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Russell Holton
AVSIG Member


Reged: 07/07/05
Posts: 14136
Time sink!
      #419718 - 12/23/15 07:13 PM

Ran across this blog that details some repairs made to a IBM 1401 - a 50 years old main frame computer.

Qui-binary arithmetic, anyone?


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Ward Miller POU-NY
Top Gun


Reged: 05/05/04
Posts: 10508
Loc: New York
Time sink! [Re: Russell Holton]
      #419731 - 12/23/15 10:10 PM

Russell, the IBM 1401 was first produced in 1959. When production ceased in
1971, 12,000 had been produced. The original forecast was for about 100.

During the early 1960s I managed the development of a bunch of its system
programs -- Autocoder, RPG, IOCS, FORTRAN, COBOL and Sort. It was a
wonderful machine. We used to debug our programs running a 1401 emulator on
the IBM 701 and 704 because there were a lot more of them available at the
time than 1401s.


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Ray Tackett
Top Gun


Reged: 04/30/04
Posts: 8892
Loc: Philadelphia, USA
Time sink! [Re: Russell Holton]
      #419732 - 12/23/15 10:18 PM

Whee! I was teaching parts of that stuff, mainly error detection and
correction using Hamming code, to graduate students in the late 1980s. IMO
it's still a neat example of fun things you can do with mathematics.

The Wikipedia article:

https://en.wikipedia.org/wiki/Hamming_code

is way too narrow in scope. It discusses only telecommunications, where I
have never seen a Hamming code used. I saw it in very large (for the day)
memory arrays which used hundreds of not-so-reliable 1, 2, or 4Kbit DRAM
chips.

--------------------
Ray,

Owner, Lake Wood Be Gone

Turning quality lumber into sawdust and noise since 2013.


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Terry Carraway
Top Gun


Reged: 06/02/04
Posts: 7098
Loc: Maryland
Re: Time sink! [Re: Ray Tackett]
      #419745 - 12/24/15 05:48 AM

Quote:

The Wikipedia article:

https://en.wikipedia.org/wiki/Hamming_code

is way too narrow in scope. It discusses only telecommunications, where I have never seen a Hamming code used. I saw it in very large (for the day) memory arrays which used hundreds of not-so-reliable 1, 2, or 4Kbit DRAM chips.




Then edit the article and add your knowledge. :)

--------------------
Terry
Mostly 0W3


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Terry Carraway
Top Gun


Reged: 06/02/04
Posts: 7098
Loc: Maryland
Re: Time sink! [Re: Ward Miller POU-NY]
      #419746 - 12/24/15 05:50 AM

Quote:

Russell, the IBM 1401 was first produced in 1959. When production ceased in 1971, 12,000 had been produced. The original forecast was for about 100.




Didn't the head of IBM one time state that he figured the world market for computers was something like 8?

Oh, here is the wiki quote:

Quote:

Although Watson is well known for his alleged 1943 statement, "I think there is a world market for maybe five computers," there is scant evidence he made it.




--------------------
Terry
Mostly 0W3


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Russell Holton
AVSIG Member


Reged: 07/07/05
Posts: 14136
Re: Time sink! [Re: Terry Carraway]
      #419758 - 12/24/15 12:49 PM

Quote:

Quote:

Although Watson is well known for his alleged 1943 statement, "I think there is a world market for maybe five computers," there is scant evidence he made it.







Given the cost to buy and operate a 1940's computer, he might have well have been right.

As I recall, IBM was formed to help the government tabulate the US Census. One of the jobs of the early computers was to create the ballistics table for firing big guns. Then there was the one built for code-breaking. All-in-all, applications that only first world governments would have or be able to afford.

But once they got cheap and powerful enough to do business accounting, the market suddenly got much, much larger. And with shrinking size, costs and increasing power, we've entered an era that even the science-fiction writers got wrong. Notice the difference in computers between the original Star Trek series (essentially a tabulator) and the later ones (with a holodeck).

Here's an illustration of the power of today's computers:

Quote:

Could an IBM mainframe from the 1960s mine Bitcoin? The idea seemed crazy, so I decided to find out. I implemented the Bitcoin hash algorithm in assembly code for the IBM 1401 and tested it on a working vintage mainframe. It turns out that this computer could mine, but so slowly it would take more than the lifetime of the universe to successfully mine a block. While modern hardware can compute billions of hashes per second, the 1401 takes 80 seconds to compute a single hash. This illustrates the improvement of computer performance in the past decades, most famously described by Moore's Law.




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Ralph Jones
Top Gun


Reged: 08/31/01
Posts: 21214
Loc: 4CO2
Re: Time sink! [Re: Russell Holton]
      #419763 - 12/24/15 02:01 PM

I like to speculate on what Richard Feynman could have done in 1944 with an Apple II...

--------------------
Ralph Jones
LS-4a N49LS 6R


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Ward Miller POU-NY
Top Gun


Reged: 05/05/04
Posts: 10508
Loc: New York
Time sink! [Re: Russell Holton]
      #419783 - 12/24/15 05:36 PM

Russell, the IBM 1401 we're talking about here had 1.4K memory in the
engineering model. The first ones delivered to customers had 4K and had
punched card input and output. A year later they shipped 8K versions, then
12K. Eventually, the largest was 16K.

With all that, we learned to write pretty tight code. <g>


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Russell Holton
AVSIG Member


Reged: 07/07/05
Posts: 14136
Re: Time sink! [Re: Ward Miller POU-NY]
      #419786 - 12/24/15 06:10 PM

Yeah, I know. I remember when a 1GB drive was a big deal. Today, you can't even load a modern OS on one.

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Terry Carraway
Top Gun


Reged: 06/02/04
Posts: 7098
Loc: Maryland
Re: Time sink! [Re: Russell Holton]
      #419830 - 12/25/15 06:16 AM

The last is like I saw a LONG time ago, where a physicist wrote that a 386/25 was faster than a Cray.

The 386 took 24 hours to run his problem. The Cray took maybe 100 milliseconds.

BUT....

It took him 26 hours to get those 100 ms on the Cray, so the 386 was done 2 hours earlier than the Cray.

Notice there are no more Crays.

--------------------
Terry
Mostly 0W3


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