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 varies. -- Eric Christopherson
