IBM Selectric-based Terminals

From: Christian Gauger-Cosgrove Sent: Tuesday, December 15, 2015 4:25 PM 2741s are OK. I much preferred the 2740, though. We had those at the Computer-Assisted Instruction Laboratory at the UTexas School of Education (Student job, autumn 1969-autumn 1970), but only 2741s at Ohio State. On the 2741, ETX is tied to the Return key. That made correcting a class of errors in Coursewriter III much harder: Incorrectly inserted labels could not be removed by the author, but only by a systems programmer editing the file on disk. On the 2740, there was a bank of 6 buttons to the upper right of the Selectric keyboard. I only remember 3 labels, because the other 3 didn't do anything special under Coursewriter III or APL\360, but the important ones were EOT, ETX, and EOB. With judicious use of these, newlines could be inserted into the entered text at will, allowing for the selection of labels surrounded by empty lines. It also allowed for security by obscurity: The supervisor password on the Coursewriter III system was 0x4040404040404015, which could not be entered on a 2741. Ah, the Good Old Days(TM)... Rich Rich Alderson Vintage Computing Sr. Systems Engineer Living Computer Museum 2245 1st Avenue S Seattle, WA 98134 mailto:RichA at LivingComputerMuseum.org http://www.LivingComputerMuseum.org/