Hello everybody, I'm currently taking Electrical Engineering as senior physics major at Fordham University and have decided to take on a little side project to gain a better understanding. What I'm attempting to create is my own Transistor Logic -> RS-232 (Rs-232 refers to the serial (com1) port on computers). I found a perfect simple circuit schematic which I've attached below, and I've purchased the breadboard, soldering iron and all the exact resistors, capacitors and diodes required. My problem is I couldn't find the two transistors, NPN BC548 and PNP BC559 at any of my nearby Radio Shacks. After comparing the spec sheets online and doing a little bit of googling, I found that PNP transistor 2N3906's characteristics and specs seem to fit pretty well with BC559 and BC548 fits fairly well with 2N3904's. Unfortunately, we've only just got into transistors in EE right now and I have no equations to simplify them and determine if the voltage will be operable or even destructive for the computer that will be receiving the signal and sending it back. Below is a fairly comprehensive diagram for the circuit that I retrieved from a website. My alterations, as I said, will be subbing in the 2N3906 for the BC559 and the 2N3904 for the BC548. What will this mean for my final voltages?