laptop and comm ports...

[P.V.]

have a compaq (new) that has no serial port on the back (why the heck not??) but does have usb ports, two on the left side and one on the right. I need to connect an adapter so I can use a serial port item via the usb port. Bought the adapter for $15.00 install'd the driver and now find that it installed/open'd?? the "comm port5". Now, in looking, I see that there could be as many as 20 or 30 comm ports, Huh?? If I want to be able to plug the usb adapter into the rearward left usb port, which "comm port" should be active?? 1,2,3,4,5,..17,24..?? Confusing to me.. Someone said 5 but..... which one would be the forward left side, how about the one on the right?? Any help would be appreciated! Thanks!

 

[Xcusme]

Re: laptop and comm ports...

You said the driver is installed and now you have a Com Port 5. That's the port that will communicate thru the adaptor. The adaptor is now comm port 5.<br />The first 4 comm ports (serial) are reserved within your OS. <br />Normally the serial comm ports are numbered AND have a port address and irq as follows:<br /><br />Com1 3F8 irq 4<br />Com2 2F8 irq 3<br />Com3 3E8 irq 4<br />Com4 2E8 irq 3<br />You might want to goto Hardware Manager and have a peek at the details for Com port 5. Be mindful of not only the port address but the irq as well. If your com 5 port is sharing an irq with say your video card or hard drive, both devices will have to share the interrupt (irq)and you could experience performance issues between the two devices.Some software will not allow you to define another comm port beyond com 1-4. In this case a small comm port utility will disable one of the normal com ports on your system , and then your adaptor can use that 'open slot'. Your mileage may vary and the software will 'see' the extra com 5 with no problems.

 

[P.V.]

Re: laptop and comm ports...

X, Thanks for the reply. One additional query. So does it matter which usb port I install the adapter or is it just that I must restart the laptop with it already plugg'd in?? Again, thanks! P.V.

 

[Xcusme]

Re: laptop and comm ports...

Nope , it shouldn't matter what USB port you plug into. Since the drivers are in place, just plug in the adaptor, the driver should link the serial I/O signals thru the USB port and you're good to go. My GPS adaptor is USB with the drivers to 'talk' to the system as if it were a direct serial port. It shows an additional "Com Port". The USB drivers do the translation.

 

[P.V.]

Re: laptop and comm ports...

Thanks again!!

 

[Peter J Fraser]

Re: laptop and comm ports...

I bought a new laptop just before christmas. One of the requirements was for a Serial port. our supplier / tech's had quite a lot of difficulty in sourcing but finally I got a new NEC with a serial port.<br />I have a few applications which require a serial port for comms and have tried using USB / Serial replicators in the past but they are unreliable to say the least.<br />Now? no more problems using the serial connex.<br />I'm happy.<br /><br />Peter

 

[Bob_VT]

Re: laptop and comm ports...

I use a Belkin adapter on my laptop for my GPS it was a pain to figure out the port but it works fine.<br /><br />bob