Path: utzoo!utgpu!cunews!bnrgate!brtph3!brchh104!brchs1!bnr.ca!rice.edu!sun-spots-request
From: convex!datri@uxc.cso.uiuc.edu (Anthony A. Datri)
Newsgroups: comp.sys.sun
Subject: Re: Reset command crashes the system
Keywords: Miscellaneous
Message-ID: <748@brchh104.bnr.ca>
Date: 10 Dec 90 23:43:22 GMT
Sender: news@brchh104.bnr.ca
Organization: Sun-Spots
Lines: 50
Approved: Sun-Spots@rice.edu
X-Refs:  Original: v9n396
X-Sun-Spots-Digest: Volume 9, Issue 397, message 16
X-Note: Submissions: sun-spots@rice.edu, Admin: sun-spots-request@rice.edu

>(or OpenWindows), instead of using "reset", one should check out "kbd_mode
>-a" to clear up the console.

kbd_mode -a will put the console into a normal state -- sometimes after
the (mit at least) X server shuts down, the console is in a strange state
where every key seems to be interpretted as a return.  I have xinit
aliased to

  unset autologout; /usr/bin/X11/xinit >& /tmp/xinit.out ; kbd_mode -a

The redirect helps in debugging screwy .xinitrc files.

>The byte to be configured is location 0x1f:
>	00 - monochrome monitor
>	10 - ttya
>	11 - ttyb
>	12 - color monitor and 3/60 plug-in color frame buffer
>	20 - P4 Color frame buffer

Hmmmmm.  I've run afoul of this before.  When one purchased a color 3/60,
you got a cpu board without the bwtwo circuitry on it, but spare boards
all have the bwtwo.  So, when you swap a color board with a spare, you end
up having two bwtwo's, and I've never quite figured out what effect that's
*supposed* to have.  I have a couple machines like this that experience
strange behavior (up to and including spontaneous reboot) when reading
*certain* images.

This location is "documented" in /usr/include/mon/eeprom.h, where one can
find all *kinds* of interesting things.  It says (4.1):

* 0x01f */     char    eed_console;    /* device to use for console */
#define EED_CONS_BW     0x00            /* use b&w monitor for console */
#define EED_CONS_TTYA   0x10            /* use tty A port for console */
#define EED_CONS_TTYB   0x11            /* use tty B port for console */
#define EED_CONS_COLOR  0x12            /* use color monitor for console */
#define EED_CONS_P4     0x20            /* use the P4 monitor for console */

Of course, it's not *really* clear from this file what "color" means.  I
think that the repaired machines I mentioned above perhaps had this set to
0, and things worked okay as long as the on-board bwtwo didn't exist, but
when one started existing, all I got was blackness on the real console.
Poking around blind in an eeprom is great fun8^).

>Get to the PROM monitor (for example, "shutdown -hf now").  At the ">"

By the by, you can do this kind of stuff without shutting down -- just hit
L1-A, diddle away, and hit 'c' at the > prompt to continue.  You'll want
to refresh your display, but it works fine.  I once laboriously typed in a
custom logo this way, only to have the machine move to another desk a week
later.