The Penman Robotic Turtle/Plotter is just as its name applies...a robotic plotting device that connects up to an RS-232 serial port. It consists of two pieces...the turtle, which has wells to hold 3 pens of various colours, plus a centre well for a black pen, and which crawls around on castors. The second part is the control unit which is connected to the computer's RS-232 port and which accepts movement commands from the computer as well as position data from the turtle. The two are connected by way of a ribbon cable which feeds out from a well in the control unit. The Penman dates from about 1985.

An interesting thing about the Penman is that unlike normal plotters where the paper is inserted into the plotter, in this instance the turtle is placed on top of the paper and it is the turtle that moves around, sensing when it has reached the paper's edge and sending and receiving data to/from the control unit. As with most early printers, the Penman may be controlled using commands from BASIC, though programming each movement could prove cumbersome. It would appear that there were a number of programs written which supported the turtle directly, though it would seem they were written by the same company.

This low-cost plotter printer, robot, turtle, mouse for use with any RS232/Rs423 compatible computer with Full Colour Plotting, Graphics & Text. Unfortunately we do not have the pen unit. Total price was £280.82 on the 3rd January 1985 with Grafpad & Pen

It was a side design from one of the Eurotherm Engineers and they were at one point, a subsidiary of Chessel (now called Eurotherm Chart Recorders).