Unisys Phasing Out Decades-Old Mainframe Processor For x86

angry tapir writes: Unisys is phasing out its decades-old mainframe processor. The chip is used in some of Unisys' ClearPath flagship mainframes, but the company is moving to Intel's x86 chips in Libra and Dorado servers in the ClearPath line. The aging CMOS chip will be "sunsetted" in Libra servers by the end of August and in the Dorado line by the end of 2015. Dorado 880E and 890E mainframes will use the CMOS chip until the servers are phased out, which is set to happen by the end of 2015.

Comments

Half a century

[Animats]

That's over half a century of the UNIVAC 36-bit architecture, going back to the UNIVAC 1107. The operating system in use today, originally EXEC 8, later OS 1100, later OS 2200, first ran on the UNIVAC 1108 in 1966.

Some programs from the 1970s will still run today. Some from that era are still being maintained and distributed.

Re:Half a century

[Anonymous Coward]

Yep, X86 is definitely taking over. http://regmedia.co.uk/2011/01/05/nvidia-arm-x86-shipments.gif

Re:Half a century

[Guy Harris]

Uh, I thought this was the descendant of Burroughs B5000? You know, the computer that Alan Kay tells everyone to take a look at to understand how silly today's architectures look in comparison.

It's both the descendants of the 36-bit Univac 1108 and the 48-bit-plus-tags Burroughs 6500 (very much like, but not compatible with, the B5000).

Re:Half a century

[Required Snark]

The Burroughs part is a tagged memory architecture. There is no assembler, a variant of ALGOL is the system programming language. It's a hardware stack machine. Each memory word has tag bits that identify what kind of information is stored. Memory addressing is through segments, which do hardware bounds checking. Check out http://en.wikipedia.org/wiki/Burroughs_large_systems for details.

The hardware and software were designed concurrently. This means that the system is very efficient and not very prone to software errors. Because of the hardware addressing mechanisms and the memory protection bits, this machine was immune to many of the security issues that plague modern CPU architectures. It is near to impossible to break security, because it is enforced by a combination of hardware and software. No current x86/Power/Sparc/??? will ever be as secure as this kind of machine. (The Mill CPU has some of the same characteristics, but lacks tagged memory bits in main memory.)

As a field, computing took a wrong turn when it went after MIPS as a measure of "goodness". Using hardware resources to enforce secure computing address the fundamental problem of writing reliable software. It protects against coding errors and against malicious attacks. Now that hardware is cheap, the additional cost of tag bits in memory or address range checking could be easily supported.

But we're stuck with fast insecure architectures and there seems to be no turning back. It wouldn't be surprising that current systems are in fact less efficient when you take into account the cost of trying to make insecure hardware secure along with the costs associated with software failures and stolen data, corrupted data bases, down time, debugging, etc. (By the way, Burroughs systems had great up times, which was also true of Symbolics Lisp systems, which also had memory tag bits and was programmed from the bottom up in a high level language.)

Computerworld is a little slow

[rudy_wayne]

http://esj.com/articles/2010/1...

Oct 19, 2010

" This week the company updated its Libra and Dorado mainframe lines, touting a new all-Intel architecture,"

Re:what's the point anymore

[Vlad_the_Inhaler]

Speaking as someone who programs and administers computers on the Dorado line, that is total bollox. dreamchaser's post is also inaccurate.

Part of the Exec (= OS) is written in Assembler, the rest is in a proprietary language called Plus (a bit like Pascal) or C.
The same applies to processors and libraries provided by Unisys or third parties.
User programs can be in Fortran, Cobol, C or Assembler. Pascal and PL/1 were dropped a few years back, use of Plus in non-Unisys-written code is unsupported.

The key part of the article was Both the OSes will execute tasks on Intel's Xeon server chips through a firmware layer that translates the OS code for execution on x86 chips. Existing programs will work without recompilation, it is the Exec which needs to make the accomodations.

I don't know much (ok, anything at all) about the Libre lines but the Dorado machines have some very unusual characteristics such as 9-bit bytes which would render anything other than hardware compatibility a total disaster necessitating a forced conversion to another platform immediately.