! I navigated through Chrono Crash as well as over to the RetroPie forums and was able to locate some help! I haven't done a lot of testing, but as of waaaaay early this morning, I was able to initially run
Rescue-Palooza using the Modules script that appears in the Ports section of Emulation Station when installing OpenBOR-6xxx. I went so far as setting up a PS3 controller but didn't start trying gameplay just yet.
I do know that the game won't allow the Van or Park levels to be consistently accessed, as per that forum. I also sideloaded a copy of OpenBOR for Android and saw the same thing. I'll likely beat those levels on a PC and convert the save state to Android/Linux readable format at some point. For now, here's all my notes, in case anyone else is interested.
=============================
Notes on OpenBOR for RetroPie
(and Windows... Android...)
by eskayelle
=============================
---------------------------
Hacking OpenBOR Save States
---------------------------
The following information was gathered via viewing and modifying TMNT: Rescue-Palooza! and TMNT: Red Sky Battle save states in a hex editor.
Open the .sav file in a hex editor, like HxD or xvi32.
Addresses (based on player one attributes only):
$00003C is number of lives. #$FF will give you 255.
$000038 is stage. In Rescue-Palooza!, #$63 is stage 99, the initial overhead view at game start.
$000034 is level. In Resuce-Palooza!, Looks like 4 is the very beginning, at the overhead stage.
$00005C is score.
Note that credits in OpenBOR appear to represent in-level (start in same place in level) continues and are located in the vicinity of the values above.
Further note that the above addresses presume a .sav state is created in Windows and the game run on a Windows PC.
In an Android APK environment (tested using a Samsung Galaxy S phone), these bytes are shifted forward 0x04 bytes.
So... a Windows-generated .sav state can't be used in Android until you relocate the bytes (moving them forward 0x04 places) using a hex editor.
This was specifically tested on Rescue-Palooza, but OpenBOR likely uses a very standardized format for save states.
----------
Games Tips
----------
TMNT: Rescue-Palooza!
1) Modify the lives byte in the save state (e.g., change to #$FF).
2) Van and Park levels do not work on Android or RetroPie. Beat those levels in Windows, and copy over that save state to your Android/Pi.
As per above, the data within the save state needs to be shifted 0x04 bytes forward for the save to work correctly.
TMNT: Red Sky Battle
The game seems to reset lives and continues after each level.
Changing the lives parameter in the save state does not seem to work, but...
Changing the credits (continues) parameter before starting each level (exit the level at the beginning, then make the change in a hex editor) may at least increase the in-level continues.
This becomes the equivalent of more lives.
-----------------------------------------
Setting up the latest OpenBOR in RetroPie
-----------------------------------------
From cyperghost's forum post on 10/5/2018, with edits by eskayelle via my install attempt (https://retropie.org.uk/forum/topic/19326/openbor-6xxx-openbeta-testphase/77):
1. Enter SSH terminal and type the following text (for newest -6xxx experimental branch):
wget http://raw.githubusercontent.com/crcerror/OpenBOR-63xx-RetroPie-openbeta/master/scriptmodules/openbor-6xxx.sh -O- | tr -d '\r' > /home/pi/RetroPie-Setup/scriptmodules/ports/openbor-6xxx.sh
2. Go to EmulationStation and select Configuration; select RetroPie Setup, or just type in an SSH terminal:
sudo ~/RetroPie-Setup/retropie_setup.sh
3. At the blue dialog box screen, navigate to P Manage packages.
4. Select exp Manage experimental packages.
5. Run down the list and select the opbenbor-6xxx package.
6. Select S Install from source.
7. Restart EmulationStation.
8. Go to the Ports menu and start the OpenBOR script (try the Module one).
If you get a black screen and a return to the EmulationStation menu after attempting to run one of the two OpenBOR scripts
(the .sh files, e.g., Game Engine and Module) that are now selectable in EmulationStation > Ports, the script may be trying to call OpenBOR instead of OpenBOR-6xxx.
To resolve this, press any button at the black screen with the grey box (just after selecting the script), and change the emulator to OpenBOR-6xxx.
Friendly reminder: Each OpenBOR .pak (the game) has to be individually configured to use a joystick. So, you'll need to use a keyboard, at a minimum, the very first time you configure a .pak.
I may take you up on that site in a bit. First, I need to beat this game one more time (or at least those first couple levels), then
Red Sky Battle, and then maybe look for this He-Man game a lot of people seem to love!
Thanks again!
