
Running a full IBM System/370 Mainframe on a Raspberry Pi Zero - lhoff
https://twitter.com/BrianRoemmele/status/1257832168455208963
======
Harvesterify
This is apparently greatly over-hyped (or a complete lie, depending on your
interpretation) :

[https://mobile.twitter.com/mainframed767/status/125801882682...](https://mobile.twitter.com/mainframed767/status/1258018826823729154)

~~~
tyingq
It's possible the original tweet poster was running a much newer mainframe OS
on his Hercules emulator, but didn't want to say it directly, since he might
get a license bill for that.

 _" 7 times faster than System/370"_ is an odd claim though. There's several
models and 19 years of upgrades.

~~~
temac
System/370 ended in the eighties I think? Maybe it is reasonable to be 7 times
faster than the fastest System/370.

~~~
rst
The fastest S/370 (pre-S/390) machine in the line was, I think, the 3090;
these were multiprocessors, but a single processor had a 69 MhZ clock rate.
Even if you assume it retired one instruction per cycle (and I'm not at all
sure it did), it wouldn't be a shock for Hercules on an RPi to manage that.

------
tyingq
Should probably be a link to the Hercules emulator, since it's the real magic
here. [http://www.hercules-390.eu/](http://www.hercules-390.eu/)

Even runs current z/OS, though there is no practical legal way to do that.

~~~
ngcc_hk
[http://wotho.ethz.ch/tk4-/](http://wotho.ethz.ch/tk4-/) just in case

How is it relates to Hercules?

~~~
tyingq
Tk4- is a custom "Hercules ready" packaging of the last version of MVS (3.8j,
24 bit, released in 1981) that you're legally allowed to use with Hercules.
And probably other nice add-ons around installation, docs, etc.

------
tw04
I find it somewhat ironic that IBM is struggling so hard to find COBOL
programmers to keep mainframe alive, but they also insist on locking down z/os
to the point that you can't get access to a terminal unless you already know
COBOL and work for an enterprise spending millions with IBM.

You want nerds to flock to your platform, you have to give them access...

~~~
kyrieeschaton
There's no problem finding "cobol programmers"; "cobol programming ability"
isn't their bottleneck. Finding someone competent to do professional software
archaeology & borderline forensics for 40K/y is their bottleneck.

~~~
cloudier
“Shortage of programmers” almost always means “we don’t want to pay full price
for programmers”.

~~~
smnrchrds
Isn't that the definition of shortage? When we say there is a shortage of X,
it means that there is X, but not enough of it to keep the prices at an
affordable level, so the prices have risen and some people who need X, want X,
and/or previously could afford X no longer can. This is true as long as there
is a _shortage_ , not an absolute _lack_ of something.

I mean, famines happened because sometimes there would be a shortage of food,
perhaps due to drought, or a sudden increase in population not matched by an
increase in food production. Prices would go through the roof. Rich people
could afford the new prices and persevered. Poor people died of hunger. But if
the poor mustered enough gold, they could go buy food like rich people did.

So my question is, do you consider famines shortages? If not, what even is a
shortage? In yes, how is labour shortage any different, except in scale?

~~~
blululu
Note that your example of a famine brings up 'shortage' before any mention of
prices. There are multiple ideas of shortage at play. At the most basic level
shortage can mean that there is not enough of a good/service for everyone to
have it at any price (food in a famine, medicine in a pandemic). Typically we
apply shortage to situations where the supply and demand curves reach some
hard stop at the edges (elasticity goes to 0). In the case of normal market
dynamics where supply and demand are both reasonably elastic then there really
are no shortages per say - just cheapskates.

------
fapjacks
I used to experiment with a Hercules MVS (my first real computer job was sysop
at an institutional datacenter with an MVS) on my eeepc on my second tour in
Iraq. Doing convoy security, of course we never had any network connection of
any kind (it being the middle of the desert and also having active RF-jammers
on our guntrucks), and there was always a long wait for the MWR computers at
whatever base we'd stopped at for the night, so we were left with only
whatever data we could pack before each mission. I spent hours and hours
hacking on that thing. It was a pretty absurd situation, but I had a lot of
fun.

~~~
zentiggr
On my last two sub deployments I bought a midrange laptop and Mandrake Linux
8.0, had a grand time installing, reinstalling, tweaking the hell out of it,
learning to handle a running *nix.

