This is Digital Equipment Corporation's DECwriter II hardcopy operators' terminal. It was designed as a replacement for Teletype Corporation's ASR-33 . Unlike the ASR-33, the LA-36 contains no paper tape handling hardware.
Unlike the ASR-33, the LA-36 utilises all solid state logic and has an electronic keyboard. The only mechanical components are the 9-pin print head, the print head motion mechanism, and the paper line feed hardware.
The line feed motor is a stepper mechanism; the head motion motor is an analogue servo motor mounting a pulse generating slotted wheel, the pulses from which are used to derive the location of the head. The printing ribbon is advanced by means of a mechanical linkage to the head positioning motor.
The printer mechanism uses a dot-matrix technique to print 132 columns of text across standard 14 inch computer forms. Both upper- and lower- case were handled in the standard unit; optional character sets (e.g. APL) were available as an option and selected via a switch on the keybard. The width of the paper feed is variable by moving the right-hand paper tractor.
Normal printing speed is 30 characters per second using a communications
rate of 300 bps. Incoming data is bufferred so characters are not lost
during a carriage return operation. Following a carriage return, the LA-36
is capable of printing at a catch-up speed of 60 cps for short periods. Some
LA-36es were modified to allow printing at the 60 cps full- time, but in
doing this fill characters or delays were required to compensate for print-
head return time.