<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Jul 24, 2020, at 3:15 PM, Clem Cole <<a href="mailto:clemc@ccc.com" class="">clemc@ccc.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div dir="ltr" class=""><div class="gmail_default" style="font-family:arial,helvetica,sans-serif"><br class=""></div></div><br class=""><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Jul 24, 2020 at 2:37 PM Paul Koning <<a href="mailto:paulkoning@comcast.net" target="_blank" class="">paulkoning@comcast.net</a>> wrote:<br class=""></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">The right answer would be a tweak to the console emulation in SIMH pdp11. </blockquote><div class=""><span class="gmail_default" style="font-family:arial,helvetica,sans-serif">Mumble... Paul - I'm not so sure. While DEC used MARK a lot, there were places that used EVEN parity a lot also on PDP-11's (Lord how, I hated 20 mA current loop ;-) at least by the time of widespread RS-232C interfaces it was glass ttys and usually a full 8-bit data path. 7-bit with odd/even is defined this way:</span></div><div class=""><br class=""></div><div class=""><table style="font-size:17.5px;background-color:rgb(248,249,250);color:rgb(32,33,34);margin:1em;border:1px solid rgb(162,169,177);border-collapse:collapse;font-family:sans-serif;text-align:center" class=""><tbody class=""><tr class=""><th rowspan="2" style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em;background-color:rgb(234,236,240);text-align:center" class=""> bits of data<br class=""></th><th rowspan="2" style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em;background-color:rgb(234,236,240);text-align:center" class="">(count of 1-bits)</th><th colspan="2" style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em;background-color:rgb(234,236,240);text-align:center" class="">8 bits including parity</th></tr><tr class=""><th style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em;background-color:rgb(234,236,240);text-align:center" class="">even</th><th style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em;background-color:rgb(234,236,240);text-align:center" class="">odd</th></tr><tr class=""><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class="">0000000</td><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class="">0</td><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class=""><b class="">0</b>0000000</td><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class=""><b class="">1</b>0000000</td></tr><tr class=""><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class="">1010001</td><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class="">3</td><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class=""><b class="">1</b>1010001</td><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class=""><b class="">0</b>1010001</td></tr><tr class=""><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class="">1101001</td><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class="">4</td><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class=""><b class="">0</b>1101001</td><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class=""><b class="">1</b>1101001</td></tr><tr class=""><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class="">1111111</td><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class="">7</td><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class=""><b class="">1</b>1111111</td><td style="border:1px solid rgb(162,169,177);padding:0.2em 0.4em" class=""><b class="">0</b>1111111</td></tr></tbody></table><span class="gmail_default" style="font-family:arial,helvetica,sans-serif">FWIW: I'm on a Mac and I run a program called 'Serial' that can do that; but I thought most of the programs that simulate a serial connection for the different PC/Windows system have similar options. Certainly that was true when I did it with DOS.</span><br class=""></div></div></div></div></blockquote><div><br class=""></div>I use minicom, and yes, it can do all those things. But that wasn't the case I was thinking about. I thought the issue isn't so much the case where you have a terminal emulator program talking to a serial port, but rather the case of your command window in which you invoke simh (pdp11) and you're then talking to the console terminal. I would rather not have to change the settings on my regular shell to deal with oddball stuff expected by some application, I figure that's the application's job.</div><div><br class=""><blockquote type="cite" class=""><div class=""><div dir="ltr" class=""><div class="gmail_quote"><div class=""><span class="gmail_default" style="font-family:arial,helvetica,sans-serif"><div class=""><span class="gmail_default">Anyway, I think the 'right' answer for simh is to ask the user to use a serial emulation program that can generate any of: 8-bit no parity, 7-bit no parity, or 7-bits of data plus an 8th parity bit with any of the 4 parity options: odd, even, mark (aways 1) or space (always 0).</span> <span class="gmail_default"> Seems to me, simh should bring 8 bits into the simulated serial port and let the SW running on the system decide what it's going to do with it.</span></div><div class=""><span class="gmail_default"><br class=""></span></div><div class=""><span class="gmail_default">I'm curious to hear what Bob thinks? </span></div><div class=""></div></span></div></div></div>
</div></blockquote></div><br class=""><div class="">Parity is something that comes in addition to the data. DEC UARTS (and many others, I think) would let you set the data length (5, 6, 7, 8 bits) and the parity setting (none, even, odd). So what you called "8 bits including parity" is technically "7 bits with parity". If you set your UART for 8 bits with parity, it would send 11 bits total: start, 8 data, parity, stop.</div><div class=""><br class=""></div><div class="">I've even run into 10-bit UARTs (on PLATO terminals). But that's not DEC stuff.</div><div class=""><br class=""></div><div class=""><span class="Apple-tab-span" style="white-space:pre"> </span>paul</div><div class=""><br class=""></div></body></html>