Ok, as per my understanding, you are asking about the motivation.
Well, it is pretty much the same as for developing the Hercules.
First, it would be a fun to run the system on a personal laptop. It would
provide much more freedom for experimenting etc. So, for me it is just a
technical challenge.
Second, I think it could be useful for some shops . I was surprised finding
how many companies are using Hercules nowadays.
For many shops, upgrading to a new mainframe version is not an option. Their
15-20+ y.o. software has a chance to continue its life by running on a
docker packed Hercules. Otherwise, it would be thrown to the rubbish bin.
So, I think if such the emulator be available for IBM i, it would be on a
huge demand.
Cheers,
Vlad.
-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxxxxxxxx] On Behalf Of
Patrik Schindler
Sent: Friday, May 29, 2020 8:39 AM
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxxxxxxxx>
Subject: Re: OS/400 on mambo emulator
Hello Vlad,
Am 28.05.2020 um 17:51 schrieb Vlad Korge <vladkorge@xxxxxxxxxx>:
As per my understanding, a nowadays IBM i is running on exactly the same
hardware as AIX or Linux called IBM Power Systems.
Yes, and they've been marketed with different price tags. I bet there's
something like a "IBM i/Other" switch somewhere. Not necessarily a physical
switch, though. But do you really know how that hardware is controlled by
firmware? These boxes are architecturally not just like an x86 server with a
different CPU type (POWER). See Yvan's comment about Open Firmware vs. IBM
i.
You're not the first one and will not be the last one trying to get OS/400
and it's successors run on standard x86 hardware with some means of
emulation. Why is emulation so desirable, despite the apparent huge effort
needed to get it done? (And the high risk being sued to death by IBMs
lawyers.) Comparing to Hercules (emulating the S/3x0 and z-Series of IBM
hardware), is it portability (taking my mainframe with me on my notebook)?
Is it about not requiring extra hardware (with it's own needs of space and
power to provide noise and more or less heat, and sometimes needs repair)?
I'm content with my very own, very old hardware, converting around 100W
electrical power into heat and noise. This old hardware is interesting in
itself (to me), because of reasons Yvan already described. I'd summarise
them as "mini-mainframe like". I can't take it with me easily, but I don't
need to: I can use VPN to get access to my home net from
anywhere-with-internet-connection. (Same with Hercules, I don't need it to
be "portable", it runs on a Linux server in the basement, providing mostly
storage services, and I also can log in from where I want to that TK4-.) All
that old stuff relied on Terminals. No need to be close to the hardware, no
need to take an emulated hardware with you.
Think twice: What's your benefit from emulation?
The more serious problem is that you almost always need license keys to
prevent the OS force you into a complete reinstall after 70 days *if* you
reboot after then. And even without reboot, some programs will cease to
start without license keys. This problem will not be solved by emulation.
Emulation means, you'll need to fake an environment which is
indistinguishable by IBM i from a LPAR. You'll have a lot of fun finding out
how everything is supposed to work together, because there's no Low Level
Documentation available outside of IBM. As others have put it: Just don't
expect to start the Mambo binary, point it to the proper I_BASE Image file
and everything will work just out of the box. It's a *lot* more than
struggling with the use of Mambo itself.
:wq! PoC
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