This post was going to be a request for help, but I got it working.
I had trouble installing CHDK on a G1X (firmware 100g).
Here's what I did:
1 - Format 2GB SD card IN CAMERA
2 - Download STICK from http://zenoshrdlu.com/stick/stick.html
3 - Unzip, run stickx.cmd (this elevates to Admin; needed on x64 PC)
4 - Browse to path for a .JPG from the camera (drag-n-drop doesn't work)
5 - Insert a 2 GB SD card (64 MB didn't work)
6 - Click Download
7 - Scan for cards
8 - Install CHDK
9 - Wait for completion. Can take a while (allow 15 minutes)
10 - Eject card (safely)
11 - Set card lock
When I put the card in the camera, CHDK doesn't run, and the camera complains "Memory card locked".
CHDK wouldn't run until I used Windows File Explorer to copy files into the root of the SD card - these:
04/20/2022 01:13 PM 134,873 DISKBOOT.BIN
04/20/2022 01:13 PM 83,888 PS.FI2
04/20/2022 01:13 PM 11,701 changelog.txt
04/20/2022 01:13 PM 10,971 readme.txt
04/20/2022 01:13 PM 720 camnotes.txt
04/20/2022 01:13 PM 107 vers.req
For some reason STICK didn't copy those. Once I set the card to Unlocked, copied the files, then Locked it again, CHDK runs.