Adding a new disk in RSX-11

[Jeremy Doolin]

I've recently decided to explore RSX-11 in more depth. One of the first things I like to do is create my own user account, which is easy enough. But to make things more interesting, I thought I'd add a separate disk for my user account(s) UFD. 

In boot.ini I added:

attach rq2 PERSONAL_DU2.dsk

Booting the system creates the .dsk file just fine. I then explored the MOU(NT) and INI(TIALIZE) commands, but neither of them work. Official documentation refers to a FMT command to format storage, and while the HELP files seem to exist, the FMT command does not on the PiDP11 system 

So I must appeal to those with more experience for assistance. Might anyone be able to assist with this?

Jeremy

[Johnny Billquist]

Hi.

Ok. So FMT (formatting) can be done, but it is something you normally
*never* do. So let's skip that bit for now.

What you need is to first create a file system on the device. The tool
for that is INI (yes, short for initialize).

I'll start with assuming you are in an account using MCR as the CLI.
Basically, the prompt is ">". If not, let me know.

Before you can initialize a disk to create a file structure, the disk
needs to be mounted. But since you don't have a file system, you need to
tell the system that you want to mount a disk without a file system on
it, and for initialize to be happy, you also need to have exclusive
access to the disk.

There are two ways to accomplish this. The perhaps more appropriate way
is to start by allocating the disk. That means you'll have exclusive
access to it until when you deallocate it. So "ALL DU2:" will do this.

Alternatively you can also mount the disk with /NOSHARE, which will make
it exclusive to you until when you dismount it.

The next step is the mounting, which you need to do using the /FOREIGN
switch, to tell the system that the disk does not contain a file system
(or that you are not interested in the file system). So "MOU DU2:/FOR"
will do that.

Once you've come that far, you can do the optional step of scanning for
bad blocks. "BAD DU2:" will do this, and will create a record with
information about bad blocks on the device, which INI will use. If you
don't do this step, INI might complain that it didn't find any such
information, but will otherwise be fine.

After this, you create the file system with INI. "INI DU2:FOO" will
create a file system with the name FOO. That name is mostly just used
during mounting to verify that you actually are mounting the file system
you think you are.

Once this complete, you dismount the disk. "DMO DU2:"

And then you can mount it with a file system. "MOU DU2:FOO". But that
means it's just mounted for your session, and noone else can access it.
In order for it to be generally accessible, you need to mount it public
with /PUB. Also, don't forget to deallocate the disk at this point, if
you allocated it before.

And finally, you might want to mount that disk in LB:[1,2]STARTUP.CMD,
so that it's available whenever the system boots.


Now, if any of these commands fail with a "Task not in system" error, it
means that tool has not been installed. It don't mean the tool don't
exist, but just that the system currently don't know about it.

You can run tools that haven't been installed. They are usually in
LB:[3,54], but you can also refer to them by $, which is a shortcut for
that directory.

I hope that helps.

Johnny

[Jeremy Doolin]

Yes, this helps immensely, thank you. I learned some things about how RSX thinks about things just in this small exercise. 

As for editing STARTUP.CMD, I assume I'm just adding "MOU DU2:FSNAME" somewhere in the file, since this is essentially the equivalent of a shell script. 

Does it matter where in the file? Is there a convention that RSX admins would follow? If so, I'd prefer to do that. 

Jeremy

[Johnny Billquist]

You want to mount if before you reference it. But there is nothing more
than that. You can create your own system or conventions on where you
place things in STARTUP.CMD.

And don't forget to mount it public, or it will be dismounted when you
log out...

Johnny

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[Jeremy Doolin]

Ok, everything has gone fine so far until I tried to modify STARTUP.CMD

I added this to about line 63:

MOUNT DU2:PERSONAL/PUB

I see an error when starting:

MOU: unit offline

That error I assume is from the disk I'm trying to mount. 

[Johnny Billquist]

On 2026-10-06 19:07, Jeremy Doolin wrote:
> Ok, everything has gone fine so far until I tried to modify STARTUP.CMD
>
> I added this to about line 63:
>
> MOUNT DU2:PERSONAL/PUB
>
> I see an error when starting:
> MOU: unit offline
>
> That error I assume is from the disk I'm trying to mount.

So where did you add that line? Because when the system comes up, pretty
much no devices are online. A little bit into the STARTUP.CMD, where is
a CON ONL ALL, which brings all devices online.
Obviously that needs to happen before you can play with most devices...

Dependencies... It's a little hard to get all that clarified when
writing a mail, so in general it's easier to comment when you have an issue.
And I do hope it's just this simple, and not something else...

Johnny

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[Jeremy Doolin]

Perfect, that's exactly what it was. I added the MOU command a few lines after CON ONL ALL and it worked.  I also learned a few more EDT commands while I was at it.

So now I should be able to assign DU2 as the disk for my new user accounts. I'm going to give that a try, thanks! 

Jeremy