On Thu, 7 Sep 2006, L. V. Lammert wrote:

> On Thu, 7 Sep 2006, Woodchuck wrote:
> 
> > On Wed, 6 Sep 2006, Edd Barrett wrote:
> >
> >
> > > If it works with the sun box, I assumed it's the correct cable?
> >
> > Not necessarily the case, said the grey old admin, sighing and
> > wincing with the facial tic he thought he had lost in the mid 1990's.
> >
> Nah, .. forget the documentation! Save the gray cells and get yourself an

THe documentation for these terminals are often full of lies and wishes.
Perusing the source for terminfo/termcap will convince anyone of that.
Each line in there is written with blood, sweat and tears.

> 'RS232 breakout box'. Most electronic stores have them, as do most network
> vendors. Most PCs use DB9s, but if you can't find a breakout box with DB9s
> you can also get 25->9 adapters (just be sure to get the right 'sex').
> 
> A breakout box will show if the data leads are crossed - you need to see
> 'lights' on 2 AND 3 (TX & RX) to know your connection is correct. If
> not, just swap 2 and 3. MOST terminals will run quite happily with 2, 3,
> and gnd (5 or 7).

Unless you do smooth scroll on a VT-xxx and aren't using software
(XON-XOFF) flow control.  Old terminals have very small data buffers.

If the terminal will handle a curses app like top(1) at 9600, it's
probably set up OK.  19200 baud is the proof of the pudding.

> Knowing what is actually happening is a lot nicer than just trying one
> cable after another.

It sure is, but it's still painful.

> 
>       Lee

Breakout boxes... shudder... line analyzers... shudder and flinch.

I used to do this with an Ohmmeter with a paperclip soldered to each
lead.  Sometimes I'd bribe a hardware guy with doughnuts to use his
oscilloscope.

Dave
-- 
Experience runs an expensive school, but fools will learn in no other.
                       -- Benjamin Franklin

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