the TECO buffer storage and reformed the macros as native PDP-10 code. As entering the real-time mode was by typing , this was known as control-R mode. At the same time, Rici Liknaitski added input-time macros (), which operated as the command string was read rather than when executed. Read-time macros made the TECO auxiliary text buffers, called Q-registers, more useful. Carl expanded the Q-register name space. With read-time macros, a large Q-register name space, and efficient buffer operations, the stage was set for binding each key to a macro. These edit macros evolved into Emacs. The VMS implementation has a long history - it began as TECO-8, implemented in PDP-8 assembly. This code was translated into PDP-11 assembly to produce TECO-11. TECO-11 was used in early versions of VAX/VMS in PDP-11 compatibility mode. It was later translated from PDP-11 assembly into VAX assembly to produce TECO32. TECO32 was then converted with the VEST and AEST binary translation utilities to make it compatible with OpenVMS on the Alpha and Itanium respectively. OS/8 MUNG command The OS/8 CCL MUNG command invoked TECO to read and execute the specified .TE TECO macro. Optional command line parameters gave added adaptability. As a programmer's tool During and shortly following the years of the punched card era, there were source programs that had begun as punched card-based. Comments were often a series of lines that included single marginal asterisks and top/bottom full lines of asterisks. Once the cards were transferred online, it was a chore to realign the marginal stars. TECO to the rescue... As a programming language The obscurity of the TECO programming language is described in the following quote from "Real Programmers Don't Use Pascal", a letter from Ed Post to Datamation, July 1983: According to Craig Finseth, author of The Craft of Text Editing, TECO has been described as a "write-only" language, implying that once a program is written in TECO, it is extremely difficult to comprehend what it did without appropriate documentation. Despite its syntax, the TECO command language was tremendously powerful, and clones are still available for MS-DOS and for Unix. TECO commands are characters (including control-characters), and the prompt is a single asterisk: * The escape key displays as a dollar sign, pressed once it delineates the end of a command requiring an argument and pressed twice initiates the execution of the entered commands: *$$ Example code Given a