The System/370
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Although the System/360 was very successful, and in some ways, revolutionary and innovative, it also eschewed leading-edge technologies that left opportunities for other companies to exploit. To its credit, however, it was still selling well even six years after its announcement, and it laid a foundation for generations that followed it, of which the System/370 was first.
The initial launch of the System/370 in 1970 consisted of just two machines, the charismatically named 155 (running at almost 8.70 MHz) and 165 (running at 12.5 MHz). Naturally, both machines were compatible with programs written for the System/360 and could even use the same peripherals. Additionally, the performance was greatly improved, with the System/370 165 offering close to five times the performance of the System/360 65, the fastest machine available from that line when it was released in November 1965.
There were also several new technologies for the System/370, compared to the System/360. IBM finally moved to the integrated circuit, a change many people thought long overdue. Most models in the line had transistor memory rather than core memory. The System/370 also finally supported dynamic address translation (on all but the initial two models), which was an important technology for time sharing and virtual memory. There was also a very high-speed memory cache (80 ns for the 165), which IBM called a buffer. This was used by the processor to mitigate the relatively slow (two microsecond or 2,000 ns) main memory access time. Another important consideration was that the System/370 was built from the beginning with dual processors and multiprogramming in mind.
So, while the System/370 was not a spectacular announcement, it did plug up some glaring holes in the System/360, improved speed considerably, expanded the instruction set, and maintained a high degree of compatibility. It was a solid step forward and maintained IBM's dominance in the mainframe world.
But will it Blend?
Wonderful article, thanks Tom's. =]
Killed a good hour of my day, and I very much enjoyed it.
Really cool. One observation, on page 7 I think the magnetic drum is rotating 12,500 revolutions per minute, not per second....If my harddrive could spin at 12,500 revolutions per second I'm sure it could do all sorts of amazing things like flying or running Crysis.
Good article, however although not quite "Complete". There is no mention of Collosus (which was used to break Enigma codes from 1944) or The Manchester Small-Scale Experimental Machine (SSEM), nicknamed Baby, which was the world's first stored-program computer which ran its first program in June 1948.
So the ABC was in fact the first mobile computer? The picture does show wheels under the table at least
But I guess netbooks are easier to handle, and have batteries
I am with pugwash - its a good article but why does it seem like it is a bit US centric, no mention of Alan Turning or "Baby" and the Enigma code cracking machines of Bletchley Park
Err what about the Zuse Z3?
I agree with others, in that I am surprised that there was not even a mention of a Turing machine or other very early "computers".
Surely they qualified as Mainframes of their times?
It's a shame that multiplication, addition and division benchmarks are not persistently noted throughout the article.
I know that now a days it's very much dependent on software design, but it would still be nice to follow the progression in terms of calculation power of the machines.
25 pages??? i love ad block but damn this is annoying
Where can we get an 80/80 of this article without all of the noise? No PDF?
So.....can it play Crysis?
Out of curiosity, since its a metric I am more familiar with, what would the TeraFLOPS rating be in the newest and bestest from IBM. And how much would one of those bad boys set you back in the wallet.
Was a very educational and interesting article.
"The 704 was quite fast, being able to perform 4,000 integer multiplications or divides per second. However, as mentioned, it was also capable of doing floating point arithmetic natively and could perform almost 12,000 floating-point additions or subtractions per second. More than this, the 704 added index registers, which not only dramatically sped up branches, but also reduced program development time (since this was handled in hardware now)."
Many of these statements are sure to be wrong. 1) For sure, it would not be faster at floating point than integer. 2) Index registers have to do with memory addressing, not branching.
First, I agree with the title being misleading, and I apologize for it. It was never intended to be a complete guide, which would be virtually impossible. I don't know why that title was chosen.
The choice of computers was U.S. centric, because computers were U.S. centric. I chose only one mechanical computer, and it was made by IBM, since they were the dominant company. To add more computers would have been boring, and none of them were important technological milestones. So, while they might be specifically interesting to you, I was of the opinion too many computers from the same time frame would be boring. I almost chose the EDSAC over the EDVAC, but, went with the first design over the first implementation.
With regards to the index registers, "the IBM 704 added index registers and a “TSX” instruction that would branch to an address but leave the address of the TSX in an index register. A single unmodified branch could use that index register value to return."
Loops involve branching, branching involves memory addressing.
With regards to floating point vis-a-vis integer, you need to be more careful about what you're sure of. For one, multiplies and divides are generally slower, being much more complex. But, more to the point, this information is available directly from IBM.
As one who live the mainframe era from the 2k machines for $500K...this story is incomplete without the story of the competition that was the force behind the commercial introduction at a furious pace of things we take for granted today.
Any mention of mainframes without the Honeywell H-800 series, the H200 series or Multics leaves out systems that have had a large influence on computing as we know it. The H-800 was one of the first multiprocessing systems of the late '50s, the H-200 was Honeywell's answer to the 1401 in the '60s and Multics merely contributed much of the hardware architecture for the Intel CPU used in today's PCs and foreshadowed UNIX and many of the development tools we use today. I saw no mention of GE and their 600-6000 series. And NCR. (Remember the term "BUNCH" as the competitors to IBM.)
So starting in the '50s, you should also have the history of the BUNCH woven in even to their demise. Not every great idea originated from IMB (though many did).
What, and no mention of Lawrence Waterhouse and his work during WW2???
Nice article, it was fun to review that history. I would have added mention of the groundbreaking Cray machines, especially the seminal Cray-1 (and it's successor X-MP) as the first "supercomputer." The X-MP looked like a futuristic chaise lounge with the main circuits in a center column surrounded by a circular padded bench. They were so arranged to reduce interconnecting wire lengths, as the speed was limited by the time it took electrons to travel through the interconnects...a speed of light limitation! The later Cray-2 was unique in that it was completely immersed in a bath of liquid Flourinert to cool the dense circuitry.
the first computer programmers were all women!
http://abcnews.go.com/Technology/s [...] 187&page=1
Great Article! I learned something new today! I've never been so "into" the computer history before.
Thanks Rich Arzoomanian for writing this article.
all jokes aside, this is the best tom's hardware article i have read to date. thanks for taking the time, effort and expense for putting it together.