AVSIG: Time sink! wwswsigarch.jpg (7236 bytes)

✈ . . . . . . ✈ . . . . . ✈ . . . . ✈ . . . ✈ . . ✈ . ✈ . . ✈ . . . ✈ . . . . ✈ . . . . . ✈ . . . . . . Touch-and-Go to our Live Forum (This is a Read-only Archive of the 2004-2017 AVSIG Forum)


AVSIG Discussion Sections >> Hardware/Software

Pages: 1 | 2 | 3 | >> (show all)
Terry Carraway
Top Gun


Reged: 06/02/04
Posts: 7098
Loc: Maryland
Re: Time sink! [Re: Russell Holton]
      #419831 - 12/25/15 06:19 AM

Quote:

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




1GB?


Our first computer had a WHOPPING 105 MEGA byte hard drive. In the days were a 40MB drive was big, and most home computers had a 10MB drive.

First hard drive in a micro computer I ever used was 5MB.

And when I was with HP, the standard hard drive for technical minicomputers was 20 MB, 10MB fixed platter and a 10 MB removable. The removable was about the size of a large pizza box.

120 MB was a multi platter stack about 16-1" in diameter and loaded into a drive the size of a washing machine.

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


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ralph Jones
Top Gun


Reged: 08/31/01
Posts: 21214
Loc: 4CO2
Re: Time sink! [Re: Terry Carraway]
      #419839 - 12/25/15 09:37 AM

Quote:

Notice there are no more Crays.



Well, the supercomputer class isn't dead, but it's largely gone over to "embarrassingly parallel" architecture which is easier to cool...no more $500/gal Fluorinert <g>.

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


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mase Taylor
Top Gun


Reged: 04/29/04
Posts: 9446
Loc: SOCAL
Re: Time sink! [Re: Terry Carraway]
      #419844 - 12/25/15 11:01 AM

My fist computer had 16k memory and no hard drive. The OS loaded from a 5.25" floppy. My first hard drive was 10mb. I remember how thrilled I was to upgrade to an 80mb drive.

--------------------
Fly The Airplane As Far Into The Crash As Possible. - Bob Hoover 1922-2016 R.I.P.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ward Miller POU-NY
Top Gun


Reged: 05/05/04
Posts: 10508
Loc: New York
Time sink! [Re: Mase Taylor]
      #419846 - 12/25/15 11:59 AM

Mase, I bought my first IBM PC in 1981 for $3,000 -- two floppy drives and
16K, display and dot-matrix printer. That's about $7,500 or so in today's
dollars. Today, you can get exponentially more computer for one-tenth that
cost. Quite an improvement in just 35 years.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Russell Holton
AVSIG Member


Reged: 07/07/05
Posts: 14136
Re: Time sink! [Re: Terry Carraway]
      #419848 - 12/25/15 03:40 PM

Quote:

Notice there are no more Crays.




Too big.

IIRC, the Cray's unique shape was to reduce the distance from the ends so the signal could get from one end to the other quicker.

But modern PCs have a clock speed of around 3GHz. At 3GHz, light (or a clock signal) only travels about 4 inches. Lots of luck clocking anything the size of a Cray that fast. In fact, I think only the CPU in a PC runs that fast. The RAM and other buses run at a slower speed.

Notice that improvements in computing speed seem to come from multi-core. (Dual-core, Quad-core, Octa-core) We seem to have hit a wall on clock speeds. (Although the speed of the various buses have a big effect as well.)

(The clock speed of the original PC was 4.77 MHz. - light travels 200+ feet in a clock pulse.)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ralph Jones
Top Gun


Reged: 08/31/01
Posts: 21214
Loc: 4CO2
Re: Time sink! [Re: Russell Holton]
      #419854 - 12/25/15 04:11 PM

Quote:

(The clock speed of the original PC was 4.77 MHz. - light travels 200+ feet in a clock pulse.)



