[Coco] serial port problem

[Gene Heskett]

On Friday 01 November 2013 08:55:49 Mathieu Bouchard did opine:

> Le 2013-10-31 à 21:45:00, Tormod Volden a écrit :
> > I would have my doubts about UltimaTerm, especially after reading
> > Aaron's reply. Or the PC side - have you tested higher speeds with
> > something else than the CoCo, for instance loopback by shorting RX and
> > TX on the RS232 plug? You could of course try loopback on the CoCo
> > side as well.
> 
> using a piece of paperclip between pin 2 and 3 at the other end of the
> DB9-to-DB9 cable allows me to climb up to 115200 bps in Terminate (PC),
> at least when typing some characters on the keyboard.
> 
> Plugging a piece of paperclip directly into the CoCo3's serial port, I
> can get up to 19200 in UltimaTerm (the maximum).
> 
> Using a combination of CoCo3 + DIN4-to-DB9 adaptor (custom-made) +
> DB9-to-DB9 cable + paperclip (instead of PC), I can also transmit at
> 19200 in UltimaTerm.
> 
> So, the problem is that the CoCo3 and the PC don't like each other... I
> don't have the means to verify the quality of the signal going across
> the wires of my adaptor or the cable, but it's a problem that happens
> only using a combination of the PC with the CoCo.
> 
> I can't try between two different PCs at the moment, nor two different
> CoCos. I don't know whether trying this would help.
> 
> > it would be strange that the result is so binary as you experience.
> 
> I narrowed it down even more : I said it worked at 2400 and failed
> completely at 4800, and now I say it fails completely at 3600 too...
> 
>   ______________________________________________________________________
> 
> | Mathieu BOUCHARD ----- téléphone : +1.514.383.3801 ----- Montréal, QC

What I have done here, because the distance from the coco to the PC is many 
feet, is to use a 3' piece of cable from the coco, wired as per the link in 
a previous message this morning, to a seriel to usb adaptor plugged into a 
7 port powered usb hub.  That hub also feeds a Brother HL2140 B&W laser 
printer.  From that hub, a 10 meter usb extension cable cable comes up to a 
powered usb hub near the PC, and that hub in turn is plugged into a 
breakout connector on the PC.

The drivewire.jar is configured to use (this is linux of course) 
/dev/ttyUSB1 (could also be 0 but my ups uses 0)

This works flawlessly.  And since my nitros9 bootfile has the dw version of 
the /p driver and descriptor in it, what I send to /p when working on code, 
comes up the cable to the drivewire server and gets written to a file.  
Some scripts I wrote detect the closing of that file, pick it up and move 
it to get it out of the way, then send it back to the HL2140 printer by way 
of rendering it to what the printer understands in cups, the Common Unix 
Printing System.  So I get my assembly language listings, printed far 
prettier than any other printer I ever used on the coco, at 19 pages a 
minute.  Cups, BTW, was written by Michael Sweet, who some of you may 
remember as dodgecolt when the list was on delphi. Possibly on 
Princeton.edu too.

Now, I need to go put our local AM radio station back on the air if I can.
Old transmitter, 59 model, needs old engineer, '34 model.  At least thats 
the excuse we use...

Cheers, Gene
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)

Oh yeah?  Well, I remember when sex was dirty and the air was clean.
A pen in the hand of this president is far more
dangerous than 200 million guns in the hands of
         law-abiding citizens.