The ATI XClaimVR 128 will work with System 7 and has video capture via the excellent ATI Theater chip, it does NOT support OS X for capture, only VGA video out. I don't recommend using old Macs (or old computers in general) for analog video capture though. The older Powermacs don't have the I/O throughput to capture full frame video lossless with the stock SCSI. You need a UDMA133 IDE hard drive controller and matching modern 7200rpm drive.