I saw 7 bit mark and 7 even back in my old Field Service days in the 80s... Bill -----Original Message----- From: Paul_Koning at Dell.com To: hecnet at Update.UU.SE Sent: Thu, 12 Feb 2015 20:59 Subject: Re: [HECnet] SC-40 On Feb 12, 2015, at 12:41 PM, Johnny Billquist <bqt at softjar.se> wrote: =20 ... Start with just 7 bits no parity. Try both one and two stop bits. Then mo= ve on from there. 7 bits no parity is something I=E2=80=99ve never seen. I would start with = 8 bits no parity, one stop bit unless it=E2=80=99s 110 bps. 7 bits with pa= rity, that does come up on a few occasions. But while I=E2=80=99ve seen 8 = and 5 and even 6 bit serial comms used, I can=E2=80=99t think of any 7 bits= in the wild. The SC40 expects a serial byte with values 0..127 (8 bits, MSB always =0) no parity one stop bit. --P