Replacement for wind.o

david.e.wexelblat dwex at cbnewsj.att.com
Sat May 4 02:32:20 AEST 1991


I am planning to put together a small replacement for wind.o for 3B1
systems that have pitched UA/wind.o.  Basically, I am tired of
the glass-tty when logged in without running MGR, and also want
a screen-blanker that runs without MGR (I don't want to give up
my loadable-driver space to wind.o for the small amount I need done).

What I intend is to have a window driver that provides:

	- screen blanking, and can accept ioctls from scrset
	  (I see no need to have yet another program to do this)
	- a vt100-subset console.

I figure that I can get the screen blanking done pretty quickly; I
have most of the interface figured out (anyone who knows how this
is implemented in wind.o is free to help me out :->) from looking
at the nkbd.c sources and a bit of judicous adb'ing.

What I haven't figured out yet is, once I have this running on
/dev/syscon (or whatever), how do I make the driver know to
stop interpreting characters, and just pass them on when MGR is
running?  I've thought of a couple of schemes, which may be
equivalent:

	- create a /dev/framebuf device, with the same major
	  device as /dev/syscon, but a different minor
	  number.  When MGR opens this device, the character-
	  interpretation stops.  This allows getty to hang
	  off of /dev/syscon, and when MGR exits, things
	  go back to normal.
	- have an ioctl() to do the same thing, and have MGR
	  call this on startup.

Actually, it just dawned on me that MGR doesn't write to /dev/syscon;
it writes directly to the frame buffer.  So if my driver just implements
write(), then there is no problem (except for turning off cursors and
stuff, since I like blinking cursors).

Please email me your suggestions, or post followups to comp.sys.3b1.
I will take all suggestions into consideration, and will post the
results when I am happy with it (which may be never - I have a
tendency to get too fancy for my own good :->).


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David Wexelblat             | dwex at mtgzz.att.com    | I asked her her name.
AT&T Bell Laboratories      | ...!att!mtgzz!dwex    |   She said her name was
200 Laurel Ave - 4B-421     |                       |      'Maybe'
Middletown, NJ  07748       | (201) 957-5871        | --Damn Yankees



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