Sunday, 9 October 2011

World’s smallest mainframe!

Mainframes are so amazingly powerful and versatile, wouldn’t you like to have one in your pocket? Maybe that’s not possible (yet), but there have been many attempts over the years to shrink down the mainframe to a more manageable size.

I’m not talking about some sci fi shrink ray wielded by some fearsome purple-coloured alien, I’m talking about the use of emulation software to make one lot of hardware successfully interpret instructions designed to be used on completely different hardware – and vice versa. The mainframe programs think they are running on a mainframe and continue quite happily – totally unaware of the work being performed by the emulation software.

Fundamental Software Inc (FSI) gave us FLEX-ES, which ran on Intel chips and allowed developers to test their mainframe applications on their PCs. The PC itself ran Linux and FLEX ran under that – emulating a range of mainframe hardware devices including terminals and tape drives. Fundamental also sold hardware allowing real mainframe peripherals to connect to PCs.

In 2000 a company called T3 launched the tServer based on FLEX-ES.

UMX Technologies also offered Intel server emulation – using UMX’s Virtual Mainframe software. The company offered Windows compatibility as well.

Then there was Hercules, an Open Source software implementation of  mainframe architectures. Hercules runs under Linux, Windows, Solaris, FreeBSD, and Mac OSX. Hercules was created by Roger Bowler and was maintained by Jay Maynard. Jan Jaeger designed and implemented many of the advanced features of Hercules, including dynamic reconfiguration, integrated console, interpretive execution and z/Architecture support – according to their Web site. IBM stopped licencing its operating systems for Hercules systems, so users were left with running older public domain versions of IBM operating systems or illegally running newer versions.

Platform Solutions Inc (PSI) developed Open Mainframe servers, Open Systems servers, and NEC D-Series storage arrays. The company’s System64 product line consolidated z/OS, Windows, and Linux operating systems in one secure operating environment based on Intel Itanium 2 processor technology. At the time, Platform Solutions had a strategic partnership with T3 Technologies. In 2008, IBM took them over.

Sim390 was an application that ran under Windows and emulated a subset of the ESA/390 mainframe architecture. The emulator supported most TCP/IP operations (via socket calls using an emulated IUCV interface), and contained a Telnet 3270 (tn3270) server for remote log-in (with IP address filtering), as well as local 3270 sessions. It was possible to run it on a very small machine, such as a Pentium 75MHz with 16MB memory. So says the Sim 390 Mainframe Emulator home page.

But now you don’t need to worry about litigation, old Web sites (and older emulators), or potentially dodgy bits of software. You can have the IBM System z Personal Development Tool (zPDT), which enables a virtual System z architecture environment on x86 and x86-compatible platforms.

The IBM zPDT consists of software that is authenticated and enabled by a USB hardware key, loaded on to the Intel and Intel-compatible platform, running Linux. The zPDT comes with one, two, or three virtual engines, which can be defined as System z general-purpose processors, System z Integrated Information Processors (zIIPs), System z Application Assist Processors (zAAPs), System z Integrated Facility for Linux (IFL), and Integrated Coupling Facility (ICF).

As well as the current IBM operating systems and software, it also supports a variety of real and emulated hardware devices such as disks, tapes, printers, card readers,etc. System z customers, service providers, business partners, and ISVs can get the simpler version as part of the Rational Developer for System z Unit Test (RDz-UT) offer.

So now you can get your hands on a very small mainframe.

1 comment:

Christopher said...

Great post; ITC is the source for zPDT;