The only material I had access to when building my Logo computer was Papert’s “Mindstorms” book, the August 1982 issue of Byte Magazine and (a little later) Abelson’s “Apple Logo” book.
I also had a photocopy of the appendix of the manual for some Canadian Logo that had all its keywords translated to Portuguese. Unfortunately each group in Brazil did its own translation with no consistency between them. José Valente had brought PDP-11 Logo from MIT in the 1970s to Unicamp (a university in the state of São Paulo) but I didn’t have any access to what they were doing. So my only information was about what Logo was like in the 1980s.
Unless you watch the short YouTube video, you might miss the fact that Logo programs written for the 2500 graphics terminal could give each turtle-drawn vector a rotational velocity. My favorite demo makes it clear why Fourier transforms are powerful. (sorry, I don’t have a link)
Thanks for the code. It seems to have enough details for a hardware implementation to be created from that. These days the vector display is the most complicated part, though two simple ADCs connected to an oscilloscope will do the job even if the resulting screen will be smaller than it should be.
The full schematics is a lot of fun. The simulator I am using (called “Digital” and written in Java) includes most of these components so it would be easy to reimplement the original design.
I wonder what the cost for these components would have been in 1983 when I was doing my Logo computer? Memory would have been way cheaper, so it might have even been a viable product then.
That’s cool. A few of the parts are a little obscure that I tracked down. The 2507 was some flip flops with a shared register enable input. There’s an AOI gate that probably isn’t made anymore (7464). Six-bit 3-state buffer chips. It was harder back in the day!
