The last mini-computer I used was a GEC 4080, it had a chain printer which was rated at 600 lines per minute, I remember this because it was the identical speed to the printer on my own mainframe which was built 15 years earlier. Mind you the chain printer had a 64 character set whereas the drum printer could only manage 50 - no parentheses or brackets which are handy for high level language programming. Characters for 1/4, 1/2 and 3/4 are little compensation. Roger Holmes 1962 ICT1301 2006 MacBook Pro