Re: VSTa

[John Burton <john@bilton.demon.co.uk> writes:]

> I've been given your name as the person to contact about a new operating
>system called VSTa. I believe it is free along the lines of linux? I know it is
>not really in a usable state yet, but would be interested in knowing what
>you are working on?

Welcome to the world of VSTa. I've added you to the mailing list; it's
vsta@cisco.com. Changes and miscellany go to vsta-request@cisco.com.
VSTa is freely available, but along the lines of GNU, not Linux. All
the source is under the GNU Public License. At some point in the future
I'll probably move the library portions to the version of the GPL which
GNU uses for *their* libraries.

VSTa is quite different than your typical free UNIX. First, it does not
even try to be exactly a UNIX; areas which have proven to be problematic
for extensibility or efficiency have been changed. For instance, signals
are strings, as are error "numbers". Thus, VSTa is much more of a platform
for experimentation with "beyond UNIX" ideas than simply another implementation
of UNIX.

The other major difference form "classic UNIX" is that VSTa is a microkernel.
The microkernel provides messaging, processes, and virtual memory. All
filesystems and device drivers run as user-level tasks. The kernel is 40K,
and has remained at this size for quite a while, while the system as a whole
has gained significant functionality.

Where we stand today? We have servers for: pipes, environment variables
(environment variables are hierarchical and can be shared among processes),
a virtual memory based /tmp filesystem, /dev/null (a very small server),
a DOS filesystem, IDE disks, floppy drive, MGA/CGA console, AT keyboard,
swap management, name to port mapping, and a simple boot filesystem (no
longer used, really). We have most of a C library, and many commands.
I've written many commands from scratch, simply because I can't bear
to bring over the gargantuan versions which are freely available.

I am writing a contiguous-allocation filesystem, which is up and
running--I'm now doing the fsck program for it. Gavin Thomas Nicol is
writing a window system, called MADO. David Johnson is working on an
ethernet driver, and Michael Larson is working on SCSI support.

Version 1.1, now in the home stretch, adds my filesystem, puts in a bunch
of bug fixes, and tidies up the source tree. It also fixes a number of
makefile problems, and has been built from the freely-available pdmake
program. If you really want to start playing with the system NOW, I can
get you a copy of the current source. Otherwise hold on for a week or
so and you can run with 1.1, which should be easier to bring up.

                                        Regards,
                                        Andy Valencia
                                        vandys@cisco.com
Received on Wed Oct 27 08:50:28 1993