Thank you DieHard, coachla & GaryN. I tried it with M-Audio Firewire 410 and Edirol UA-25 on OS 9.2.2 with Logic 4.8.1 and Studio Vision Pro, but it didn't work. 410 worked fine with OS 10.3. Audio interfaces for OS 9.2.2 are being sold relatively cheaply at auctions in Japan. I bought Emagic's Audiowerk for $15 and plugged it into my Mac, and Audiowerk responded to Logic. I had an Audiowerk over 20 years ago and knew how to connect. My OS 9.2.2 is a G4 that I bought in 1999 and sat in storage after using it for 10 years because the SCSI display broke. My main Mac is a Mac Book Pro 2015, and I use Pro Tools Ultimate with HD OMNI and HD Native Thunderbolt with 96. I used Mojave as my OS for a long time. I updated to Big Sur once, but all the features became slow, so I changed back to Mojave. I have been using Logic for 5 years, and this time I wanted to learn from the past and start composing with Logic again. I also have feelings for Vision. People here love OS 9. I'm glad I met my friends. Thank you very much.