IBM 2780

The IBM 2780 and the IBM 3780 were devices developed by IBM to perform Remote Job Entry (RJE) functions. They communicated with the mainframe via Binary Synchronous Communications (BSC or Bisync).

The 2780, first shipped in 1967, came in four models. The Model 1 could read punched cards and transmit the data to a remote host computer, and receive and print data sent by the host. The Model 2 added the ability to punch card data received from the host, The Model 3 could only print data received from the host, but not send data. The model 4 could read and punch card data, but had no printing capabilities.

The 2780 used a dedicated communication line at speeds of 1200, 2000, 2400 or 4800 bits per second. It was a half duplex device, although full duplex lines might be used with some increase of thruput. It could communicate in Transcode (a 6-bit code), 8-bit EBCDIC, or 7-bit ASCII.

The card reader/punch unit, similar to an IBM 1442, could read up to 400 cards per minute(cpm) and punch up to 355 cpm. The 2780 line printer was similar to the IBM 1443 and could print up to 240 lines per minute (lpm), or 300 using an extremely restricted character set. The 2780 was capable of local (offline) card to print operation.

The IBM 3780, an enhanced version of the 2780, was announced in May 1972. The 3780 was developed by IBM's Data Processing Division (DPD).

The 3780 dropped Transcode support and incorporated several performance enhancements. It supported compression of blank fields in data using Run-length encoding. It provided the ability to interleave data between devices, introduced double buffering, and added support for the Wait-before-transmit ACKnowledgement (WACK) and Temporary Text Delay (TTD) Binary Synchronous control characters.

...
Wikipedia