[ale] OT - was - Connecting to r-pi

[DJ-Pfulio]

Any chance that someone would change the subject, so lurkers seeking help with
their raspberry pis don't get confused?


On 10/26/18 11:56 AM, Scott Plante via Ale wrote:
> Actually, lack of good flow control was what inspired me to really learn vi
> really well. I used to program all the time on a dumb terminal connected to a
> Unix box, and if you just held down an arrow key to get midway across the
> screen, the whole session would become jumbled and you'd have to refresh. So I
> learned all the obscure vi keys to move around the screen and file instead of
> arrow/page keys. Once internalized, it made me much more efficient even after I
> had a reliable terminal connection or full desktop.
> 
> Scott
> 
> --------------------------------------------------------------------------------
> *From: *"Jim Kinney" <jim.kinney at gmail.com>
> *To: *"Chris Fowler" <cfowler at outpostsentinel.com>, "Atlanta Linux Enthusiasts"
> <ale at ale.org>, "Chris Fowler via Ale" <ale at ale.org>, "Scott Plante"
> <splante at insightsys.com>
> *Sent: *Thursday, October 25, 2018 8:12:39 PM
> *Subject: *Re: [ale] Connecting to r-pi
> 
> Alcohol cures all flow control memories. I have no idea what you just said :-)
> 
> Had to calculate and test timings in early grad school. Signal propogation time
> in wire plus time in detection circuits plus time to trigger action on detection
> plus actual signal length, etc. Now add in the blasted data collection system
> was getting data from multiple sources with different timings, yeah. Fun stuff.
> 
> On October 25, 2018 6:26:55 PM EDT, Chris Fowler via Ale <ale at ale.org> wrote:
> 
> 
> 
>     --------------------------------------------------------------------------------
> 
>         *From: *"Scott Plante via Ale" <ale at ale.org>
>         *To: *"Alex Carver" <agcarver+ale at acarver.net>, "Atlanta Linux
>         Enthusiasts" <ale at ale.org>
>         *Sent: *Wednesday, October 24, 2018 4:03:34 PM
>         *Subject: *Re: [ale] Connecting to r-pi
> 
>         If you're inclined to believe Wikipedia, the early teletypes would
>         actually perform a carriage return to the left and line feed the paper
>         up one row on a LF, but the CR was necessary because of timing--it took
>         longer than the gap between characters to physically return the print
>         head so they added the CR to allow enough time. Apparently they
>         sometimes had to add NULs as well. Even some CRT terminals took too long
>         to scroll all the text up. Apparently they didn't have flow control back
>         then.
> 
>     Very small buffers.  Very small.  I had a similar problem automating Nortel
>     Merdian PBX over its console.  I wrapped up the expect send into a function
>     that put a pause between each character.  I basically automated the PBX and
>     had to also simulate a person typing in the commands.   If not, the PBX
>     missed characters I had sent.  If a T1/PRI failed the program would try to
>     bring up and check.  If it was still in alarm it would report the alarm and
>     create the ticket. 
> 
> 
>         I used to have a TRS-80 and a "Gorilla Banana" printer. I could never
>         get the flow control to work with it, and had to write a program to
>         print stuff. It would manually pause a fraction of a second after each
>         line before sending the next one to the port. Those were the days! ha ha
> 
>     I was hoping I would never hear about flow control and serial printers ever
>     again.  And here you are...
> 
>     XON/XOFF flow control is software and does have a tendancy to not work well
>     with small buffer serial printers.
> 
>     Hardware could be either DTS/DSR or CTS/RTS flow on the printer.   Using
>     that would have made it work better.  The problem is that you need to know
>     what flow the printer supports or you need to set the DIP switches to the
>     flow you want.
> 
>     My Okidata days are 20 years behind me. :)
> 
>