Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!ICAEN.UIOWA.EDU!dbfunk
From: dbfunk@ICAEN.UIOWA.EDU (David B Funk)
Newsgroups: comp.sys.apollo
Subject: Re: vt100, emt carriage return/linefeed problems
Message-ID: <8906160257.AA00404@icaen.uiowa.edu>
Date: 16 Jun 89 02:47:47 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: Iowa Computer Aided Engineering Network, University of Iowa
Lines: 36

Refering to article <12196@well.UUCP>
>In article <8906131338.AA03287@umix.cc.umich.edu> FERGUSON@TMASL.EXXON.COM writes:
>>
>>I want to use vt100 and emt to log into a vax, and other machines. When
>>I do, I can't for the life of me get linefeeds converted into CRLF's.
>
>I had the same problem, but it went away on sr10.1, if thats any 
>help.       I also had problems logging into a vax from 9.7 vt100
>and doing a  dir   or anything that generated a long list on the
>console... the apollo would lose data, not responding in time to the
>XOFF and overrunning the buffer.   All this seems to have cleared up
>when I upgraded to 10.1.   WHo knows what really is going on?

At sr9.x, when using EMT with VT100 to use screen editors on
a remote host, invoke Vt100 first, then invoke EMT within Vt100,
and use EMT options:

    raw
    tctl noecho
    interm lf

The "magic" one is the "interm lf". It prevents emt from eating up the "CR"s
and turning them into "NL" characters. Vt100 needs to see the raw "CR"s to
do its thing correctly.

The problem with the emt input buffer overflowing seems to be some kind
of timing related problem with the Apollo serial line input handler.
Even with Xon/Xoff flow control enabled, if data comes in at 9600 or faster,
in continuous chunks larger than 256 characters, the input buffer overflows.
If you set the speed to 4800 baud, there is no overflow problem. The strange
thing is that the serial line handler that came with the SPE board seems to
do a better job. It will do Xon/Xoff flow control at 9600 baud with no
overflow problems, it will choke at 19200 though. This is the case at sr9.7,
I've not checked it out at sr10.1.

Dave Funk