Ten Games, Day 2
2020-04-25 17:29:14.608893+02 by Dan Lyke 0 comments
Day 2 of the 10 Video Games that were influential in your life (or however it was phrased) challenge. The playing along was super fun on day 1, love to see more!
Gotta pick a side scroller, and Choplifter is one, if only because it was also one that subverted the "shoot everything that moved" paradigm. My dad bought some sort of surplus European Apple ][+ board, and a family friend, Les Polgar did similarly, with the intent of altering them to work with NTSC rather than PAL video. In practice this meant that when they got together to work on this project, Les would bring a sherry, and they'd sit and sip and chat while I re-soldered the components to make them work with NTSC rather than PAL.
So the computer came together in a plywood case, with Shugart 40 track floppy drives (we could read disks written with Apple floppies, but could get a few more K of storage by poking a location in DOS and write those extra 5 tracks, even though other people couldn't use them).
When it came to coming up with a joystick, I hit up Radio Shack. I didn't have a good understanding of how pull-up resistors worked, so rather than a pull-up resistor with a normally-open switch, I used a normally-closed switch and tied it to Vcc, depending on the internal resistance to function as a pull- down (because this is what worked when I was poking wires into the I/O port). This was great for some things, but tends to be super electrically noisy on polled I/O, and however Choplifter did its I/O polling meant that it didn't register button presses.
So I played a (pirated) version of that game for quite a while before I discovered that, whoah, there was more to the game than luring the tanks away from the refugees, then landing and picking up the refugees, but you could actually shoot the tanks.
Mind. Blown.
I also discovered pull-up resistors.
I did, a few years ago, run into Dan Gorlin, the author of Choplifter, out in Lagunitas.