Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!rutgers!cmcl2!phri!marob!daveh
From: daveh@marob.MASA.COM (Dave Hammond)
Newsgroups: comp.unix.xenix
Subject: Re: serial port lockups (was 386 Xenix 2.3.1/vpix/Compaq 20 Problem)
Message-ID: <611@marob.MASA.COM>
Date: 10 Apr 89 12:44:06 GMT
References: <226@ecicrl.UUCP> <173@summus.UUCP>
Reply-To: daveh@marob.masa.com (Dave Hammond)
Organization: ESCC  New York City
Lines: 23

In article <226@ecicrl.UUCP>, clewis@ecicrl.UUCP (Chris Lewis) writes
of a problem where his system's terminal i/o hangs up continuously.

In article <173@summus.UUCP> craigp@summus.UUCP (craigp) suggests that
the length of the terminal serial lines may contribute to the problem,
especially on AST boards.

I have also seen serial i/o on long RS232 lines (the RS232 spec
provides for <= 50 ft. lines) cause lockups.  The MOST offensive board
was the AST "4-PXN", however, I have seen similar problems on Arnet
boards and Computone boards.

In the cases of the Arnet and Computone boards, a line-driver was installed
on the long lines [shortening lines is not very feasable when the client's desk
was in place well before the computer :-)], which solved all problems.

In the case of the AST board, the only cure was quick and sure decapitation
[of the AST].  It was replaced with an Arnet, with no significant problems
since.

--
Dave Hammond
daveh@marob.masa.com