Focal-65 V3D reconstruction, from listing for KIm-1 and TIM


Focal is a programming language originating from Digital Equipment, first on the PDP-8.
In 1977 Wayne Wall of the Denver 6502 Group programmed Focal-65 a port to the 6502, based upon the DEC manuals.
A small interpreter (about 5K) for a convenient interpreted language. Floating point 9 digit accuracy. At least two versions were distributed around 1977, one by Aresco, called “Focal V3D” and another by the Program Exchange as representative of the Denver 6502 Group, often called “Focal-65E”

I played with Focal-65 V3D on my KIM-1 in 1978, and preserved the binary and user manual.

In 2023 I finally was given a just readable scan of the listing that was an option of the Focal-65 pack
age. It is a version for the TIM (Jolt, Superjolt, 6530-004).

With it I made a reconstruction of the sources, , of Focal V3D for the TIM to binary, and a port to the KIM-1. Also the Aresco version source is reconstructed and identical to my tape dump of 1978.

Another piece of history preserved!

A page devoted to Focal-65 V3D with the sources here


As someone who has made similar reconstructions by typing in listings, I appreciate the work that went into this. Well done!


I ordered a used CS textbook via eBay from Ukraine. Lo and behold the coding examples are all written in Focal. The rest of the book is in Cyrillic. I don’t understand Russian, but it was fun to skim the examples. One can imagine a Soviet clone of a DEC computer was the target. Several PDP-11 compatible microprocessors were fabricated and incorporated into “PC like” computers, some for educational and home use.


The Saratov computers were soviet clones of the PDP-8. For a while the wall-ornament core memory you could get on ebay was from broken-up Saratovs. I’m sure they would have run Focal.

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