It was written in 6502 assembly language for the Apple II.
It had a really nice display:
- 2 boats, with oars moving timed to your pulls - scrolling scenery - stroke power graphs - odometers that rolled over like mechanical odometers.
I had a piece of tinfoil taped to the wheel on the concept II. There was an aluminum box divided in two with a flashlight bulb on one side and a photocell on the other. When the tinfoil passed under the alumium box the photocell resistance would change, which would be available to the program via a wirewrapped expansion board (that also gave the Apple II 60hz interrupts - a native Apple II has no timer or interrupt controller). I later saw a Cateye magnetic bicyle wheel sensor and felt like such an idiot.
It also had an integrated breakout game that was controlled by the difference in power between the two rowers. Because of how one wrote games in that day (often directly using screen memory as data), if the ball ever escaped the brickout playfield it would start colliding with (and corrupting) other things on the screen, and if it ever left the screen, with random bits of executable code.
When you got a high score on a 20 min row, I had an army surplus air raid siren that would spin up. The idea was that after you completely killed youself on the erg, you would then have to run like crazy to avoid getting deafened by an air raid siren in a small room (thankfully this last part never worked well). A very high school idea.