Some users swear by Aqua interface of MacOS X, others proclaim the desktop-readiness of Linux, the polished presence of Windows XP, or expound upon the stately Solaris as the ultimate operating system. All of these users are wimps.Back in the old days, programmers toggled in boot code on front-panel switches,
submitted jobs through JCL, and counted on a 24 hour operations staff to feed in
the tapes for massive 5Mb datasets of accounting information. Portability
was a pipe-dream, and computer time was far more valuable than that of the lowly programmer.
Many of these operating systems and their descendents are still around. IBM’s phenomenally successful OS/360 is now the 64-bit z/OS, and still provides IBM with billions of dollars in yearly revenue. The market for firms running “modern” versions of PDP-11 operating systems like RSTS, sometimes on original 1970s hardware, is relatively tiny. Nevertheless it still supports several small businesses.
What choices does a retrocomputing hobbyist or OS junky have for taking one of these old OS for a spin? You could choose to troll Ebay for spare parts and dedicate the rest of your budget to expensive air conditioning units and spectacular power bills. But fortunately, thanks to talented and nostalgic programmers, many ancient operating systems will run under emulation via free software packages on Windows, MacOS X, Solaris, and Linux.
We’ll take a quick look at two of the more powerful emulators available, SimH and Hercules.
SimH – The Computer History Simulation Project
SimH, http://simh.trailing-edge.com/, originally developed by Bob Supnik of DEC, is a spectacular general-purpose emulation package. Focusing on DEC equipment, it also is capable of emulating computers produced by many other manufacturers. Thanks mostly to Mr. Supnik’s many contacts, licenses are available for hobbyists to try out an impressive variety of operating systems.
The following is the list of computers emulated by SimH:
Data General Nova, Eclipse
Digital Equipment Corporation PDP-1, PDP-4, PDP-7, PDP-8, PDP-9, PDP-10,
PDP-11, PDP-15, VAX
GRI Corporation GRI-909
IBM 1401, 1620, 1130, System 3
Interdata (Perkin-Elmer) 16b and 32b systems
Hewlett-Packard 2116, 2100, 21MX
Honeywell H316
MITS Altair 8800, with both 8080 and Z80
Scientific Data Systems SDS 940
A long list of operating systems distributed in easy-to-use kits is available here: http://simh.trailing-edge.com/software.html
Most notable among the operating systems SimH allows you to run are the following:
- Unix V5, V6, and V7 for the PDP-11. Try out the first versions of the Unix operating system on the virtually original hardware.
- TOPS-10 and TOPS-20, mainframe 36bit operating systems from DEC that lost out internally to…
- VMS, runnable on an emulated VAX. There are still quite a few jobs out there that call for VMS skills. The hobbyist license program will let you get started on a modern version for $20.
- CP/M on the Altair 8800. See MS-DOS’ predecessor in action!
SimH runs on Linux, MacOS 9 & X, Solaris, Windows, and many others.
Hercules – System/370, ESA/390, and z/Architecture Emulator
Hercules is an emulator for IBM mainframes. The IBM 360 series dominated computing for years, and even today is an important segment of the market. Hercules will run an enormous variety of operating systems, from the ancient OS/360 to modern-day z/OS and Linux/390 (Linux on the mainframe). The problem is that you can’t actually run modern z/OS without a massively expensive license from IBM.
So other than as way to check out how Linux works on system whose native character set isn’t ASCII, what good is Hercules? Well, all of the old IBM operating systems were not copyrighted. From ancient reel-to-reel tapes have been dredged OS/360, DOS (no, not that DOS), VM/370, MVS, MFT, MVT and others.
Besides Linux/390, the two operating systems available freely for Hercules are most of interest for hobbyists are
- MVS: A strongly batch-oriented operating system, MVS’ descendants, OS/390 and z/OS, rule the mainframe market. The latest free version of MVS, 3.8J, has been nicely packaged onto a turnkey CD for Linux and Windows. The CD includes compilers for languages like ALGOL, COBOL, PL/I, FORTRAN, and RPG.
MVS is an extremely robust operating system, and not for the faint of heart. Even by “old school” standards it is spectacularly complicated.
- VM: Much more user-friendly than MVS, VM survived many periods of official neglect due to its vocal and enthusiastic user-base. VM presents each user with his own virtual machine, complete with its own memory, printer, disk space, and even virtual punchcard reader. Typically a user would run CMS inside his virtual machine, but the key is that he could run *any* mainframe operating system, including VM under itself. There is, of course, a small performance penalty for the overhead. Think VMWARE. The difference is that because unlike x86, the 360-series is completely virtualizable. This means one can run an instance of VM under an instance of VM under an instance of VM under an instance of VM…
The modern incarnation, z/VM, has gained a new lease on life recently from the popularity of linux on the mainframe. With VM, a mainframe can run hundreds (the record is more than 40,000) of independent copies of the Linux operating system on a single physical machine.
