My Personal Mainframe?

I'm seriously thinking about getting a mainframe at home.

Here's how it might work, using U.S. prices. Let's start with the machine. According to a recent IBM-MAIN post, a small used z800 is now about $30,000, so it's like buying a typical new car. The new z9 BC is a much better choice for business purchases, especially given its lower running costs in real business use, but the z800 would make an excellent home mainframe for my purposes. The z800 happens to run on single phase electricity, so that's a major plus for home use. A z800's electricity consumption is reasonable. It's a full 64-bit system, so it runs all the latest and greatest software. And it has at least 8 GB of memory standard, so there's plenty of room for the most demanding home workloads that I would run.

I'd have to add disk and tape. One older tape drive, such as a 3490, would do just fine for my purposes (software installation). Anybody know where I'd find the disk?

Then there's software. I'd like to run z/OS as well as Linux. The z800 is eligible for z/OS.e (the e-business flavor of z/OS), which is a good fit for my use. I would only need 3 MSUs (about 20 MIPS), the minimum capacity, and I would softcap my LPARs and send in my monthly subcapacity reports since the smallest z800 has at least 40 MIPS of capacity. I configured z/OS.e with the C/C++ compiler, the Security Server (RACF), RMF, and a couple other bits and ended up with a monthly price of $126. That's a minimum configuration that might not be suitable for many businesses, but for my home mainframe it'll do just fine. For about $1,500 per year I can get real z/OS.e, so I'm impressed.

I can download and legally run Linux since it's GPL open source. Choosing a distribution is another question. I could choose Debian Linux for my home system, and I could make a voluntary contribution to the Debian community to support their efforts. Or I could contribute Linux code enhancements back to the community, as I've already done recently for a USB driver. Or both. The standard Novell and Red Hat support agreements (about $15,000 per year per mainframe CP or IFL) don't make sense for my home mainframe, but businesses need different support than I would.

I'd like to run WebSphere Application Server for z/OS. At 3 MSUs that's somewhere around $3,000 for the first year (including subscription and support) then a few hundred dollars per additional year. That's not much money for the world's finest enterprise J2EE server, so I can get a real transaction manager for my z/OS.e home system. There are other Linux and z/OS options, but that one looks best for me.

I'm not sure I need a relational database. DB2 for z/OS is awfully nice, but at 3 MSUs it might still bust my home mainframe budget. I'll stick with VSAM, Linux flat files, and Linux databases like PostgreSQL and MySQL for the time being. (Or I could try to recompile those databases with my C/C++ z/OS.e compiler.) I can access VSAM and Linux relational databases from WebSphere Application Server for z/OS quite easily. Communications between z/OS.e and Linux will be through HiperSockets.

Nearly all businesses opt for full hardware maintenance, and that's prudent. My home mainframe is different, though, so I'll probably rely on any warranty I get with my z800 purchase plus as-needed hardware repair. With a 40+ year MTBF on IBM mainframe processors I'll have to roll the dice for my home system.

Perhaps I could rent out time on my home mainframe to hobbyists, developers, and even small businesses. Basically I could go into the mainframe service bureau business, at least to a limited degree. Over time I could upgrade to that z9 BC, license DB2 for z/OS, add more and faster storage, etc.

Did I miss anything? Would anyone like to ship me their z800 to give me a head start?

by Timothy Sipples November 15, 2006


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Or you can just buy the zOS and emulate a mainframe using Hercules. Not sure if that is legal but I guess it should be ok for home use.

Posted by: Manish | Nov 15, 2006 3:41:01 AM

And alongside WebSphere, you should soon be able to use PHP for your application development language! (,1895,2005973,00.asp)

Posted by: Bill Seubert | Nov 15, 2006 12:31:38 PM

Timothy, why worry about the cost of z/OS.e? If you have a z800 and are using it to develop z/OS software, why not just join the IBM PWD program and get a license for z/OS, plus all of the development tools you need for no charge? While the PWD program is geared towards developers that have the Flex-ES systems, I don't think there is anything in the terms and conditions of that program that would preclude your membership (with all of it's benefits) if you were using a slightly bigger (and "real") IBM mainframe as your development system.

If I am mistaken in this, I am sure somebody from the IBM PWD program can correct it.

On the other hand, a z800 weighs quit a bit, and will certainly cause your electric bill to go up, not to mention your a/c usage (depending on where you live, of course). And there is the issue of DASD....the z800 comes with no DASD, so you'll need some sort of 3390, Shark, DS8000, etc. That will increase the cost and power/space requirements too.


Posted by: Dave Jones | Nov 15, 2006 12:38:58 PM

These kinds of creative musings should motivate more fundamental questions.

Why hasn't IBM come out yet with a two engine(Z9 gen) mainframe in an ATX or standard server motherboard packaging and 110V single phase power, just like we fondly remember with the multiprise 3000, P/390, and Integrated Server?

Seems to me like this would inspire much interest. Or, perhaps update the P/390 card to a single Z9 engine, and make a new P/390 based on that with Linux as the platform for device managers and emulated I/O.

