Subj : Re: USR 5686 no reply at AT command
To   : Digital Man
From : rmurray
Date : Thu Aug 22 2024 12:46 pm

 DM> Check the DIP switches on the modem. I seem to recall one of them (or
 DM> some combination) disables AT command support.
 DM> 

My config is 3, 5 and 8 at on.

 DM> Or it could be your serial cable or serial port at fault.
 DM>                                             digital man (rob)

And for my cable.  I checked on many sites and I checked again.  And the configuration that they tell me is this.

 DB9    Color      Signal Name                    DB25
  1      White      DCD (Data Carrier Detect)      8
  2      Blue       RXD (Receive Data)             3
  3      Green      TXD (Transmit Data)            2
  4      Orange     DTR (Data Terminal Ready)      20
  5      Black      GND (Signal Ground)            7
  6      Brown      DSR (Data Set Ready)           6
  7      Yellow     RTS (Request to Send)          4
  8      Purple     CTS (Clear to Send)            5
  9      Red        RI  (Ring Indicator)           22

It's that???

                VA2RFC BBS    Les M‚chins, Qu‚bec  Canada
               SysOp: rmurray    PhoneNet: 1000040 (Modem)
  Telnet: va2rfcbbs.photorm.net:23    FsxNet: 21:1/235    FidoNet: 1:229/114

--- Mystic BBS v1.12 A48 (Windows/64)
 * Origin: VA2RFC BBS (21:1/235)

.