The most recent freely available version of VM is VM/370. A pre-built system that comes with lots of installed software has been prepared, but it’s quite lacking in documentation. You’ll need to do a bit of reading to figure out how to sign on and start using VM, but it is intrinsically much more user-friendly than MVS
Hercules runs on Linux (including Linux/390 if you happen to have access to a “real” mainframe), Windows, and now MacOS X.
In addition to the Hercules software package itself, you’ll need a 3270 terminal emulator. I suggest QWS3270 for Windows or x3270 for Linux, MacOS X, and other Unix-like operating systems.
Hah! My day job is a mainframe programmer for the State of Alaska. Using OS/390, with TSO, Roscoe, and CICS as the interfaces. Heavy use of Cobol and Natural for application development. As of this year, my department is the ONLY department that uses the mainframe, every other department got a brain and switched to more cost saving solution, aka NON-MAINFRAME!
So, our department is planning on phasing out the mainframe junk in 5 years and move on to better things. We are currently in the transistion stage, converting all of our cobol and natural code/programs to dotnet.. yay.
Oh well. As I was reading more and more of this post, I just started laughing. This is clearly a joke and it isnt even April Fool’s Day yet!! hahaha, oh well. It was a great laugh.
Oh yay, Im first post! Or was at the time of typing this.. donno if it’s true now..
I went back and read the article. Realized that this guy was talking about emulators for the mainframe… I guess the joke is on me, heh .
the VM operating system sounded very cool. 40,000 VM’s running at once? wow. This is just good stuff.
Well this is definitely the coolest article of the week. Jeff Boulier not sure if you are involved or just posting this but either way thanks.
Shannara –
I don’t know why you think OS390 (now zOS) is junk. I think you’ll find what ever you switch too to be a downgrade. Maybe you haven’t updated your hardware or software enough or something but the zSeries are great machines anything else is at best moderately less functionality for a lot less money.
When I first got into IT, it was then called “Data Processing’ in the very early 80’s, the shop I worked at had an IBM S/370 mainframe running VMS, CMS and God knows what else.
I used to sneak into the Systems Programmer’s office at night and study the manuals because I was curious. I even crashed a VMS job and had gained enough skill to somewhat cover my tracks.
Later on, they got an IBM S/38, one of the AS/400’s parents, and we were amazed at the relational database system it ran.
I may grab one of these emulators and see if I can get VMS running just for fun and memories
Glad you liked the article! I had a good time writing it, not to mention playing with all those old OSes. I’m not clever enough to be involved in developement of those emulators, but I’m happy to try to get the word out!
Yours truly,
Jeffrey Boulier
Not sure were to post this but I’m having problems loading up osnews on Opera 7 (I tried sending different idinenty strings with opera) and IE 6 but it’s working on phoenix. I tested other pages with both browsers and they work fine but this site won’t load
Own your own Main Frame right now
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3405163151&categ…
A Nice UNIVAC III for sale $10000, it needs a good home. I would buy it but im poor.
I think you want IBM’s VM/370; if you install DEC/Compaq/HP’s VMS you’re going to be very surprised! VM was a walk through memory lane for me as well. My first real job was migrating users from my University’s VM/SP [HPO] mainframe to Solaris.
Never had the chance to work on any of the AS/400 vintages, but I’ve always been a admirer of the design concept. It might be fun to pick one up off of Ebay — small ones are PC-sized and not particularly expensive.
Yours truly,
Jeffrey Boulier
My God! I’m glad I read this article – my own copy of MVS – bliss!
Because we all know that anybody that actually uses a computer is a wimp.
Aaah, memories… Started working on IBM mainframes in ’79 or so (holiday job). Joined the System Operations department for real some years later. About 8 IBM mainframes ranging from a 3033 to 3081&83s and, in the end a 3090 all running MVS or VM. Oldest disks (3330) had disk ‘packs’ that had to be screwed in. Later, the diskfarm grew to the size of a fotballl field. There was also this giant Mass Storage System (3850) with honeycombed interior containing data cartridges. VERY impressive. And if you think your LaserPrinter is fast, you clearly haven’t seen a 3800 in action. “System Operations Analist” the job was called. Started out mounting tapes the whole night, then moved to the 3800 printer and finally to the consoles running batchjobs all day&night, rebooting mainframes. Weird, all that cutting edge technology from way back then now reduced to junk and memories.
Just a little note, VMS was the native OS for the VAX. MVS however was what ran on the IBM S/3×0, ES9000 and maybe still runs on the Z-series.
We still have some of those old Mainframe printers here at work. Plain text only but they print out pages of data very, very fast.
