
Buying an IBM Mainframe - nollbit
https://blog.mainframe.dev/2019/05/buying-ibm-mainframe.html
======
kev009
It's a lot cheaper in to do this in the US and with a long term view, my total
outlay was under $3000 for a z800, z114, ds6800 all in with transportation. I
also temporarily had two DS8870s but resold them because they were worth a lot
more than I paid and I will pick up another for cheaper over the course of
this year. Both of my frames have HMCs, the z114 was even IBM banded and "MSQ"
maintenance service qualified which means they'd come and set it back up for
some not-too-outrageous monthly fee if it were in production use.

The z800/z890 are probably optimal for hobby use even though they are old
because they have modest power requirements and are relatively light and not
too wide like the z114 which is absolutely massive.

Actually a P/390 (MCA or PCI card), or Multiprise 3000 (deskside hybrid
CMOS/PC server thing) would be even easier but those are very very old 31-bit
systems at this point. (I also have a R/390 setup and can comment on that if
desired)

Now that said, this requires A LOT of dedication to get right. You need to
understand at minimum shipping/transport issues, as well as electrical
requirements and installation (or be willing to consult someone that can
advise you on phase and conversion if necessary).

After that, you definitely need an HMC (a PC used to do things like load the
OS) or at least a recovery disk and a lot of patience to set that up in
emulation or on other hardware.

And then, you need a FICON (or older ESCON) capable array. Connor Krukosky
goes into detail about what it's like without that, and you are extremely
limited (basically Linux) in what you can do without FICON. A ds6800 is the
easiest way to do that because it is a small rackmount unit, but they are also
in demand for that reason. DS8ks are quite cheap all things considered, but
serious iron like the frame itself.

And then finally you need some OS media which is also non-trivial to get
(although there is or was some "out there" on file sharing).

I am willing to help anyone interested in this kind of thing for fun and
preservation of incredible technology and history.

~~~
bluecmd
Hi kev! Thanks for your comments, you are 100% right. Yes, living in the
states make this hobby waaay easier. The surplus auctions help as well, having
various goverments with various languages going in Europe does not make it as
easy :-).

Was $3000 your outlay for the system + the DS6800? Or just the shipping? That
is a great find in that case!

I just want to correct a small thing: You need SEs (the frame mounted
laptops), you do not actually need an HMC as far as I know. Do you have any
information that tells another story? If so I will update the article.

Thanks again!

~~~
rbanffy
> Yes, living in the states make this hobby waaay easier.

It's unbelievable how thoroughly Europeans recycle their old computers. I
can't find anything.

~~~
rbanffy
BTW, any other European retro-computing enthusiasts that see this, feel free
to exchange your thoughts on how to find the machines that escaped the
relentless push towards green tech.

------
cominous
Is it just for the fun or is there actually a legit use case for having a
mainframe at home apart from accelerating climate change?

~~~
walkingolof
I think its a great career niche to be fluent in everything Mainframe, they
are still used in critical places and will be for the foreseeable future and
they are largely overlooked as a opportunity.

So if you want to work in this niche, having your own Mainframe will greatly
speed up learning the system.

It probably also looks awesome when you market yourself.

So all in all, 25k USD for kickstarting a potentially very profitable career
sounds like a bargain ....

~~~
icedchai
If you just want to learn the software, you can set up Hercules mainframe
emulator for free. Finding an image of z/OS is left as an exercise to the
reader, but won't take you long.

[http://www.hercules-390.org/](http://www.hercules-390.org/)

------
jandrese
My interest in doing this (my wife would kill me anyway) kind of evaporated
when in almost every paragraph he hit on licensing issues you might have. What
a headache for someone who just wants to tinker on the hardware and maybe buy
a few parts off ebay for the full experience. I have no doubt software
updates, documentation, and everything is locked behind some portal that
requires you to have a stupidly expensive support contract to access.

~~~
jschwartzi
My second thought about this was "no wonder IBM is largely dead outside of
stodgy corporate IT. Nobody can actually learn to use it without dropping
$100,000+ on equipment."

~~~
pickle-wizard
Back when I was at IBM one of the hats I wore was AS/400 administrator and
programmer.

I miss working with it and would like to buy one for my home lab, but the
licensing is a killer. I find used ones on the market, but they usually don't
include the license keys or media, and without a support contract can't get
them.

I really wish IBM had a hobbyist program. I wouldn't expect it be free, but I
wouldn't mind paying a small yearly fee.

~~~
msla
The irony is that IBM had one of the first Open Source communities: SHARE,
dating back to 1955, shared software up to and including a whole OS, SOS
(SHARE Operating System), well before Unix or home computers even existed.