Back when "Amazing" Grace Hopper was consulting for DEC, she was famous for opening lectures by handing out 30-cm pieces of wire, which she described as nanoseconds...

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


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ray Tackett
Top Gun


Reged: 04/30/04
Posts: 8892
Loc: Philadelphia, USA
Time sink! [Re: Ralph Jones]
      #419855 - 12/25/15 05:03 PM

Re 30cm nanoseconds,

Back in that day (1969-70), I worked on Burroughs' Iliac IV. It had four
quadrants of 64 procesors each. Each quadrant was fed work and sent output
to a Burroughs B5500, the second biggest system Burroughs made at the time.
The four B5500s were controlled by a B7700, the biggest there was.

The Iliac processors consisted of circuit cards plugged in to 2X2 foot
backplanes. The pulses were so short that the backplane wiring was done with
very thin 52 ohm coaxial cables. The cable lengths on the backplane had to
be tweaked to get the timing right. For example, the two inputs to a simple
AND gate had to arrive simultaneously or the gate's output could never be
valid. The delay time in the coax also brought up the issue of exactly WHEN
the gate had a valid output, which affected the lengths of other cables.

Then, there was the fun troubleshooting standing waves and ringing when one
or more of the tiny 52 ohm termination resistors went bad or missing.

Lotsa fun tech to that one, all of which became obsolete decades ago.

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

Owner, Lake Wood Be Gone

Turning quality lumber into sawdust and noise since 2013.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mase Taylor
Top Gun


Reged: 04/29/04
Posts: 9446
Loc: SOCAL
Re: Time sink! [Re: Ray Tackett]
      #419856 - 12/25/15 05:49 PM Attachment (86 downloads)

Quote:


The four B5500s were controlled by a B7700, the biggest there was.









--------------------
Fly The Airplane As Far Into The Crash As Possible. - Bob Hoover 1922-2016 R.I.P.

Edited by Mase Taylor (12/25/15 05:50 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
sreyoB yrraL
AVSIG Member


Reged: 05/16/04
Posts: 9442
Re: Time sink! [Re: Russell Holton]
      #419859 - 12/25/15 08:45 PM

Quote:

(The clock speed of the original PC was 4.77 MHz. - light travels 200+ feet in a clock pulse.)



IIRC, the clock speed on the Z80 CPU in the TRS-80 Model I, my first computer, was 1.78 MHz.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Ward Miller POU-NY
Top Gun


Reged: 05/05/04
Posts: 10508
Loc: New York
Time sink! [Re: Mase Taylor]
      #419860 - 12/25/15 09:42 PM

Mase, seeing that lady at the tape drive reminds me of an unusual incident
that happened in the early 1960s. I was in a computer room that had about a
dozen 729 tape drives lined up -- this was before disks and was the way we
stored large amounts of data.

All of a sudden, they all stopped and began to unload the tapes from the
vacuum controlled chambers. One of the guys in the room shouted, "Did you
see that?" He then explained a car had just pulled out of the parking lot
in front of the computer room and the reflection of the sun off its
windshield had swept across the line of tape drives.

Back then the tapes had a small piece of aluminum foil near the end of the
tape. It would pass in front of an electric eye and the reflected beam would
signal the drive it was at the end of the tape and shut it down. The
reflected sunlight had swept across all the drives and their electric eyes
"sensed" it was the end of each tape, so each was unloaded.

They had been trying for weeks to find why the tapes would occasionally and
mysteriously unload. Of course they were always looking at the electrical
circuits for the cause.

The next time I was in that computer room, they had curtains on the windows
overlooking the parking lot.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | >> (show all)



Extra information
0 registered and 7 anonymous users are browsing this forum.

Moderator:  Mike Overly 

Print Topic

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled

Rating:
Topic views: 5038

Rate this topic

Jump to

Contact Us AVSIG

Powered by UBB.threads™ 6.5.5

Logout   Main Index    AVSIG Aviation Forum