Managed an old beaten MicroVAX 3900 during my military service (94-96). Inlove with VMS and DCL ever since.
funny
Didn’t Fred Brooks, who was responsible for this OS line, consider it a technical failure despite being financially successful? IIRC, he found it wasn’t designed cohesively enough (he used a lot of not-so-good programmers vs. a small ninja team) and believed that it’s not the sort of OS that would attract a vibrant community like BeOS or OS/2.
(engage smug mode)
…why not run an edsac (1949) – http://www.dcs.warwick.ac.uk/~edsac/
Which was the basis of the first business computer the Leo (1951) http://www.leo-computers.org.uk/pageone.htm
Great article, Jeffrey! I’m going back to read it again!
I started working at my current job about two months ago – I do java development. Anyhow, when I got here this was the first place I’ve been that still has OS/390 in use. I’m at a hospital that I’ll leave unnamed.
Anyhow, I just thought it was funny that I read this article after being plucked down in a cube right in the middle of all these ‘dinosaur’ it guys still writing stuff in cobol and JCL.
I think I’ll remain a pure spirit and dodge the emu, but hey, it was a great read.
You guys have been running some good articles lately. It’s nice to see something different.
Have you checked out mess or its cousin mame?
BTW, I am still pumped about that C=64 webserver.
Jeffrey-
Cool article. I’d never even heard of half these things. I suppose it would be cool to screw around with them for a little bit, but I just don’t have the time to learn to use them. Ah, well…at least I can read articles like this and, at least, learn a little about computer history.
I really don’t think this kind of flame bait is neededto draw attention to an article. I would suggest just tellng us what you’re going to tell us.
…to get a day job doing mainframe programming
(COBOL,JCL,DB2,EASYTRIEVE) so you can work somewhat
“normal” hours (i.e 7-9 per day) (as opposed to a
many PC programming jobs where you’re doing 12+ hour
days) so you can
a) have more of a life
b) have more time outside of work to spend
programming the stuff you really like
(for me C++, x86 assembly, and PHP)
Yeah, I don’t make as much money as some C++,
Java, .net type programmers but I do pretty
good financially and the mainframe job market
seems a little more stable than the PC programming
market. Sure, I’m on call nearly every weekend
but I don’t get called much as I singlehandedly
support the mainframe application I program for
and mainframes are just rock solid compared to
the other systems at the company I work for. Even
though I don’t really fit the mold for a mainframe
programmer (I’m much younger than all of my coworkers),
I’d rather be doing this than doing support for the
thousands of NT servers our company has. Those poor
desktop and server support people (a lot of interns)
have it rough. The web based mail servers on NT boxes
are always going down. They could replace a lot of
those with Linux servers but this company is in pretty
deep with the Dark Side (if you know what I mean).
I’ve seen this kind of thing in production, sort of.
At a customer, we were replacing their IBM system with an HP9000 system.
Our software was pure Unix against a relational DB. It was back office software.
However, the software that they chose to run the front (hotel management software) was designed for the IBM. They found an emulator to run the software on the HP.
So it was an interesting mixing of both worlds.
It’s also one of those little stories that should remind everyone, it’s not the OS that’s important, it’s the application.
Man, that brings it all back. I forgot about easytrieve.
Using Easytrieve Plus was my last big gig on the mainframe back in ’93.
I used it to format data extracted from an IMS database for transfer to another financial institution as well as the audit logs.
I feel old
Ah… Memeories
I remember working in a computer centre about 1974. There was a Honeywell system that stored the data entry and I remember having to manually set the registers by flipping swithes on the front of the box.
I remember cutting JCL code on punch cards and feeding them into the card reader. Spending hours sorting out stacks of cards that I had dropped.
The joys of an IBM360, then the 370, (ISPF 2 I think I used to type on the new terminal thingy – we used the redundant cards for writing notes for years).
Sometime in the early 80’s the fashion was to decentralise and I got to play with Wang V60s (can the young man emulate one of them?) and you could do something called wordprocessing on them – the beginning of the end for Mrs Nesmith’s white-out.
Forgive me I’m starting to ramble. I think I’m getting a con code of 0008. I need to take my medication.
lump
The UNISACK WTF9000/SP2. Ahh… those were the days.
Whether a centralized “mainframe” approach is appropriate or not depends on many factors.
It sounds like your employer (the State of Alaska) tends to have computing problems that are better solved by other types of systems. However, some industries still have a fairly strong need for massively centralized (and highly reliable) computing environments.
Until relatively recently, for example, I had what I have long considered to be my dream job: as an applications programmer for a major airline. The core interactive systems which are in use there are almost all mainframe based, mainly text-based transaction systems. Some run on IBM hardware, some on Unisys Clearpath hardware.