Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cwjcc!tut.cis.ohio-state.edu!rutgers!att!lzaz!hcj
From: hcj@lzaz.ATT.COM (HC Johnson)
Newsgroups: comp.os.minix
Subject: ST kernel with rs232 -- musings on login on tty1
Message-ID: <477@lzaz.ATT.COM>
Date: 17 Mar 89 14:43:01 GMT
Organization: AT&T ISL Lincroft NJ USA
Lines: 30


> Wim ten Have writes:
> to Login on /dev/tty1:
> a dumb terminal on tty1 needs CRMOD and XTABS
> speed on tty1 changes between 19200 , 2400, and my speed of 9600.

The problem of connecting a device to tty1 that is not itself a minix
ansi terminal is deaper than CRMOD and XTABS.  But I agree, there is
NO output processing in the rs232 driver.  A general fix is to
abandon the obsolete sgtty structures in the kernel and use termio.

The extension of /dev/tty1 to a general set of terminals is an interesting
exercise.


I would suspect that the speed changes arrise from the following.
a. 19200 is a speed of 0.  Someone is doing ioctl to 'stdin' that
   only sets the structure, not modify it.  (For example, 
   Login.c does this, thus
b. 2400 is the default speed I use, and so its in ttyinit().  I suggest
   that anyone planning to run at a known different speed, change this
   here.  It will show up if the port is opened and closed in the wrong
   order.  SH does many unnecessary open/close.  The ultimate fix is to
   train MINIX to know about 'final close', a UNIX(r) basic.
   the necessity of adding the setting of speed.).

Howard C. Johnson
ATT Bell Labs
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