Conversational Programming System
CPS was what was called a Type III program, one that was written by an IBM employee in the field and was unsupported. The quote below is from the Program Contribution Form for IBM program 360D-03.4.016 dated August 7, 1969. This document can be found in my office along with the CPS Terminal User's Manual, Installation and Administration Guide, and System Programmer's Guide.
"Conversational Programming System is a time-sharing system that runs in a partition of OS/360 Release 17 MFT II or MVT. The CPS language is a conversational dialect of PL/I and includes a modified subset of the BASIC language of IBM CALL/360. The system also provides Remote Job Entry to batch processing and Remote Job Output to a designated terminal from a dataset designated by any batch job." (This was hot stuff!)
"Prior to installation of Conversational Programming System, minor changes must be made to OS/360 and a new system generated. The system supports Models 40, 50, 65, 75, and 67 Model 1 in 65 mode, and Model 91, along with terminal types 2741 and 1052 as well as Teletype ASR Models 33 and 35." (That's what we used. Stored the programs on punch tape.)
"Minimum core requirements are for an H memory to support two terminals and a 64K background. Additional core (which may be 2361) of 18K bytes per active terminal is required for more than two terminals."