[HECnet] SC-40

[Johnny Billquist]

On 2015-02-13 14:44, Paul_Koning at Dell.com wrote:
Yes, but that   s 8 bits total.   I was referring to 7 bits, no parity, no fixed extra bit like a mark bit.

Right. And as to the question about no devices actually ever using 7 bits, it is still a good thing to test, when you are trying to find patterns. But I don't actually know of any device that actually have been 7 bits pure. But it is one way of testing for possible strange parity issues.

We can go on discussing possible ways of troubleshooting serial ports for quite a while. And I'm happy to do so, if we really want to.

But in the current case, the problem seems to indeed have been grounding problems. So from that point of view, this isn't a problem any more.

	Johnny


	paul

On Feb 12, 2015, at 9:45 PM, pechter at gmail.com wrote:

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:

...
Start with just 7 bits no parity. Try both one and two stop bits. Then move on from there.

7 bits no parity is something I   ve never seen.   I would start with 8 bits no parity, one stop bit unless it   s 110 bps.   7 bits with parity, that does come up on a few occasions.   But while I   ve seen 8 and 5 and even 6 bit serial comms used, I can   t think of any 7 bits in the wild.

	paul


-- 
Johnny Billquist                                   || "I'm on a bus
                                                                  ||   on a psychedelic trip
email: bqt at softjar.se                         ||   Reading murder books
pdp is alive!                                         ||   tryin' to stay hip" - B. Idol