RS232 spec

Have you tried google? Like, for example:

Good Luck! Rich

Hi Paul,

If you're interested in designing a system that uses the 232 protocol, then I would suggest reading the data sheet of the 232 part you would like to use. Good place to get datasheets:

alldatasheet.com

If you want to implement your own 232 protocol, say with a microcontroller, you will still need the parts to transform the signals into correct voltage levels (5V to -10V etc). The protocol after that is simply the baud rate (typically 9600), the start bit, stop bits (typically 1), and parity which you can leave out for a simple design at low baud rate. Just remember to idle the 232 line high and the start bit will control the flow of data.

The RS-232 (EIA-232) spec is copyrighted material. EIA typically charges aroun $20- $30 per spec. However, useful information can be found at

Is there any particular reason why you want these older versions rather than the current one?

Regards, Allan