The problem is that when we were working on Mac OS 8/9, we didn't include the frameworks for that type of thing, as video streaming was the big focus when we introduced the server features and eventually QuickTime. However, what you can do is VNC into your Power Mac running OS 9 from another modern-ish Mac or PC or even your phone and have the screen recording going on the newer system or recording on your iOS or Android device. Outside of recording a VNC screen, it's not possible without hardware, so you would need a capture card. We did some early stuff with the TAM (Twentieth Anniversary Mac), but a lot of that was done through hardware versus software for recording. The frameworks just aren't there without involving hardware. There was a company, I believe, that developed Snapz Pro, which had some basic screen recording and a custom library, but I never really used it, as screen recording wasn't a thing back then outside of television or post-production stuff at Pixar and movie studios. But even back then, Macs really weren't a part of the pie in that industry, as it was dominated by Silicon Graphics systems. Good luck!!!