What Does It Take to Keep a Classic Mainframe Alive? | Hacker News Reader

What Does It Take to Keep a Classic Mainframe Alive?

spectrum.ieee.org

102 pointsamynordrum35 comments

The museum 1401 is insanely cool, but a mainframe it is not.

The 1401 was more of a service processor for a mainframe. You could use a 1401 to order jobs and manage card sorters and things of that nature.

The 1401 was occasionally sold as a standalone accounting machine instead of a service processor, but never as a mainframe unto itself.

It's more of a minicomputer than a mainframe. Which should say everything about its era. "Mini" meant only like, six racks of gear.

Fond memories!

I learned FORTRAN on an IBM 1401. Our intro chemistry professor thought it was a good idea to incorporate IBM's FORTRAN programming coursework into our chemistry lab. I wasn't so good at chemistry but excelled in programming and so earned a decent chem grade. In the years that followed I used the FORTRAN for numerical analysis classes. It all led to a career in programming.

I've seen the demonstration and I go there all the time. I LOVE computer history, it's our legacy, we're standing on the shoulders of the real pioneers. Those people who had to start from punch cards and mainframe terminals... they're the ones who really knew how to program.

What's crazy is it's so unknown to the general populace. Kids learn about George Washington and Bill Gates the businessman who gave us Windows, but they have no clue who Ken and Dennis are. Punch cards are meaningless to them. They wouldn't know an old hard disk from a vinyl record box. But one day they will. One day people will realize that this was the beginning of humanity. The real beginning. The PDP-11, the 1400 series, the ENIAC.

If you haven't been to the computer history museum, go!

> One day people will realize that this was the beginning of humanity.

It's important, but let's not engage in hyperbole.

He may be right. I don't think Gutenberg had any idea what he'd done, either.

The general populations would have to learn about thousands of people then in hundreds of fields. This notion that the general population "needs to know XYZ" is a requirement to keep celeb culture afloat, more than actual value to society. We live in the info age, which means people who are interested in a subject will easily find the people who made significant contributions.

You can run classic and modern mainframe operating systems and software with hercules-390 emulator.

I suggest Jay Moseley’s excellent site on MVS system generation [1] or get Jürgen Winkelmann and Volker Bandke MVS Turnkey installed system ready to go [2].

[1] http://www.jaymoseley.com/hercules/installMVS/install.htm [2] http://wotho.ethz.ch/tk4-/

The closest I ever got to a real mainframe was one time when I took over a failing datacenter and brought it up to t2...

It had a Cray 2 just sitting there, gathering dust. I loved the look of it. I think eventually they sold it just to make room.

When I was at college in the 70's, there was a surplus electronics store nearby. It was fun browsing it. They even had ferrite core memory modules. I wish I'd bought a couple of those.

That's awesome!

I started programming professionally back in 1990 on IBM mainframes. I used to daydream about buying an old machine to run in the basement. (But shortly after the 386 and 486 machines started hosting emulators that allowed mainframe programming on the desktop. My burning desire for a home mainframe died out.)

Good times....

They give out free remote shell accounts to a number of their mainframes actually, or if you go in person they encourage you to write code on the machines they have. It’s a “living” museum.

That's the Living Computer Museum in Seattle, this is the Computer History Museum in Mountain View (used to be in Boston).

Unless I'm mistaken and they both let you do stuff on the computers, which would be cool.

The Living Computer Museum, funded by the late Paul Allen, does indeed keep their computers running and offer accounts. You can request a login at the following link

https://livingcomputers.org/Request-a-Login.aspx

The Computer History Museum in Mountain View California has a few old computers running, but is mostly a display museum.

At the Living Computer Museum I logged into a DEC-2060 on a VT100 terminal and amazed my younger friends by navigating around the system and firing up a few ancient text based games. Being of the hacker mindset, I also showed them all the information you could get about logged in users prior to logging in from which one could have used to guess account credentials back in the day...

Explaining and demoing the COMND JSYS was quite fun. The COMND JSYS provided command line parsing and completion, one of the predecessors to t-shell, bash, and other shells with completion. I had a great time revising the past and highly recommend you visit with an old-skool programmer.

For those who are curious you can read about the COMND JSYS on page 164 (chapter 3, pg 52) of the following document

ftp://bitsavers.informatik.uni-stuttgart.de/pdf/dec/pdp10/TOPS20/AA-4166E-TM_TOPS-20_Monitor_Calls_Reference_Ver_5_Dec82.pdf

I hadn't realized the connection between the old Boston museum and the one in Mountain View. My recollection was that the collection went to the Boston Museum of Science when the museum in Boston shut down. That's partly true but its warehouse collection had moved to Mountain View earlier and other artifacts later. So the holdings ended up in both places.

