Absolutely incorrect. Some mainframe operating systems (at least VM and VSE) have been handling the time change without an IPL for a number of years (VSE 2 and VM at least 5). Yes, certain subsystems that are sensitive to the time change (CICS and DB2) need to be quiesced, but an IPL is no longer mandatory.
It is conceivable to purchase a mainframe class machine for hobbyist use. Grant it, it would be a pretty expensive hobby. Used machines are very plentiful on the market, but hardly practical for use in your basement or den. IBM has the P/390, which is a Mainframe class processor in a server. They probably start at around $10000-$20000, not including M/F software. There is a company that sell emulation software that will turn your Intel box into a mainframe. These products get very respectable performance, even compared to todays mainframe class machines. This obviously depends upon how many Mhz you throw at it. The product is called Flex/ES.
Don't let the 80 column view of the world be a deterrent. The one thing that mainframes have stressed in the past 30+ years is upward compatibility. Programs that were written that long ago can still run today, essentially unaltered (I know because we do it). Mainframes don't do I/O 80 bytes at a time, as a matter of fact real card reader/punch devices are about as rare today as 5-1/4 inch floppies drives on your PC. It is all about compatibility.
That's interesting. The marketing hype is that OS/390 is the most stable operating system that IBM develops. I run a VM/VSE shop and our system is very very stable, so stable that we have even cut out the typical therapeutic IPL. We can be up for weeks at a time.
Yes. At first it was called AIX/370. It evolved into AIX/ESA to support more real storage and provide some of the benefits that ESA mode allows. It was discontinued a number of years ago, Perhaps to free up development dollars for USS.
I'm a VM and VSE systems programmer, VSE is not necessarily unintuitive, it just takes a little getting used to. It is certainly no more unintuitive than *NIX.
SMP is NOT an intel thing. IBM's been doing SMP on Mainframes in various forms long before Windows was a twinkle in Bill Gates' eye. You think clustering is new, OS/390 can cluster up to 32 machines, each with up to 1600 MIPS each. Now that's POWER.
That is not entirely true. Banks and Insurance Companies are certainly the largest customers, but far from the only ones. There are plenty of large and medium size companies that are mainframe based and are also not banks nor insurance companies.
Mainframe hardware is not so specialized anymore. There are a number of companies that sell emulation software that will run mainframe operating systems and ancillary software off the shelf on a PC or large server of YOUR choice. The line dividing mainframe and file server is blurring rapidly.
The benefit to mainframe hardware is the dizzying speed of the I/O bus. Where your typical PC server has one bus, a mainframe can have dozens or hundreds. I/O rates are now measured in tens of thousands per second. Not to mention 32GB of central memory in the largest models.
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Absolutely incorrect. Some mainframe operating systems (at least VM and VSE) have been handling the time change without an IPL for a number of years (VSE 2 and VM at least 5). Yes, certain subsystems that are sensitive to the time change (CICS and DB2) need to be quiesced, but an IPL is no longer mandatory.
It is conceivable to purchase a mainframe class machine for hobbyist use. Grant it, it would be a pretty expensive hobby. Used machines are very plentiful on the market, but hardly practical for use in your basement or den. IBM has the P/390, which is a Mainframe class processor in a server. They probably start at around $10000-$20000, not including M/F software. There is a company that sell emulation software that will turn your Intel box into a mainframe. These products get very respectable performance, even compared to todays mainframe class machines. This obviously depends upon how many Mhz you throw at it. The product is called Flex/ES.
Don't let the 80 column view of the world be a deterrent. The one thing that mainframes have stressed in the past 30+ years is upward compatibility. Programs that were written that long ago can still run today, essentially unaltered (I know because we do it). Mainframes don't do I/O 80 bytes at a time, as a matter of fact real card reader/punch devices are about as rare today as 5-1/4 inch floppies drives on your PC. It is all about compatibility.
ASCII through and through. Except when it comes to displaying information on a 3270 style terminal, in the case of IPL, etc.
That's interesting. The marketing hype is that OS/390 is the most stable operating system that IBM develops. I run a VM/VSE shop and our system is very very stable, so stable that we have even cut out the typical therapeutic IPL. We can be up for weeks at a time.
Yes. At first it was called AIX/370. It evolved into AIX/ESA to support more real storage and provide some of the benefits that ESA mode allows.
It was discontinued a number of years ago, Perhaps to free up development dollars for USS.
I'm a VM and VSE systems programmer, VSE is not necessarily unintuitive, it just takes a little getting used to. It is certainly no more unintuitive than *NIX.
SMP is NOT an intel thing. IBM's been doing SMP on Mainframes in various forms long before Windows was a twinkle in Bill Gates' eye. You think clustering is new, OS/390 can cluster up to 32 machines, each with up to 1600 MIPS each. Now that's POWER.
That is not entirely true. Banks and Insurance Companies are certainly the largest customers, but far from the only ones. There are plenty of large and medium size companies that are mainframe based and are also not banks nor insurance companies.
Mainframe hardware is not so specialized anymore. There are a number of companies that sell emulation software that will run mainframe operating systems and ancillary software off the shelf on a PC or large server of YOUR choice. The line dividing mainframe and file server is blurring rapidly.
The benefit to mainframe hardware is the dizzying speed of the I/O bus. Where your typical PC server has one bus, a mainframe can have dozens or hundreds. I/O rates are now measured in tens of thousands per second. Not to mention 32GB of central memory in the largest models.
I can't possibly believe that USS would be replaced. It is an integral part of OS/390, whereas Linux/390 would be a standalone operating system.