S/390 Mainframes
for
experimentors, home users, and small businesses
by Cory Hamasaki

The practical home mainframe.

I have two IBM mainframes running in my living room.

The first is a 1984 vintage IBM PC/XT with a 30 meg RLL disk, monochrome video card.  It has the IBM XT/370 cardset in it.  In 1984, this set up  cost over $10,000.

The XT/370 is a two board set. The CPU board includes 2 Motorola 68000  32 bit CPU's running S/370 microcode and an 8087 recoded to execute IBM  S/370 floating point instructions. About .1-.5 MIPS depending on workload.

The memory board includes 512K of memory.  (IBM S/390 Engineering reports that this memory had a manufacturing defect and an unacceptable failure rate. To date, I have not experienced a failure.)

PC/CMS, a customized version of VM/370-CMS, runs this machine.   The boardset included a 5.25 floppies containing additional microcode for the machine.  These are called the characterization or personality files.

My XT/370 is very much like the S/360-50 that I first worked on in 1969.  The S/360-50 had 512K, 29 Meg 2314 disks and ran MVT 21.8.

The XT/370 and AT/370 only ran PC/CMS.

The second machine is a 1995 Fundamental Software Inc. Flex prototype.  The Flex is a software emulation of S/370-390.  I have the non-ESA  version.  It runs MVS/370 3.8.  The system is on two emulated 3350's.

The Flex prototype is much faster than the IBM  XT/370.  Both machines are suitable for software development on S/370,  assemblies, compiles, etc.  The Flex prototype delivers 2-5 MIPS  depending on speed and number of Pentium CPUs.  I have a single P90 engine.

A high end Flex running on multiple XEONs is very similar to the faster multi-CPU S/370s of the mid 1980's, 4381's, 3084's, and 3090's.

Other alternatives - Unless specified, these have no value on the used  market.  If you're a seller, don't expect to receive more than a nominal bid.  If you're a buyer, offer $100-500.

The AT/370- 1985/6, stronger IO subsystem than the XT/370, faster disks  but similar CPU performance and software support.  The AT/370 requires a different version of PC/CMS than the XT/370.  The software is bound to  the PC/DOS FAT file structure.  For a while, these were available on the  surplus market for $35-50.  I have one but it's not for sale.

The 4300 series - In the early 1980s, I worked on a 4341 model group II. An S/370 the size of a large chest freezer.  IBM said this machine used office environmentals.  It did not require false floor or 3-phase  power.  The bad news is, this machine delivers fewer MIPS than the 1995  Flex and uses a lot of electricity.  The 4300 is not a home machine.

The 4381 was the top of the line.  There was a two-CPU version that ran  XA.  I've seen it, it's huge.

If anyone is running a 4300 series machine and expects to continue to do so for more than a few months, please contact Fundamental  Software.  They can replace your machine for a big savings in power,  maintenance, and give you more MIPS.  If you have a 308x, 3090, ES9000,  the same applies.

The 4301 - ??

The 9370 - This is a rack-mount, departmental server. Non-ESA. It had  its own periperals but could use standard parallel channel peripherals too. Better on power than the 4341 but still not something you'd run 7x24. Late 1980's

By rack-mount, I don't mean it mounted in a rack.  I mean, it was a  rack.

The ES9000/9221 Rack mount - Looks like a 9370 upgrade.  ESA, ESCON,  fast. Early 1990's.  5-10 MIPS.

The P/370 - Non ESA version.  A upgrade of the XT/370. About 2 MIPS,  Ran in IBM microchannel bus machines. Ran all non-ESA operating systems, the first true IBM desktop mainframe. Available parallel (copper) channel card.  Estimated 2001 used market value, $1,000.

The P/390 - ESA version.  Mid 1990s vintage, 2-4 MIPS, PCI slot.  Estimated 2001 used market, $5,000.

The P/390e - eCommerce, enterprise, or web server P/390, ESA, Internal  DASD. ESCON and parallel channels available.  7.4 MIPS. This is a  desktop machine in a black case. Sold through IBM S/390 Devcon for about $18,000 or $500/month. Estimated 2001 used market, $5-10,000, depending on channel options.

The H/30 or P/30 - a two drawer filing cabinate, about 60 MIPS, ESA, ESCON,  internal DASD, OSA-2. I believe it has a variant of the 9672 CMOS CPU in it.  IBM S/390 Devcon gets $2,000/month for these on lease-purchase, make it more than $50,000 on the used market.

The Russian Option the UMX

Date: Mon, 11 Dec 2000 09:33:02 +0300
From: "Paul Truscott" 
Subject: Re: UMX Virual Mainframe

I have had some dialog with the folks at UMX.

UMX Solo (High-end Notebook version; 5MIPS) 10,000 EURO
UMX Entry Server version (8MIPS): 30,000 EURO
UMX Power Server version (20-MIPS): 50,000 EURO
(NB: 60 MIPS is now being benchmarked)

Unlike FLEX-ES, you do not need to send the machine to the vendor to have the product installed.

According to UMX, the procedure is very simple: (I quote)
"Assemble the hardware yourself or ask a business partner to do that for you
Install Windows 2000 or NT4.0
Install our UMX/VMF  and configure it
Install OS390 (basically unzip the CD's and move them to the right directory, configure and IPL!)"

I've also loaded the whitepaper into the files area, although I must state that I have not read it to see if I could do this or not. I am sure one person in particular will have something to say on that!

I must say that, this is a very attractive commercial offering. The one stumbling block remains IBM's ESL pricing. Sorry, but 32K on top of a minimum of 10,000 Euro's is still too much. I can get a lot of INTEL & Linux for that!

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