Came in handy when an onboard system based on HP-UX cut out while underway and
out of contact with fleet technical support.

~~~
kstrauser
I was on a surface (aka "target" to you) cruise, and spent all my downtime in
the medical department hacking away on an unused little laptop. This was when
MARSGRAMs were the height of fast communications, and the procedure for
sending them was to handwrite your message on a slip of paper and pass it to
the radio guys, who would then type a bunch of them into a computer hooked up
to a packet modem. That was pretty low priority for them, understandably, so
things would wait in queue for quite a while before they could get around to
doing some data entry.

I knocked up a little QBasic app that let you type in your MARSGRAM message
and then write it out to a floppy, batched alongside everyone else's messages.
Once every couple of days, we'd run that floppy to the radio guys who'd pop it
in their computer, blast out the messages, and write any replies they'd
received to it back out so you could take them back to the department and
everyone could read notes from their loved ones.

I'd have a hard time exaggerating how well this went over with everyone
involved (except maybe the MARSGRAM operators who were suddenly carrying a lot
more messages than they were before because it was so easy to send them). "Hey
Captain, I heard you say you were missing your wife. Want to send her a
message and hear a response in a couple of days instead of months?"

It worked out pretty well for me personally, too. I had a great boss at the
time who told me flat-out that I was an idiot for pretending to want to work
in medicine, when my heart was clearly elsewhere. It'd never occurred to me to
make a career out of computer stuff before then, and a short time later I was
out of the Navy and enrolled in a compsci program. Thanks for the kick in the
right direction, Ken!

~~~
jeffrallen
In 2006 on my first mission with MSF, we had a BGAN satellite terminal.
Luxury! Because in my downtime, I'd read the tech library on CDROM, which
explained how to organise a mail service with floppy disks and Landcruisers,
with a relay to Paris over HF radio via Portishead, UK..

~~~
kstrauser
That's beautiful.

------
xacky
This is the power of Moore's law. A computer that cost millions reduced to $5.
Shame we waste all the power we have now days.

~~~
rrmm
The bitcoins must be mined!

------
psim1
For a bit more fun with mainframe emulation if you're not already a mainframe
programmer, check out MUSIC/SP on the System390 emulator [1]. You can run
MUSIC/SP on Hercules also, with some limitations [2].

[1]
[http://www.canpub.com/teammpg/de/sim390/](http://www.canpub.com/teammpg/de/sim390/)

[2]
[http://www.canpub.com/teammpg/de/sim390/hercnote.txt](http://www.canpub.com/teammpg/de/sim390/hercnote.txt)

~~~
fit2rule
EDSAC[1], on BCPL[2], on raspberry Pi et al, ..

[1]
[https://www.cl.cam.ac.uk/~mr10/Edsac.html](https://www.cl.cam.ac.uk/~mr10/Edsac.html)

[2]
[https://www.cl.cam.ac.uk/~mr10/BCPL.html](https://www.cl.cam.ac.uk/~mr10/BCPL.html)

------
csdtx
I wonder how the uptime and stability is on the Pi? IBM mainframes rarely go
down and are up from setup to decommissioning.

~~~
passer_byer
Except when they do go down. Not as a result of the processor itself, but as a
result of the hiccups in the dependency chain.

In one case ours went down for a day when a backhoe hired for construction cut
a power supply line. The data center batteries designed to give time for the
desiel generator to kick-in were fine. The generator failed to start as a
result of contaminated fuel despite monthly tests.

The second time was when an employee brought their 12 year old son into the
raised floor environment. He found and pressed the haylon dump button for fire
suppression. Staff were lucky to escape without suffocation.

The employee was fired and stricter entry requirements to the raised floor
area were implemented.

~~~
hinkley
> The generator failed to start as a result of contaminated fuel despite
> monthly tests.

I don’t think this is he first time I’ve heard such a thing. I wonder if the
people running such tests know how long you have to run the generator to flush
the fuel lines? And aren’t there failure modes for ICEs - and diesel in
particular - where the engine stops working once it reaches operating
temperatures?

I had a car that would occasionally conk out due to a damaged O2 sensor (due
in turn to a crack in the manifold).

------
ipnon
IBM System/370 = $2,248,550 [0] Raspberry Pi Zero = $5 [1]

[0]
[https://www.ibm.com/ibm/history/exhibits/mainframe/mainframe...](https://www.ibm.com/ibm/history/exhibits/mainframe/mainframe_PR370.html)
[1]
[https://www.adafruit.com/category/934?src=raspberrypi](https://www.adafruit.com/category/934?src=raspberrypi)

~~~
smacktoward
That’s $2,248,550 in 1970 dollars. In today’s money, that would be more like
$15 million.

~~~
eigen
alternately, its much < $87k based on Computers, peripherals, and smart home
assistants CPI-U.

[https://www.bls.gov/cpi/tables/supplemental-
files/home.htm](https://www.bls.gov/cpi/tables/supplemental-files/home.htm)

------
ablekh
In the meantime, somewhere in the universe, people are buying mainframes ...
for personal use: [https://blog.mainframe.dev/2019/05/buying-ibm-
mainframe.html](https://blog.mainframe.dev/2019/05/buying-ibm-mainframe.html).
Go figure! :-)

------
mikewarot
I have a friend who used to work at IBM... and does Model railroading... there
could be an interesting intersection there. 8)

