Adafruit visited the history of the LOGO “turtle graphics” language not long ago.

Now on Twitter, folks have found the source code for the MIT LOGO program used on Apple II computers, later licensed to Terrapin. Source on GitHub.

It turns out that the program was written on a big iron Digital Equipment Corporation (DEC) PDP-10 mainframe running the Incompatible Timesharing System (ITS). The code is dated September 4th, 1980.

Lars Brinkhoff‏ found it and posted the discovery on Twitter. He received permission from the authors to post the code.

The code is in 6502 assembly and the program works the whole Apple II memory map for functionality. The code was built by a cross assembler which came from the DECUS user group and originally ran on the DEC’s proprietary TOPS-10 operating system. It runs on ITS by way of a TOPS-10 system call emulator.

Very interesting programming archaeology – see the source code yourself along with the full PDP-10 ITS image still maintained today.

LSCI Logo, another LOGO implementation, was also licensed to Apple and is different from MIT’s LOGO.

** Updated with some info from Mr. Brinkhoff – thank you! **