Thanks for your help so far, guys!
I am trying to figure out how the keyboard-part of this circuit works so I have been reading up a bit on how different transistors work, but I have a couple of questions.
When used as a switch the PNP transistor gets the current to flow from the emitter to the collector when current flows out of the base, right?
The way I see it VCC (5V) is connected through a resistor network "R13" (4.7k) and is then connected to the emitter of the transistors Q6...Q13 which in turn has the collector pins connected to GND. What it the use of this? Nothing happens after current passes through the transistor and out of the collector. It just goes to ground. It doesn't look like you use the current that passes through. Obviously I must be missing something.
The base pin of the transistors seem to be connected to a bunch of ICs if I understand the schematics correctly (ROM, CPU, 74HC245 Octal bus transceiver)
If you are not using the transistor as an amplifier or using the base as a switch to get current to pass from emitter to collector and use it afterwards then why not just pass the current directly to the ICs and keyboard connector right after it has passed through the resistor network?
Please help me understand what is going on here