Introduction to serial communications
I ran accross this just now and it takes me back a couple years. RS232C is a familiar sounding standard. I spent alot of time with signal generators and Oscilliscopes on those pins. I'm just glad I can't remember the stinking pinout!
Now what gets really narley is to see all the DS1's cabled into an ATM. Oh man, I can spend hours thinking about all the patch cords and multiplexors.