Path: utzoo!attcan!uunet!samsung!usc!snorkelwacker!bloom-beacon!eru!luth!sunic!mcsun!hp4nl!phigate!philica!adrie
From: adrie@philica.ica.philips.nl (Adrie Koolen)
Newsgroups: comp.os.minix
Subject: Re: Assorted questions
Message-ID: <630@philica.ica.philips.nl>
Date: 17 Jul 90 11:11:21 GMT
References: <877@sce.carleton.ca> <628@philica.ica.philips.nl> <1990Jul16.235145.25212@jarvis.csri.toronto.edu>
Reply-To: adrie@beitel.ica.philips.nl (Adrie Koolen)
Organization: Philips TDS, Innovation Centre Aachen
Lines: 47

In article <1990Jul16.235145.25212@jarvis.csri.toronto.edu> wayne@csri.toronto.edu (Wayne Hayes) writes:
>In article <628@philica.ica.philips.nl> adrie@beitel.ica.philips.nl (Adrie Koolen) writes:
>>The problem with the one-threaded FS is mentioned regularly in this
>>newsgroup and I agree: it has to be fixed. On my SparcStation, I use a
>>multi-windowed TTY driver and I suffer the single-threadedness
>>continuously when in one window, a `make' is started, or another disk-
>>intensive process, like `find' or `tar', and I want to edit a file in
>>another window.
>
>Err, how did you get Minix to perform in windows?  Is Minix running as
>the actual OS on your Sparc, or just a user process faking an OS on top
>of the real SparcUnix OS?  If it's the real OS, HOW THE HECK did you get
>it to run windows???  Is this something we other Minixer's might be
>interested in?  "MXwindows"  :-) ?

Minix for the SparcStation 1 will be a completely autonomous operating
system. It doesn't use the original Sun Unix, SunOS. Only the Minix
boot-image has to have a SunOS header in order to be able to let the
monitor load the image. Because Minix for the Sparc is an independant
O.S., I had to (re)write all the device drivers. Because the SparcStation
has a large (1152 * 900) bit-mapped display, I used the Atari-ST TTY
driver as a basis. The screen is too large to be used for just a single
window, so I rewrote spvdu.c (and a few changes in tty.c) to split the
screen into more windows. There are three fixed sized windows now and
there's no way to change the position of the windows other than
recompilation of the driver. The TIOCGETWINSZ ioctl is used to inspect
the window size, so that elvis, more an man work correctly. A special
key is used to select the window to which keyboard input is directed.

It would not be too difficult to dynamically create, move and resize
windows with special keys and/or the mouse, but I know that I would
constantly add more features and I've no time to do that. Maybe, that
somebody will port the X Window System to Minix for the SparcStation
somewhere in the future. It shouldn't be that difficult; Minix only
lacks a real ethernet driver and the socket mechanism.

Rewriting the TTY task of Minix-ST to support multiple (ASCII) windows
is quite easy. I'm not sure whether the display is large enough
(640 * 400) to make multiple windows workable. On the SparcStation, I
can use the 8 and 16 pixel fonts, but I also added a font of 12 pixels
high, which I use mostly. I've always wondered why the Atari guys
didn't add an extra intermediate sized font, because 8 pixels is to
small, 16 is quite big and with 12 pixels, you can make a good and
readable font and get 33 lines on the screen!

Adrie Koolen (adrie@ica.philips.nl)
Philips Innovation Centre Aachen