vt100 terminfo with padding for an actual vt100?

Adrian Graham witchy at binarydinosaurs.co.uk
Mon Sep 5 02:24:06 CDT 2016

On 05/09/2016 01:10, "Fritz Mueller" <fritzm at fritzm.org> wrote:

> Hi all ‹
> I¹m trying to run a real-deal vt100 on a serial port connected to Linux
> (Xubunto 16.04).  I¹ve got this working *pretty* well, but it looks like the
> padding values in the default vt100 terminfo entry are not quite correct ‹
> when running the vt100 at 9600 I still get occasional garbage characters on
> the screen, and 19200 is a hopeless mess.
> I did figure out that if the terminfo contains ³xon², the non-mandatory
> padding values in the terminfo are disregarded.  Removing this, then disabling
> xon/xoff on both the vt100 and the tty device actually produces *better*
> results ‹ apparently the turnaround on xon/xoff isn¹t quite fast enough to
> keep the terminal from being swamped at higher baud rates, and padding
> actually works better.  But tracking down the source for the default vt100
> entry turned up a comment that admits that the padding values there are a
> total guess. :-( 
> So, before I go diving too much further into the terminfo-tweaking-samp, I
> thought I¹d ask if anybody has a good vt100 entry already on hand?  (I¹d take
> one for the VT52 as well!)

Interesting. I'm running a genuine VT100 from a home-made serial port
(MAX3232 based) on a Beaglebone Black running Debian Jessie as part of my
DECbox project and it's rock solid at 9600 baud, even with smooth scroll.
I'd never given the termcap entry a moment's thought.

This may or may not help, but when talking serially to a ZX Spectrum (I
know, but it's still RS232 comms) I get consistent results with a genuine
serial port on a laptop but with a cheap chinese USB-serial converter it
just doesn't work and I put this down to incorrect grounding.

Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer

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