[https://en.wikipedia.org/wiki/SHARE_(computing)](https://en.wikipedia.org/wiki/SHARE_\(computing\))

------
iuguy
It's not the same, but if you'd like to have a go at mainframe technologies
you can do it with a Pi Zero:

[https://www.rs-online.com/designspark/my-raspberry-pi-
thinks...](https://www.rs-online.com/designspark/my-raspberry-pi-thinks-it-s-
a-mainframe)

Once you have the basic emulator setup working, check out the Turnkey system
below. It's MVS 3.8 so not current Z/OS. If you google around for z/os ADCD,
you might find an actual Z/OS CD to try next.

[http://wotho.ethz.ch/tk4-/](http://wotho.ethz.ch/tk4-/)

~~~
tyingq
_" MVS 3.8 so not current Z/OS."_

Bit of an understatement, MVS 3.8j was released in 1981.

~~~
bigato
You'd be amazed at how little the underlying ecosystem has changed over the
decades. Because it basically keeps compatibility forever, software that was
written in the 60's can still run on modern machines. Because of this,
learning using 80's software in the mainframe world is not too bad. For
example, I keep a book on MVS on my desk from the 80's for reference, and most
of the time it suffices for what I need to consult.

~~~
tyingq
At a high level, I suppose, but for example...3.8j is 24 bit versus the
current z/os 64 bit.

~~~
bluecmd
Indeed, the 16 MiB virtual memory space is kind of limiting for anything
remotely modern :-).

~~~
bigato
It teaches efficiency to learn the basics on such a system, something modern
programmers are often lacking

------
cosmodisk
This is what you do when you don't get PlayStation when you are a kid...

------
OldManAndTheCpp
Dissatisfied with the performance of a home raspi? Buy a mainframe!

------
jasonhansel
My current side project idea: build a modern programming language with a nice
syntax that compiles (transpiles?) to mainframe COBOL, mostly to get mainframe
programmers to stop writing code in SHOUTING ALL CAPS.

~~~
jasonhansel
Note: is anyone interested in using something like this? If so, let me know!
I'm curious as to how I can make it useful for people in the field.

~~~
danpalmer
As I understand it, the field is going in the other direction, namely JVM/CLR
COBOL. This means that companies can migrate their COBOL codebases to
“commodity hardware”, save on mainframe costs, and then progressively refactor
into Java/.NET replacing bits of COBOL piecemeal.

The main company I’ve heard of doing this is MicroFocus, they have all the dev
tooling for it for the major IDEs, compilers, etc.

One of the main things that complicates the problem, again as I understand it,
is that there is no official COBOL spec. There are several versions from
several vendors, but compilers have to account for mainframe hardware bugs, so
there are many different targets that have to be supported. Most companies
want a different, specific, set of compiler features.

~~~
jasonhansel
Hmm. I'm interested in making a compile-to-COBOL language only because that
way a company could incrementally migrate an old COBOL codebase to the new
language. In other words, the new code (which compiles to COBOL) and the old
code (written in COBOL) would be fully interoperable, sharing the same data
types, calling conventions, etc.

~~~
danpalmer
Yeah, and this makes sense, but there are multiple problems with COBOL on
mainframes – the COBOL, and the mainframes.

COBOL and mainframes have quite a different programming and system
administration model to what we expect with servers. Lots of concepts are
quite different, built up from a world of mainframes and terminals, tapes,
batch processing, etc. Concepts like users, operating systems, files,
networking, parallelism, programs, databases, are all quite different, and all
of these differences cause companies problems in training users, and creating
nice new software that works in ways people expect now.

Creating a, for example, JavaScript to COBOL compiler is probably not fully
possible. You may be able to transliterate it, but you would essentially be
writing a COBOL program in JavaScript syntax – not using Node libraries and
writing React components. This reduces many of the benefits.

The alternate approach is that you take your COBOL and compile it to work in
the JVM. You get a JAR out that you can run on your regular servers that are
already running your other JVM software. There is probably a significant
runtime built into that by the compiler that translates some mainframe
concepts into modern concepts, but that's fine because you haven't had to
rework your COBOL. Then, you can progressively pull out modules, rewrite in
Java, and reference those from the old COBOL code. You don't need lots of
training in mainframe concepts, you don't need to spend millions of dollars a
year on your mainframe, and you can write new code in Java.

The US Department of Defence have taken this approach one step further, and
are actually writing a compiler from COBOL to Java. It's not fully automated,
but with not too many developer-hours, they can turn significant chunks of
COBOL into reasonably good quality Java, over the course of several stages.

Your idea is a good one, and worth experimenting with maybe, but I think the
best approach for the migration away from COBOL for large businesses (and only
large businesses use it) is the other way around.

------
new4thaccount
Now this is an expensive hobby. I spent this on my last car (a necessity where
I live).

It was a great read though and I'd probably buy one as well if I had the
money, time, and space. They seem like underrated machines.

------
altmind
Are there any sucess virtualizing z/OS on x86_64? This mainframe is quite
anemic even by modern desktop standarts.

