These are the steps I took..."
- Install RetroArch onto your device if you don’t already have it.
- Download the “Arcade(MAME)” core. Don’t use the MAME cores with years attached.
- Check out and download this archive: CD-i member JoKu_The_Darksmith pointed out* that only the hash file and blank(dummy) files from the provided zip you need if you already have a RetroArch setup. The archive is here: https://mega.nz/#!pWx2nCDK!FCatjANHPhHjsZgoLetlr62Vqc3RyzIwiEcjWcpeuUE
- (If the link doesn work anymore, contact Interactive Dreams by commenting below)
*It includes the cdi.xml hash (place in RetroArch's /system/mame/hash/ folder) and the CDI_blank.zip containing the required dummies.
Rework your zip file to only contain the path and folder "/system/mame/hash/" the "Hash" folder within MAME in the System folder is the only thing you need, and the "CDI_Blank" folder. The step with the keyboard overlay is because you don't have a bluetooth controller and obviously the keyboard to "TAB" into the MAME UI.
Given that you already have RetroArch Installed, place the "Hash" folder (from the download) in the "mame" folder within the "System" folder. [RetroArch/system/mame/hash]
Now lets assume you already have the CD-I game which is in .CHD format. If it's not and is in bin & cue, look into a program called "CHDMAN" to convert (check our MAME CD-i tutorial here). For reference let's say we have "Hotel Mario (1994)(Philips)(US)[!].chd", go into the "CDI_Blank" folder and copy the zip that matches the game you obtained, in this case its "hotmariou.zip" which is short for "Hotel Mario". It was easy to pick out. IF your CHD is named differently open up the XML file in the "Hash" folder and rename your rom/.chd file to what it shows in the XML. When you load "hotmariou.zip" in mame, IT WILL BE LOOKING SPECIFICALLY for "Hotel Mario (1994)(Philips)(US)[!].chd" If you've ever played a CHD game in MAME this is how mame works with CHDS, it loads a zip that links to the CHD file.
Your Rom files can be placed ANYWHERE, it DOESN'T have to be in the RetroArch folder it could be on a usb stick if you wanted, BUT IT DOES HAVE TO BE WITHIN A FOLDER CALLED "cdimono1" and within that folder have the 3 CD-I bios files (cdimono1.zip, cdimono2.zip, and cdibios.zip)
- The ZIP contains two archives: RetroArch.zip and CDI_blank.zip.
- Extract the contents RetroArch.zip to the root of your phone’s internal memory or SD card. Can merge these folders with your own if you have your own RetroArch setup.
- Extract CDI_blank and grab the zip(s) that correspond with the game you are trying to emulate. Place it in the “RetroArch/roms/cdimono1/” folder**. Check out the “readme.txt” file in that folder for more help.
- Add cdimono1.zip to the “roms/cdimono1/”. Some games may require cdimono2.zip and/or cdibios.zip. Add those if necessary.
- Place your game CHD into “roms/cdimono1/”
- In RetroArch, click “Load Content” and navigate to the blank game.zip you placed into the cdimono1 folder**. Do not directly select the game CHD. Click “Load Archive”. The turquoise screen should appear for around 10 to 20 seconds depending on your device specs.
- I did not include the cdimono1.zip, cdimono2.zip, or cdibios.zip. You know the drill.
- Once you get to the CD-I Player menu, click the RetroArch (Space Invader) icon.
- Navigate to “Onscreen Overlay/Overlay Preset/keyboards/US-101/US-101.cfg” Resume the emulator.
- If the keyboard doesn’t fit your screen properly, try hitting the button next to the RetroArch button to change the keyboard’s orientation.
- Press the tab key. Click “Input (This Machine)”. Use the keyboard arrow keys to navigate to “Mouse Button 1”. Assign it to the “Enter/Return” key by pressing it. Mine Shows up as “ENTER CPSLOCK”, but it works fine. Navigate down to “Return to Previous Menu” and then to “Return to Machine”. If you press the Esc key, the emulator will close.
- Use the arrow keys to move the CD-I mouse cursor to “Play CD-I”. Press the Enter key. The turquoise screen should appear for a few more seconds and your game should startup.
**What my folder looks like:
ROOT:/ROMS/CDI/cdimono1
->cdibios.zip
->cdimono1.zip
->cdimono2.zip
->hotmariou.zip
->Hotel Mario (1994)(Philips)(US)[!].chd
Using the most recent mame core and default settings simply "Load Content" to "hotmariou.zip" then you will see the CD-I player screen in a moment click the "Play" triangle on the menu you see, IF you have a USB mouse attached MAME will automatically map the controls to the mouse, nothing needed to be done. Assuming you are using a controller (Xbox One), go into the in-game "MAME GUI you can map the mouse to the Left Analog Stick. Its also important you change those sensativity settings from 100 to 10!
*MAME GUI -> Input (this Machine)
Mouse Button 1: Joy 1 A (personal choice)
Mouse Button 2: Joy 1 X (personal choice)
Mouse X Analog: Joy 1 LX (Just press left analog stick RIGHT)
Mouse X Analog Dec: LEFT (default - or press LEFT on D-PAD)
Mouse X Analog Inc: RIGHT (default - or press RIGHT on D-PAD)
Mouse Y Analog: Joy 1 LY (Just press left analog stick UP)
Mouse Y Analog Dec: UP (default - or press UP on D-PAD)
Mouse Y Analog Inc: DOWN (default - or press DOWN on D-PAD)
*MAME GUI -> Analog Controls
Mouse X Digital Speed: 2
Mouse X Reverse: Off
Mouse X Sensitivity: 10
Mouse Y Digital Speed: 2
Mouse Y Reverse: Off
Mouse Y Sensitivity: 10
[Thanks, sk3tchalpha, JoKu_The_Darksmith]