Wireless print is strings of “commands”

My new Epson printer is working fine on Wi-Fi from my iMac (Big Sur) but when we try and print from our second iMac (High Sierra 10.13.2) on the same network it prints pages of coding/commands/whatever. No queued print jobs. Does the older computer need something it doesn’t have - a driver, or some preferences changed, or what? Sorry to sound vague but we have no idea what the problem is!