I have prepared a modding walkthrough document here:

• PCU (Project Carousel USB)
• Custom Firmware for mod without FEL or UART (aka: THEC64 X-Windows Mod)
• TheC64 Carousel Game Tool
• FEL-mode Hack - No UART needed
• UART Hack - How to mod the c64 mini to add extra games

These are the main threads outlining what is presently the most popular and well-documented path to mod your c64 mini:

• http://thec64community.online/thread/76/thec64-modding-games-little-guide
• http://thec64community.online/thread/4/modding-thec64-mini?page=7

• https://www.facebook.com/groups/209280506324242/permalink/229787937606832/
  • Paolo DiscoBear Vaccari provided a set of extra 45 games that can be added to the menu
• https://www.sendspace.com/file/h3ddyc
  • A direct link to download Paolo's extra 45 games
• https://www.facebook.com/groups/209280506324242/permalink/315301865722105/
  • Paolo's updated set of now extra 84 games that can be added to the menu
• https://mega.nz/?fbclid=IwAR1rS1AmIMr2lF0tJ9Vw3nFE4RQs-QAcBvsrN7cJG8cTq0Xl2KGJB1_rpaw#!0IJ0kSIY!OY9jVlUJwmeMNG_ZtWfBkesrObYRWmIsOHMUnJEj1us
  • A direct link to download Paolo's extra 84 games (list of games atPaolo's USB File Loader set)
• http://thec64community.online/post/2063/thread
  • The actual limit of the carousel items are 150. Firmware 1.2.0 added “Galencia” - one title above limit with Paolo's set, so one title has to be removed for this to show up (e.g. THE64-HALL-OF-FAME.tsg has to be renamed).
• https://www.facebook.com/groups/209280506324242/permalink/225052331413726/
  • Mike Paull's mod effort, showing how he fed the UART cable through the case
• https://www.facebook.com/groups/209280506324242/permalink/217174305534862/
  • a thread with Mike Paull's choice of UART connector
• http://c64minicommunity.freeforums.net/thread/79/adding-uart-connector
  • Mike351's walkthrough on adding the UART connector
• http://thec64community.online/thread/80/replacing-stock-c64-kernal-1541
  • Mike351's walkthrough on replacing the kernal
• http://thec64community.online/thread/100/usb-gamepad-ninento-snes-controller?page=1&scrollTo=592
  • Info on joystick mappings

• https://gurce.net/oldforum/d/95-information-on-the-a20-cpu.txt
• http://linux-sunxi.org/Retro_Games_Ltd_RGL001
• http://thec64community.online/thread/4/modding-thec64-mini
• https://www.facebook.com/groups/209280506324242/permalink/216680592250900/

I had references to these on the Hardware Compatibility page here:

• Compatible hardware#joystick-to-db9_modding

This is a method I'm still pondering. I shared some thoughts on it via twitter:

• https://twitter.com/GurceIsikyildiz

I still haven't seen it through yet, so if someone wants to beat me to the finish-line, they're most welcome to :)

• https://www.facebook.com/groups/209280506324242/permalink/216918578893768/