Turbo Pascal navigational aids that saved my life in 1991.
Sextant.pas worked in Atari Portfolio pocket computer. I had crude self-coded maps (like Helsinki.map) and after measuring sun's angle with sextant, this program drew a line perpendicular to the sun. If you waited a bit, you could acquire another line. Where those lines crossed that is where you were on the map. With several measurements the errors evened out and you could be quite sure within kilometer or so.
This is also about the "Artificial Horizon"-issue I learned from TV:
I had $50 plastic sextant. I made a program in my pocket computer (Atari Portfolio) which automatically showed your position on a map. Realized however that sextant is useless if there is no horizon visible in direction of the sun. I needed "artificial horizon" but it was $1000. Too expensive. Then I saw the movie about Nansen crossing the Greenland. All he had was a bottle of mercury. He simply measured the angle between the sun and its reflection. I felt soo stupid.
Then I started paddling from Vancouver city to the west in 1991. I did not understand them tides. I did not know you can get pretabulated tables. I was paddling against tides most of the time. Somewhere between Kelsey Bay and Telegraph Cove there was 2 weeks period of fog and rain. I totally lost it. I was running out of food. I decided to turn back to Kelsey. But then the setting sun peaked out and I was able get my longitude. I was 3 kilometers from Telegraph cove. Paddling back would have been a suicide.
BTW. George Vancouver was also stuck for weeks at the same stretch of Johnstone Strait. The devilish tide current appeared to be totally random and followed none of the god-given rules and laws.
Looks like the OBS.BAT is the main starting point
Taulu.pas makes a table of hourly sun angle for a month. When printed, It is a simple navigational aid, which requires no computer. If the sun is lower than in the paper, you should head towards the sun and vice versa. (Interface in Finnish)
Me also has a video of this trip: https://youtu.be/3TMziykDR0s