Newsgroups: comp.os.minix
Subject: Re: Minix on Sun?
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Organization: Rochester Institute of Technology, Rochester, NY
From: aje9383@osfmail.isc.rit.edu (Andrew Erickson)
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In article <0eXzARA2yJG3EwD6@dbqa.demon.co.uk>,
Tom Bird  <hamster@nospam.demon.co.uk> wrote:

><Stuff about a SUN-3 workstation and minix porting and such>

>In article <3713902c.0@isc-newsserver.isc.rit.edu>, Andrew Erickson
><aje9383@osfmail.isc.rit.edu> writes
>
>>No, the port would not be extremely easy (although certainly not
>>impossible).  You would need to write drivers for all the hardware you
>>wanted supported--at least the keyboard, disk, and display.  You'd also
>>probably want to write in support for the MMU on some level to avoid having
>>to use shadowing.
>
>The keyboard and text mode display should already be in stdio.h or
>conio.h (it's ages since I did any C so excuse me if it's wrong)
>probably?  Since the machine no longer has a HDD (deader than a dead
>thing), it'll need network support.  NFS support actually which kind of
>puts a damper on things as Minix doesn't do NFS (yet...).

Ummm....no.  stdio.h relies on the kernel to do actual I/O with devices;
that's how the same program can work, without changes, with the console
interface, a terminal on a serial port, or a network session.  stdio.h
handles buffering and formatting of intput and output--but does not perform
the actual I/O beyond writing to a file system special file (which causes
the actual data to be sent to or retrieved from a device driver).

The text mode display and keyboard interface are, to a certain degree,
handled by the boot monitor; whether or not one would want to (or be able
to) use these built-in drivers for the operating system, I don't know.

The text mode display is really just software drawing characters in the
graphic framebuffer; the workstation does not have a "text mode" per se. 
The keyboard and mouse interface through some UART chip.  Realistically,
getting a tty driver may be a tiny bit easier than a console driver; the
serial ports are through an 8530 SCC.

Any (narrow) SCSI hard drive should work; it would be *much* *easier* to use
some old (but working) hard drive from whatever than to create an NFS layer.

>I have seen the version of netbsd that should run on this and I have
>also found a site where I can download SunOS 4.1.1

Either one will require significantly less work than Minix, since they are
already known to work with a SUN-3 (rather than known not to work yet). 
They are both more functional than Minix is--they support paged virtual
memory, more netowrk stuff, X, etc. etc.  Minix is wonderful at what it is
designed to do (provide an understandable and accessible platform for
studying operating systems), but it is not particularly great at being a
proper workstation OS.

>TB

-- Andrew Erickson, aje9383@grace.isc.rit.edu
May your workstation disks become deader than a dead thing if you send me
unsolicited commercial Email.
