27 Feb
2013
27 Feb
'13
12:51 p.m.
In article <CAMDAk4cMo1Dbb9GPw=6L0KV07AL0yFJxf5HnraTjcxMhJUGnhQ at mail.gmail.com>,
Earl Evans <earl at retrobits.com> writes:
Regarding the comments on baud rate and flow control -
still doesn't make
sense to me why the VT100 would not exhibit the error with a real PDP-11
(at 9600 baud), but does do it with the emulated PDP-11. The info is coming
at the terminal at the same rate - why would the behavior be different?
A real PDP-11 has hardware flow control turned on in the interface.
If you're coming in over a modem, you need to make sure both ends of
the communication are either i) setup for XON/XOFF flow control, or
ii) the remote OS is setup to use fill padding based on baud rate.
Escape sequence specifications in terminfo have the ability to specify
fill characters (or delays) based on baud rate. Here is my shell's
idea of the vt100 terminfo entry:
# Reconstructed via infocmp from file: /lib/terminfo/v/vt100
vt100|vt100-am|dec vt100 (w/advanced video),
am, mc5i, msgr, xenl, xon,
cols#80, it#8, lines#24, vt#3,
acsc=``aaffggjjkkllmmnnooppqqrrssttuuvvwwxxyyzz{{||}}~~,
bel=^G, blink=\E[5m$<2>, bold=\E[1m$<2>,
clear=\E[H\E[J$<50>, cr=^M, csr=\E[%i%p1%d;%p2%dr,
cub=\E[%p1%dD, cub1=^H, cud=\E[%p1%dB, cud1=^J,
cuf=\E[%p1%dC, cuf1=\E[C$<2>,
cup=\E[%i%p1%d;%p2%dH$<5>, cuu=\E[%p1%dA,
cuu1=\E[A$<2>, ed=\E[J$<50>, el=\E[K$<3>, el1=\E[1K$<3>,
enacs=\E(B\E)0, home=\E[H, ht=^I, hts=\EH, ind=^J, ka1=\EOq,
ka3=\EOs, kb2=\EOr, kbs=^H, kc1=\EOp, kc3=\EOn, kcub1=\EOD,
kcud1=\EOB, kcuf1=\EOC, kcuu1=\EOA, kent=\EOM, kf0=\EOy,
kf1=\EOP, kf10=\EOx, kf2=\EOQ, kf3=\EOR, kf4=\EOS, kf5=\EOt,
kf6=\EOu, kf7=\EOv, kf8=\EOl, kf9=\EOw, lf1=pf1, lf2=pf2,
lf3=pf3, lf4=pf4, mc0=\E[0i, mc4=\E[4i, mc5=\E[5i, rc=\E8,
rev=\E[7m$<2>, ri=\EM$<5>, rmacs=^O, rmam=\E[?7l,
rmkx=\E[?1l\E>, rmso=\E[m$<2>, rmul=\E[m$<2>,
rs2=\E>\E[?3l\E[?4l\E[?5l\E[?7h\E[?8h, sc=\E7,
sgr=\E[0%?%p1%p6%|%t;1%;%?%p2%t;4%;%?%p1%p3%|%t;7%;%?%p4%t;5%;m%?%p9%t\016%e\017%;$<2>,
sgr0=\E[m\017$<2>, smacs=^N, smam=\E[?7h, smkx=\E[?1h\E=,
smso=\E[7m$<2>, smul=\E[4m$<2>, tbc=\E[3g,
Notice the entries with <2>, <3>, etc. These specify the relative
delay or padding necessary when that ESC sequence is issued. The
delays are all proportional to baud rate -- the faster you
communicate, the more delay/padding is used.
--
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