~~~
hsnewman
If you do go with virtualization, in addition to Hercules, you can possibly
find a copy of the ADCD, which is a full release of the OS on the cheap.

~~~
tyingq
_" which is a full release of the OS on the cheap"_

It's a $900/year subscription if you go the legit route, and not "approved" to
use with Hercules. You're supposed to pay ~$4k for zPDT to be fully legit.
Thus, most hobbyist use is pirated torrents of ADCD on Hercules.

------
purplezooey
1700 watts, all the time. Yikes.

~~~
glogla
That's pretty solid space heater.

~~~
quickthrower2
Very inefficient though. But solid!

~~~
sliken
Actually it's 100% efficient in terms of converting electricity into heat.
Anything that consumes electricity is near 100% efficient at generating heat.
If you tried really hard you could build a very efficient laser and send heat
outside the room, so not 100% would end up in the room. Even then the majority
of heat will be dissipated in the room.

~~~
quickthrower2
It’s 100% efficient, but you can do better than the 100% without breaking
thermodynamic Laws with a heat pump.

~~~
sliken
Right, but it was being compared to a space heater, not a heat pump.

Not to mention heat pumps require somewhere to pump to/from, you can't just
put one in your basement, plug it into the wall, and heat up the basement.
Also heat pumps work best with mild differences, like say 40F inside and 60F
inside if you want to heat.

Heat pumps reduce to space heater efficiency if it's sub-zero Fahrenheit
outside I believe.

~~~
quickthrower2
Sub Zero F is seriously cold! But for most climates there is some advantage.
40F is pretty cold. Take somewhere not particularly hot like London - most of
the year it will be warmer than that.

Although in the UK most people use gas to heat their homes, because its
cheaper. I worked out once that gas and heat pumps cost the same in the end
for the amount of energy. Although what I love about heat pumps is how quick
they get a place warm compared to radiators.

Granted heat pumps need installation, or you can probably run a tube out the
window with one of those adapters.

It's a silly hypothetical discussion, because for the price of this mainframe
you could get a heat pump and a set of solar panels and a battery storage, and
have some money left over for some Hawaiian shirts to wear once you've heated
the place up.

For financial efficiency (environment be damned) a set of crypto miners would
be better than either the mainframe or the heat pump.

------
callesgg
Is there something that makes these ibm mainframes special like some feature?

Are they simply like a big computer?

~~~
floatboth
From what I've heard, redundancy and scalability in a single machine (like,
you can hot-swap CPUs on a running machine and have lots of redundant RAM,
etc.) and being able to run an OS with backwards compatibility all the way to
the fscking 1960s or whatever.

That OS is… something: [https://medium.com/@bellmar/hello-world-on-z-
os-a0ef31c1e87f](https://medium.com/@bellmar/hello-world-on-z-os-a0ef31c1e87f)

------
unixhero
This was an insanely cool read.

~~~
bluecmd
Thanks! Glad you enjoyed it :-)

------
pickle-wizard
I cringed when he said he bought a DS6800. When I worked at IBM we had about
20 of them and they were shit. Always broke and getting into weird states. No
way I'd run one with a support contract.

~~~
kev009
My understanding is a team ported the ESS "Shark" code from AIX to the little
Linux 2.x embedded controllers. It looked like Adaptec OEM hardware when I
tore mine apart. I can see how that would go poorly versus the proper cabinet
sized arrays. They are definitely good enough for home use but I agree not
what you want any production workload on. I heard from a 3rd party support
company there is some part that is prone to failure but I cannot recall what
it was.

~~~
pickle-wizard
Yeah I found the root linux password online. There was more than once I had to
SSH in and fix the SLIP connection between the controllers when they went into
a brain split.

If I recall correctly they were running SuSE Linux with Websphere App for
management and DB2 storing all of the configuration information.

I hadn't heard they traced their linage back to the shark. That surprises me a
bit because we had several of those and they were very reliable. Though
thinking about it that makes sense.

Hopefully the later software fixed the reliability problems. I got rid of all
of ours in about 2010 or so. Replaced them DS5000 on the Open Systems side
(which had their own set of problems), and DS8000s on the Mainframe side. The
DS8000 was pretty rock solid.

------
wglb
And for some security bits, check out
[https://www.youtube.com/playlist?list=PLBVy6TfEpKmGdX1OE_xjK...](https://www.youtube.com/playlist?list=PLBVy6TfEpKmGdX1OE_xjK0GKGjSLwxVn_)
which as also some general mainframe access info. His twitter feed is
[https://twitter.com/mainframed767?ref_src=twsrc%5Egoogle%7Ct...](https://twitter.com/mainframed767?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Eauthor)

------
unixhero
Just wondering:

What kind of problems do you hope to solve? Are there anything in particular
you will use it for?

------
Causality1
He dropped over $23,000 on a mainframe just to "play with and learn how it
works"?

Finally he can run a personal Minecraft server.

~~~
bluecmd
Would you have liked the project more if the price was not disclosed?

~~~
Causality1
Oh I love the project. I'm just in awe of spending that much money for
something you don't have a clear and present need for.

~~~
closeparen
In my parents' generation, it would have been a project car.

