serial driver for full 3.3v uC to back-of-computer
If you wish to use all eight signals, you can use MAX3243E. It is quite similar to MAX232 but it gives you 5 receivers (CD, RXD, DSR, CTS, RI) and 3 drivers (TXD, DTR, RTS).


RXD and TXD are data.
DSR, CTS, DTR and RTS are for flow control.
CD and RI are just indicators and generally almost never used (except for modems).