First post, by popcalent
I'm trying to make a PC104 Game Card and I'm using a regular 8-bit ISA Game Card schematic for reference and an actual 8-bit ISA Game Card with a voltmeter for reference.
The schematics of the IBM manual, and what I found out with the voltmeter don't match. The last picture shows a table where the first column is the game port pinout, the second column is the connections shown in the IBM manual, the third column is the connections of port 1 of my card, and the fourth column is the connections of port 2 of my card.
For instance, pin 2 of the IBM port is connected to pin 2 of the 74244 and it's represented as 74244[2].
None of the two ports on my board matches the IBM port... Port 2 is almost the same as the IBM port, but has two buttons reversed, and X2 and Y2 coordinates reversed. So what is it? What's the correct thing?