[Coco] serial port problem

[Mathieu Bouchard]

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