They didn't make for good home computers. In college in 1991-1992, I was an operator for VAX/VMS mainframes, and some HP and DEC minicomputers. I wanted something to play around with at home, so I bought some surplus stuff that the school was auctioning. I can't remember exactly what I got, but it was a rack-mount DEC machine that weighed 100lbs or so, along with a similar-sized hard drive unit (that only held about 8MB).

The thing needed a 220V outlet, sounded like a jet turbine, and probably drew a few thousand watts. And it was less powerful than the i386 desktop I had (running early Linux).

It's a neat idea, but not practical or pleasant.

I see people buying all these old machines (everything from old DEC/IBM to newer non-mainframe SGI) and I'm super jealous for a few minutes. Then I consider the power-consumption. That's what makes me think, "hmmmm, maybe I'll just build a mini-emulation with a few Raspberry Pis or something". Yes, it would seriously not be the same at all. But having supported AS/400 with reel-to-reel tape drives... and huge greenbar printer... yeah, maybe emulation is just fine.

I worked on an OS390 for a little while and had a copy of the editor which ran on a PC. It was called SPF/PC and was pretty interesting and also allowed me to practice on it at home.

One thing, unique at the time I think, was you could selectively hide rows and then perform column operations on just the visible ones. Very handy when you needed it!

Until about 1990, if you owned a mainframe or a mini, anything that needed chilled air and a raised floor, you knew the vendor field engineer. Because the computer itself, the disk drives, or the tape drives broke and / or required periodic maintenance. pdp 11 was an outlier, as it was highly reliable (and slow as a turtle).

removeable disk packs were always a problem due to head crashes.

my point is, every computer had downtime due to poor reliability, when evaluated against what we have today. and most things were not 'user serviceable', unless your user was highly skilled in electronics, test equipment and digital logic.

In my field, once we moved to SGI's you started to see the salesman a lot more than the FE because the machines were so reliable. And today it is all commodity parts that anyone can cheaply swap-tronix things back to operational.

my old work gave me a microvax in the late 1990s. I rolled it out of work (security held the door open oddly didn't really check if I should be taking this thing), where it was used for cad. I got it working at home but honestly I didn't really have great software and buying anything additional was not easy at the compusa.. it ended up on the electronics scrap.

I give the computer museum credit for keeping this history in working order.

The microvax was two levels removed from mainframe land.

The original VAX systems, occupying 2 to 4 cabinets, were similar to the 1401. They were both "mini" computers -- smaller than a mainframe, but considerable and interesting unto themselves.

The microvax was a VAX re-implemented with much cheaper, cooler logic, so it could be sold as a desk-side or a single rack system.

I love computing history. For anyone in the UK, I recommend you visit the national museum of computing in Milton Keynes.

It has so many things to look and interact with.

Most notably the Colossus, Bombe, Acorn computers and BBC micros.

If you are visiting as a tourist it's not too hard to get there from central London by train or car.

Thank you for this tip: I saw your comment this morning and went today (am visiting London). Great stuff. Not as much vintage “modern” computing as the Computer History Museum in Mountain View but lots of amazing things, and of course lots about the Enigma and code breaking.

:D glad you liked it, I wish I could take commission for the amount of referrals I have given for it.

I take it you noticed the "politics" of Bletchely Park trust and TNMOC. Its sad that the two organisations fight over the heritage of that place.

And worth it to step inside Alan Turing’s office (to be clear, that’s in a nearby but separate museum at Bletchley Park).

Does anyone know the history of how they coined the term "Mainframe"?

> "The term originally referred to the large cabinets called "main frames" that housed the central processing unit and main memory of early computers."

https://en.wikipedia.org/wiki/Mainframe_computer

Interestingly, the term “mainframe” seems to have become exclusive to big iron only in the mid 1980’s.

If you read computer magazines from the 70’s, machines that we would call desktops were very often referred to as mainframes.

I respectfully disagree. In the 70’s, IBM 360s / 370s and such were “mainframes”, while PDP11s and the like were “mini computers”. As 8080 / Z80 machines started to appear, they were always “microcomputers”, eventually evolving into “desktops”, with higher-end ones “workstations”.

But “mainframe” was exclusively used for big batch and time-sharing iron sitting in a “machine room” that you weren’t allowed into unless you were employed as an “operator” or the IBM serviceman doing scheduled weekly PM (preventive maintenance), during which time no jobs ran.

