combo board problems
Franco E. Barber
feb at cbnews.ATT.COM
Mon May 22 02:43:33 AEST 1989
In article <12185 at rcsuna.UUCP> rhaar at rcsuna.UUCP (Bob Haar CS50) writes:
>I am having a problem with a combo board and need to
>get some help.
>3) is the loop-back connecto that I made correct? It works for
> testing the standard serial port. The connections I made are:
> |-- pin 2 (Data transmit)
> |
> |-- pin 3 (Data receive)
> |-- pin 4 (Request to send)
> |
> |-- pin 5 (Clear to send)
> |
> |-- pin 8 (carrier detect)
> |-- pin 6 (Data set ready)
> |
> |-- pin 20 (Data terminal ready)
> |
> |-- pin 22 (Ring detect)
>Bob Haar
>G.M. Research Labs
>uunet!edsews!rphroy!rcsuna!rhaar
>HAAR at GMR.COM (CSNET)
That connector works only for the built-in serial port.
The loopback connector for the expansion ports has to cross
connect the two ports on the card. Ie, pin 2 on port 1 to pin 3 on
port 2, etc. The diagnostics even test the external clock inputs.
here are the appropriate connections:
port 1 port 2
TxD 2 ----- 3 RxD
RxD 3 ----- 2 TxD
RTS 4 ----- 5 CTS and 8 CD
CTS 5 and CD 8 ----- 4 RTS
DSR 6 and RI 22 ----- 20 DTR
DTR 20 ----- 6 DSR and 22 RI
TxClk 15 and RxClk 17 ----- 24 DTE TxClk
DTE TxClk 24 ----- 15 TxClk and 17 RxClk
GND 7 ----- 7 GND
Franco Barber
att!cblpe!feb
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