The IBMs 3210 and 3215 were printer-keyboards from the early 1970s. The 3210 and 3215 were auxiliary I/O terminals that provided two-way communication between an operator and an attached data processing system such as the aforementioned Model 145. The 3210 typing element was specifically based on the Selectric I/O-II2, however, the 3215 employed a unique typing element that could print significantly faster than the 3210. A known system both keyboards operated with was the IBM System/370 Model 145, a "high-availability general-purpose" data processing system from 19703.
The 3210 Model 1 is the table-mounted variant that has the capability of altering and displaying data in storage directly from the System/370 CPU.
The 3210 Model 2 is the pedestal mounted variant that connects to the System/370 CPU via an external signal cable and does not have the capability of altering and displaying data in storage directly from the System CPU.
The 3215 is similar to the 3210 Model 1 in that it's a table-mounted unit and both keyboards can accept the same I/O commands and functionality, however, the IBM 3215 can print approximately 85 characters a second versus just 15.5 for both 3210s thanks to its unique 7x7 dot matrix printing element. The 3215 is also invariably referred to as the 3215 Model 13 despite the absence of a 3215 with a different model number.