But “mainframe” was exclusively used for big batch and time-sharing iron

In return, I will respectfully disagree with you, and back up my assertion with the following citations:

"Don't worry any more about wiring hundreds of wires in your Altair to expand the mainframe" - Byte Magazine, October 1975, page 21

"Need Altair IMSAI/POLY 88 mainframe, memory or what-have-you." - Byte Magazine, January 1977, page 98

"Our modular systems use common Vector 3 mainframes, boards, and printers." (Vector was a Z80A desktop computer that ran CP/M) - Byte Magazine, December 1980, page 89

"Z80 CPU, 4 Mhz, with one serial port; 12 slot S-100 mainframe, disk controller, 64K Dynamic Ram, CP/M 2.2... $1,645" - Byte Magazine, December 1980, page 156

"The OSI Challenger is the only completely- assembled, ultra-high-performance, fully-expandable mainframe computer that does this much for this little" (The OSI Challenger was a desktop computer) - Byte Magazine, November 1976, page 19

"MERLIN (trademark of MiniTerm Associates) is a new concept in peripherals modules for mainframe microcomputer systems." (Merlin was a dumb terminal for IMSAI and Altair desktop comptuers) - Byte Magazine, November 1976, page 64

"That's why we offer three mainframes including the Altair 680b, Altair 8800a, and Altair 8800b; ten peripherals including a multi-disk system; and over 20 plug compatible modules including our new, low power 16K static memory board." - Byte Magazine, December 1976, page 17

As I stated, it wasn't until the 1980's that "mainframe" changed to only refer to big iron.

The term "mainframe" was also used for the part of microcomputer cases that held the expansion cards, but they weren't referring to the computer itself.

It seems to come from microcomputer hardware and accessory companies trying to throw the word "mainframe" into their ads somehow and make their stuff seem more important.

While the term "mainframe" was common in advertisements, it was also used in the article text of magazines.

For example:

I only knew of "mainframe" used in the fashion that drfuchs described. Out of curiosity, I did a search of archive.org looking for uses which match your description. Here are two of the matches:

"Model 706 mainframe can accomodate 10 scanner plug-in cards. ... Before operating the Model 706, the appropriate scanner cards must be installed into the mainframe. Each scanner card (up to 10 cards per the Model 706 malnframe) is Installed in the appropriate vertical slot In the rear panel of the Model 706. Refer to Figure 2-1 for an overall picture of scanner card installation." https://archive.org/details/keithley_KEI_706_Instruction/pag...

"Peripheral cards, capable of handling words as large as 32 bits, perform operations normally requiring expensive computer mainframe expansion — display control, multiple capstan tape control and the like." https://archive.org/details/TNM_832_Data_Interface_-_ECG_Dat...

However, that isn't what reaperducer referred to when saying "the term “mainframe” seems to have become exclusive to big iron only in the mid 1980’s."

Here's an MS thesis from 1971 titled 'The minicomputer : an educational tool', which makes considers the "mini-mainframe" as a distinct category. https://archive.org/details/minicomputereduc432mars/page/62

Here's how a 1974 publication titled "Role of the Minicomputer in Small Educational Institutions" characterizes minicomputers, quoting https://archive.org/details/ERIC_ED100376/page/n3 :

> What is, a minicomputer? Unfortunately, the term minicomputer is used by many people with many different meanings. For the purpose of this paper, we shall characterize a minicomputer by the following two criteria.

> (1) Physical size . Typically, the main components of a minicomputer (its CPU and main memory) are closer to the size of an electric typewriter than, say, a washing machine. (Not counting the power supply and racket, the CPU and memory may fit on a single printed circuit board!)

> (2) Cost . Typically, the main components of a minicomputer (its CPU and main memory) can be purchased for less than $10,000 - in some cases for less than $1,000.

This is clearly more like a machine we would call a desktop - how many people have washing machine-sized computers on their desktop?

A 1975 report titled "Use of Minicomputer Facilities for Higher Education Instruction" helps identify that 'minicomputer' was a new computer category starting in the late 1960s, quoting https://archive.org/details/ERIC_ED112763/page/n3 :

> Although each of the methods offered a level of computing suitable for some instructional use a belief was expressed in 1969 that the new "minicomputers" might be able to provide instructional computing support that even the smallest colleges could afford.

> machines that we would call desktops were very often referred to as mainframes.

I suspect you're misinterpreting what you are seeing, those adverts probably showed someone working at a keyboard and VDU screen. They aren't the computers, they are just terminals which connect to the computer. Have a look at the links below for some examples.