There aren't any reasonably priced developer hardware options now. Hope we hear something soon.

Posted by: emes | Nov 15, 2006 12:46:22 PM

it would be very intelligent for ibm to send you one. i will start agitating in the back channel. i also think they should send one to linden labs...

Posted by: james governor | Nov 15, 2006 12:47:58 PM

The rumor mill does say something is coming in 1Q07, which is part of the reason why the Funsoft agreement was not renewed.

Anyway, Timothy has an inside edge as to getting IBM software to legally run.

I knew someone who had an IBM 4341 in his garage + associated peripherals (DASD, tape, controllers) - even paid for the local electric company to come out and run 3-phase power. He was running OS/VS1 - of course, illegally, but this was 1988.

Posted by: Ray Mullins | Nov 15, 2006 12:58:44 PM

The PWD idea is a good one, if I can restrict my use of the system to development purposes only. However, I might want to run a commercial Web site, rent time, or otherwise possibly run afoul of the PWD terms, so in this set of musings I opted for the full licenses.

There's no "inside edge" here, quite deliberately. Everything I describe is available to the general public as far as I know.

Posted by: Timothy | Nov 15, 2006 8:37:27 PM

Re: Disk, here are a couple interesting options I found:

They look fine for home use, although businesses might feel differently. I wonder if it's possible to IPL through these devices.

On the other hand, IBM Enterprise Storage Server ("Shark") equipment on the secondary market looks quite affordable. There's nothing on eBay right now, but in the recent past item # 260050446613, a 2105-E20 with 3.3 TB of disk, had a price of $4,400. There's a problem, though: a three phase power requirement. The IBM DS6000 would be perfect, especially a depreciated earlier model, but it's hard to find on the secondary market.

Posted by: Timothy | Nov 16, 2006 12:59:39 AM

You forgot ongoing power costs.... However there may be some heating benefits....

Posted by: Anthony | Nov 17, 2006 2:12:44 PM

For your Linux you might consider CentOS, a community supported enterprise OS. It's a RHEL system rebuilt from GPL source and downloadable for no charge. There is a mainframe version. No support from Redhat of course. has more info.

Posted by: John A | Nov 22, 2006 4:59:36 PM

can anybody tell me the resource from where i can get the access to mainframe systems through internet.

Posted by: ajay | Jan 20, 2007 9:42:44 AM

If you are looking for DASD with single phase power, you could try a 2105-E10 or 2105-F10. Limits the number of 8-packs you can add, but that probably isn't an issue for a home system. The IBM web site lists an IBM certified used 2105-F20, but you could probably get them to swap power supplies. The 2105-800 page specifically says that you can request a custom 2105 quote at IGF discounted prices.

Posted by: Bradley P. | Jan 27, 2007 12:53:13 AM

if you want mainframe/supercomputer access for free try:


Posted by: deus | Jan 31, 2007 9:48:14 AM

I need to have access to any mainframe with a RACF setup for development purpose. Anybody knows where I can lease some cpu time?

Posted by: John | Feb 9, 2007 8:43:46 PM

hi... i have one doubt .. can i access data in my pc's port (parallel or serial) to mainframe. & also can store one document file with my data in my disk drive and can access one more file from my disk drive.

Posted by: suresh | Jul 29, 2007 5:50:48 AM

Hi All,

I am new to Mainframe, Guys i want to learn mainframe systems and so. If anyone could you please tell me, where i can get resources like books and other materials fo free of use.

And I thank you advace for your needfull.

Thanks and Regards,

Posted by: Vinay | Aug 15, 2007 6:29:48 AM

I own a New/Old Stock, 3880 DASD, Storage Controller. The two units were purchased by the U.S. Department of Energy, for the Rocky Flats Plant. The plant was closed, before the Storage Controllers were installed. They have been in dry storage, since 1995.

I don't want to part them out. I would like to find a buyer. Any ideas?

Thank you!

Posted by: William Chapman | Sep 25, 2007 4:57:40 PM

Ever tried hercules ? :-) A really cool and free mainframe-emulator for your x86 box. Unfortunately IBM does not permit to z/VM and z/OS on that emulator.....

For me as an student, it´s not very motivating if i would like to get detailed operating-system knowledge (z/OS,z/VM) without having a good testsetup. At university we got a new mainframe from IBM for educational purposes, but it would be much cooler to test things at home or in the subway :-)

Posted by: MC | Jan 18, 2008 8:06:07 AM

Unfortunately, you'll end up with your name and phone number on the lists of BMC, CA, ASG, IBM and a thousand other vendors who want to flog you some mainframe software;
With the phone ringing all day - will you ever have a moment to use your z box

Posted by: CJ | May 21, 2008 5:08:19 PM

Hi guys,

I am looking to rent some machine time. WOuld anybody suggest a good link?

Thank you,

Posted by: Stan | Oct 9, 2008 10:54:30 AM


im looking to work on mainframe server for practice. Suggest me if anybody provide on rental basis.

[email protected]


Posted by: saikiran | Jan 26, 2011 2:57:40 AM

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