I found the materials referenced earlier, a 1988 NASA paper explaining the theory and Sinclair BASIC code implementation to perform certain satellite orbit calculations.

Here's the paper as PDF
https://ntrs.nasa.gov/citations/19890004681
NASA Technical Paper 2811
An Economical Semi Analytical Orbit Theory for Micro-Computer Applications

The header of the code reads:

See a scan with some of the intricate Sinclair BASIC code in the images below.

#TimexSinclair #ZXSpectrum #Spectrum #Speccy #retrocomputing #TS2068 #NASA #space

NASA Technical Paper 2811

March 1988

An Economical Semi Analytical Orbit Theory for Micro-Computer Applications

UPDATE: PDF at the NASA documentation site found here:
https://oldbytes.space/@haitchfive/115245382670312540

Folks at the Timex Sinclair Online Group are doing some restoration work trying to help re-create 1980s NASA satellite orbit calculation code written for Timex Sinclair computers, up until now only existing in vanishing printed form.

https://www.youtube.com/watch?v=dpOQqbfj2Ao

#TimexSinclair #ZXSpectrum #Spectrum #Speccy #retrocomputing #nasa #space #TS2068

Here's some more detail about the recently revived Timex Computer 3256 (a third-generation ZX Spectrum successor derived from the Timex Sinclair 2068 and the Timex Computer 2048)
https://loadzx.com/timexcomputerworld/tc3256/

#ZXSpectrum #Speccy #Spectrum #TS2068 #TC2048 #Timex #TimexComputer #TC3256 #TimexComputer3256 #TimexSinclair #retrocomputing

Few of us, even the most studious ones, probably ever heard of the Timex Computer 3256, a ZX Spectrum-inspired successor to the Timex Sinclair 2068, or believed it was forever lost to time.

Some incredible engineers unearthed the Timex Computer 3256 AND its peripherals, and revived it in 2024. The Sinclair-inspired computer, its networking interface called TENET (short for: Timex Educational Network), floppy drive controller, networking software for the classroom, and all. Restored, revived, and re-created in new hardware. It's nothing short of a Jurassic Park achievement, infusing life and embodiment to something that only remained in some faint ROM memories.

See their presentation here:
"TENET: A deep dive into the lost ZX Spectrum Network"
https://www.youtube.com/watch?v=Mkn9syUI_N8
(it's a long one, but I promise every minute is worth it for the dedicated ZX Spectrum engineer)

#Timex #TimexSinclair #ZXSpectrum #Speccy #Spectrum #retrocomputing #TC3256 #TS2068

The Timex Computer 3256 was the right idea, with the wrong business people, a couple of years too late.

#TimexSinclair #ZXSpectrum #Spectrum #Speccy #retrocomputing #Timex