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July 17, 2020

Logon advice launches new 3000 admin crop

Row of Lettuce
By George Stachnik

There's a new crop of people taking over management of these machines. Many of the people who have managed and championed HP 3000s in the past have moved on. Today's HP 3000 system manager is now more likely to be young and have little HP 3000-specific experience, knowledge, or training. New HP 3000 system managers have been successful managing environments that include Unix, and Windows. Now they've been given responsibility for an HP 3000, a machine about which they know little or nothing.

If you fit in this category, take heart; I think I have some understanding of what you're going through. When I encountered my first HP 3000 in 1983, all of my experience had been with IBM machines. I was glad to hear that the HP 3000 is comparatively simple and elegant to use (at least compared to a mainframe), but I was still expecting a long learning curve.

For many customers, information about the HP 3000 — especially beginners' information — can be hard to come by.

Logging on

In Lewis Carroll'sThrough the Looking Glass, Alice is encouraged to "Begin at the beginning." This always seemed like good advice to me, and that's what I'll do now. Let's begin by exploring how one logs on to an HP 3000. We'll also see how to explore your system, and find the programs, files, and information that are available to you. We may even learn a few other things along the way.

You're likely to have a PC or workstation sitting on your desktop. In that case, you need two things: a physical connection between your desktop and the HP 3000, and a piece of software that lets your desktop computer act as if it were an HP terminal--a terminal emulator.

The desktop-to-3000 connection can use the same RS-232 protocol used by terminals. But a network connection using standard IEEE 802.3 or Ethernet is preferable. All you need to know is that the HP 3000 supports industry-standard telnet services, and you can use them to log on to an HP 3000 from your desktop computer.

If you're using a Windows PC on your desktop, a number of HP terminal emulators are available. Among the best are WRQ's Reflection series from Attachmate, and Secure92 from Minisoft. PC-based terminal emulators support industry-standard telnet services to connect to hosts like the HP 3000. Reflection and MS92 also support the NS/VT proprietary protocols.

Regardless of what kind of terminal or terminal emulator you've connected to the HP 3000, pressing the RETURN key (on a PC, it's usually labeled the ENTER key) will cause the HP 3000 to transmit the string "MPE/iX:" back to you. This is a prompt from the HP 3000 inviting you to log on. It's analogous to Unix's "login" prompt.

Incidentally, if something other than "MPE/iX" appears on your screen, don't panic. The system prompt is configurable and your system manager may have changed it. Regardless of the prompt that appears, the command you'll use to log on is always the same. It's called the "Hello" command. (Didn't I tell you that the 3000 is a friendly little machine?)

The HELLO command you enter will typically include two parameters separated by a period. These two words identify you to the system. The first one is your user name, and the second one is your account name. When you log on, at a minimum you must specify a user name and an account name. If there are passwords associated with your user and account (and there should be!), you will be prompted for them.

When you've entered all the necessary passwords, the HP 3000 will display a message that identifies the system you've logged on to (called the "Welcome Message" in MPE-speak) and log you on to the system.

What happens next depends on how your system has been set up. Frequently, system managers configure their HP 3000s so that menu programs or applications are executed automatically upon logon, and exiting those applications causes you to be automatically logged off the system. You never interact with the operating system directly. So if you log on to a 3000 and are suddenly confronted with an application program, a system manager has set up your particular user and account to work that way. 

User and Account Name

Ordinarily, the system displays a prompt on your screen that ends with a colon (:). This is the HP 3000's way of prompting you for an MPE command. I'm going to explain a few of the most basic and frequently used MPE commands, and at the same time explore some of the basic concepts and ideas behind MPE.

I'll begin by raising a few questions about your user and account name (the two parameters you entered in order to log on). Why are there two? After all, you need only one name to log on to a Unix machine. Why does the 3000 require two logon names?

To answer that question, we need to explore how HP 3000s (and most other minicomputers) were used in 1972, when MPE/iX was originally designed. In those days, computers (even HP 3000s) were very expensive--too costly for most small-to-midsize companies to own. Personal computing was more than a decade away, so (capitalism being what it is), an industry called "time-sharing" had sprung up. You might be thinking, "I thought that time-sharing had something to do with vacation homes." But in the early 1970s, time-sharing companies purchased computers (such as HP 3000s) and allowed other companies to share them (in exchange for a fee).

Here's how it worked. Imagine you're the owner of a time-sharing business. You buy an HP 3000, and provide your clients (the owners of small businesses who don't have computers of their own) with terminals and dialup lines so they can share your computer. They installed their applications on your machine, and at the end of each month you'd bill your clients based on how heavily they used your computer. As you can see, it becomes very important to be able to track who was doing what with the machine.

What does all this have to do with the account and user ID you entered when you logged on? Suppose your time-sharing company had signed contracts with three clients: Tom's Dry Cleaners, Harold's Used Cars, and Dick's Bar and Grill. You might set up three accounts on your system and call them something like TOM, HAROLD, and DICK.

On the HP 3000, accounts are tools for keeping track of who is using the system's resources--CPU time, memory, disk space, and so on. For example, each account has a timer associated with it. When somebody logs on to an account, that account's timer begins ticking like a taxi meter.

When the TOM account's meter begins ticking, Tom's Dry Cleaners is charged for the time you spend on the machine. (To see how you can use MPE commands to display these "taxi-meter" timers, see the sidebar called "Listing Accounts and Users.")

But what if one of the time-sharing company's accounts requests a detailed breakdown of its bill? Suppose, for example, that Harold's Used Cars employs three salesmen named Moe, Larry, and Curly. (Hey, I didn't say it was a good used car company.) When Harold gets his bill at the end of the month, he's probably going to want to know what portion of it is can be traced back to the activities of each of his salesmen.

MPE requires that when Moe (or any other user) logs on to the system, he doesn't just log on as "MOE" or as "HAROLD" but as "MOE.HAROLD", specifying both his user name and his account name. In this way, Moe actually kicks two timers into action. One is associated with the HAROLD account and accumulates all the time logged by any and all HAROLD users. The second is associated with MOE.

Each HP 3000 account has a password to protect it from unauthorized usage. Each account also has a number of users associated with it, and each also has (or at least should have) a password of its own.

Each user name is associated with one and only one account. In other words, you cannot log on to an account unless you have a userid that belongs to that account. For example, Moe works for Harold's Used Cars. Therefore, his username has been tied to the HAROLD account, and he must log on as "MOE.HAROLD". He can't log on as "MOE.TOM" or "MOE.DICK".

In this sense, each account can be thought of as being a collection of related users. MPE accounts are similar, in this respect, to Unix Group IDs, or GIDs. MPE systems have a number of concepts in common with Unix systems, although the terminology and details often differ.

Photo by Kenan Kitchen on Unsplash

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