26 Feb
2013
26 Feb
'13
6:45 p.m.
In article <CAMDAk4f81=gcUh_GV14mGhZoH1rGpLfZk74pQG=sjjpqJ-NS0g at mail.gmail.com>,
Earl Evans <earl at retrobits.com> writes:
The garbage always starts in exactly the same place in
the DIR listing.
After that, garbage characters (grey squares) become interspersed with the
good text.
Try setting your baud rate to 300 and see if it still happens.
If so, then you have a hardware problem.
If not, then it's as suspected elsewhere in this thread -- the
emulated machine is feeding the VT100 faster than it can accept the
data.
The VT100 doesn't need padd characters IIRC (VT05 and VT52 definitely
do), but it uses a signalling scheme to tell the host that it's
internal buffer is full. This signalling scheme can be either in the
hardware signalling (DTR/CTS) or it can be XON/XOFF (DC1/DC3) control
characters in the data stream.
Relevant manuals for VT100 are linked here:
<http://terminals.classiccmp.org/wiki/index.php/DEC_VT100>
Under Windows, the default settings of a com port are not set to use
any flow control. I was recently generating ESC sequence laden files
for my Tektronix 4205 terminal on my PC and sending them to the COM3:
port with "copy foo.dat com3:" and the Tek was losing data and
garbling commands until I configured both the terminal and the COM
port to use the same flow control signalling. Then everything worked
properly.
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