vt100 terminfo with padding for an actual vt100?

Eric Christopherson echristopherson at gmail.com
Tue Sep 6 18:18:21 CDT 2016

On Tue, Sep 06, 2016, Paul Koning wrote:
> 19200?  I didn't think the VT100 supported that.
> You've got to be careful with that setting, even on devices that claim
> to do it.  When it first appeared, it was often a "just barely
> possible" setting on the clock generator, with an actual bit rate off
> a couple of percent from the correct value.  If both ends used the
> same clock generators, no problem of course.  But if one end uses an
> accurate one, you may get framing errors.

Is this why modems went to 14400 instead of 19200?

> On the other hand, flow control issues do not result in "garbage"
> characters.  The only way you'd get what looks like garbage is if
> escape sequences are corrupted so a portion of that sequence is
> mistaken for text.  If you see garbage in a full screen editor, that
> could be the reason.  On the other hand, if you're just sending a
> large document to the screen and you're seeing garbage, flow control
> is not the cause.

Interesting. I've been trying to get a WiFi device for the Commodore
8-bits working consistently in 9600 bps mode, and have just been
assuming the garbage characters I get when I receive a screenful of text
all at once were due to buffer overruns. The garbage characters there
look like actual garbage, not like partial CSIs like [3;1m or whatever.

> Earlier on there was some discussion about modern interface devices
> with non-compliant "RS232" transceivers.  If your RS232 output is
> marginal, that could cause garbage.  If the clocks are off, ditto.  An
> oscilloscope could be used to test both those theories.

I wonder if it's a similar sort of timing issue between my device and
the computer. I'll have to try a few computers and see if behavior

-- Eric Christopherson

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