PC serial port connection

What is the significance of shorting together pins 1,6,4 and 7,8 while leaving pin 9 open and pin 5 grounded?

Normally i just connect the Tx and Rx pin and it seems ok. Is it really that important?

Spectacular Butter said:

What is the significance of shorting together pins 1,6,4 and 7,8 while leaving pin 9 open and pin 5 grounded?

Normally i just connect the Tx and Rx pin and it seems ok. Is it really that important?

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Without looking up the pin details, I presume they are the handshake lines, depending on the particular program it might require hardware handshaking - so you either need to provide handshaking, or copnnect them across to fool it.

So it's only important if hardware handshaking is required by the program!.

7 and 8

Several are handshaking pins. The only ones to really be concerned with are RTS (request to send) and CTS (clear to send). These are pins 7 and 8. In rare cases you may have trouble sending data from a computer with only pins 2,3, and 5 connected. This is usually because an RTS signal is unanswered. To solve this just connect pins 7 and 8 together. It is best to do this anyway just to be safe.