The Atari 1020 printer / plotter is an excellent Atari product as shown by Tom Hudson’s Solid States in ANALOG Computing, issue 16.

To an aspiring young programmer, the plotter is a marvelous drawing tool. However, unless one knows a little trigonometry, it can be difficult to produce those intriguing circular patterns create by such languages as Logo and Pilot.

The turtle interpreter
Turtle 1020 is an interpreted language written in Atari BASIC. The interpreter is a mixture of Pilot, Logo and BASIC commands-TURN from Pilot, FORWARD from Logo and variable use as in BASIC.

The editor
Turtle 1020 uses the standard Atari editor, in that you can edit a line by cursoring up and over to the desired line. All the usual INSERT and DELETE functions still work, except each turtle line is limited to 40 characters in length. The editor assumes that any command without a line number is an immediate command and that those preceded by a line number from 1 to 199 are program lines.

PDF

Leigh, J., Turtle 1020, Analog Computing, vol 35, pp. 88-96, October 1st, 1985.