> Now technology relentlessly marches forward and you can "create" this time
> sharing architecture in a "single user" machine. No way you're going to get
> $30,000 for software for that machine, so you dress it up for the end-user
> (leave out serverish things, add a frame buffer) and call that a VAXStation.
>
> But wait, its actually just a VAX underneath and maybe you can capture a
> few bucks by selling it to people who _want_ a time share system, but they
> don't have a machine room. Now we'll call that a "MicroVAX".
>
> Same hardware, different target, different name, and more importantly,
> software for the MicroVAX was _much_ more expensive than software for a
> VAXStation since it was for multiple users.
There are hardware differences. Different bus, different design with
different RAM addressing limits, different cache, etc.
> It used to be that people found this out the hard way when they removed the
> frame buffer cards and suddenly the OS believes its on a MicroVAX rather
> than a VAXStation and the license PAKs all refuse to work.
>
> So the only difference between a MicroVAX 3100 and a VAXStation 3100 is
> that the ROM of the latter complains when there is no frame buffer :-)
Not quite. The MicroVAX 3100 and the VAXstation 3100 are completely
different beasts. I have examples of both. The VS3100 has a frame
buffer built-in to the motherboard, but you can change S3 to make
the printer port the console port and run headless, and VMS won't
complain, but you'll still have the same user limits as you would
with the frame buffer. The MV3100 has extra serial ports and there
isn't a built-in frame buffer and no connector to add one.
When you pull the frame buffer from a VAXstation II it becomes a
MicroVAX II. The VS3100 is still a VS3100 when you use a serial
console.
A VAXserver 3100 is a MicroVAX 3100 with different ROMs so it will
by default only run a couple of local users (but that can be changed
with the appropriate licenses).
> You can run them both headless or with heads, both will run VMS 7.2 (the
> latest), and both will run NetBSD 1.5 (also the latest). The Hobbyist
> licenses (currently screwed up at the moment) work in either mode.
V7.3 is the latest for the MicroVAX 3100. I'm not sure whether support
for the VAXstation stopped at V7.2 or not (it isn't in the SPD).
--
Eric Dittman
dittman_at_dittman.net
Received on Sun Jul 08 2001 - 19:04:20 BST