Hard Drive Evolution, 1979-2011

I saw an old early model hard drive in a savage yard years ago. I think it was around 1.5 meg or maybe 15 meg capacity or something that and used around ten 12 inch record size disks and a 3/4 hp ac motor and belt drive to spin it! I think it probably weighed around 100 pounds too!

Now I wish I would have spent the $50 for it and bought it for its scrap aluminum and copper value they wanted for it being I have never seen one like it since.

I've used them, ours were mounted on something akin to a hospital trolley. 1.5Mb.

That big boy is certainly a piece of work, looks more like an engine.
Del

Nice pictures, but hardly a full story!! Sorry.

Check here:-

http://en.wikipedia.org/wiki/UNIVAC_FASTRAND

When a bearing went, you were in REAL trouble, look at the weight!!!

I worked for Sperry Univac for about 7 years.........73 to 80.

They had at least one of these on every nuclear sub and many surface UN Navy vessels that were built for many years. Stores computer.

There was a real "disk" version brought out about 1975 (memory only!!), which had vertically mounted disks (aluminium with oxide coating) x 5, each over 4 foot diameter......NOW YOU ARE TALKING STORAGE!!!

As an aside, Univac built the Apollo on-board computer for the moon shots, I worked on the commercial version many times in London and the surroundings......

Those were the days!!!!!

Well, the begining of the story seems to be here:

http://en.wikipedia.org/wiki/IBM_305_RAMAC

The year was 1956 !!!

See how it looked (the hard-disk drive only, not the computer):

It had 50 disks (24" diameter) to obtain 5 MB of storage (!!!), had an average access time of 600 ms and was used on a vacuum tube computer!!!!!!

Worked on a Sperry mini computer around 1978 or so.It had a 512 head drum drive that stored 10 MB of 16 bit data.Had an 8 inch floppy and a card reader for backup.16 Kb of Core memory.Used Octal System, highest input value was 17777.

Very dependable.It would save all vital info and shut down if it detected more than 2 cycles of input power out of spec.With full time generator running it at all times, this rarely happened.Utility power was used as backup.This computer ran an entire manufacturing plant, using Fortran, Cobal, and a proprietary communication program.

Even had a screen capture printer made by Sony, that would copy the CRT image to a printer.

Code had to be very tight and compact with no room for fluff.

If they still adhered to the same lean, tight code standards today, a lot less resources would be required to achieve the same results.Of course, now they do not need to be as efficient, with gigabytes of memory and terabyte hard drives.It amazes me how they accomplish so much with such Swiss Cheese programming.No wonder hackers are having a field day.

Anyone can drive a semi if you give them 40 acres to turn it around.(PPMS)

No offense intended to the real drivers out there, or anyone else for that matter.Just an old fogey reminiscing.

(IMHO)

Most of the computers I worked on for Univac had that special "shut down" system that simply recovered itself when the power returned. IBM engineers that I met much later simply did not believe it to be possible.....

The other bit that Univac had in its later CPUs was a "guessing" system that guessed at the possible result of a computation. If it was right, it saved time, if it was wrong the CPU crunched it at normal speed......the end result was a 30 to 50% speed improvement of the same CPU with it disabled.....many did not believe this either!!!

If Univac had standardised on an OS that was usable on all of its CPUs, they would have done much better, but as all upgrades had to be completely re-programmed, it was the same as when the customer went to a a different company, many eventually did......

They use a similar approach on some A/D converters, called "Successive Approximation"; basically a successive divide by 2 method to arrive at the correct answer.Sounds primitive, but it works well.

I was in college when the movie "2001" came out. Their moon shuttle had all these monitors with line graphics like you wouldn't believe!! My Gawd that was amazing!! I watch the same movie today, and those graphics are so blah.

I would love to go back in time to say 1970 with a modern laptop to show the college profs (and students) what they could expect.

"Yeah! I can get you one of these but the lead time is a bit long... say 40 years." We have come a long ways...

Bill