Buzz
When a PC needs to send data to a printer, it transmits it via a parallel port, serial port, or a network connection.
In the case of a parallel port, the computer transfers data one byte at a time (8 bits in parallel, unlike 8 bits transferred serially through a serial port). For each byte, it sends a handshaking signal to allow the printer to latch the byte.
To receive data through a parallel port, all you need is an 8-bit latch along with some simple glue logic.
Here are some useful links to explore:
- Understanding How Parallel Ports Operate
- Exploring How USB Ports Function
- Explaining How Serial Ports Work
- Connecting the IBM PC Parallel Printer Port
- ePanorama's PC Hardware Information Page
