heheh. what about all those 13 inch tape reals? that and the cabinet sized reel-to-reel tape storage drives. I can remember a data center filled wall to wall with those (and the backend mainframe to manage them). Its amazing how much data we have stored on those old things that we can never retrieve (simply because no one is around that knows that programming environment and our current tech is too advanced to communicate with it).

DE n7zzt Eric

On Nov 4, 2015, at 12:15 PM, Matthew Chao wrote:

> Floppy disk, eh?  Need Viagra?--Matt, N1IBB.
> 
> At 01:54 PM 11/4/2015, you wrote:
>> Asking someone about a floppy disk is cause for sexual harassment these day=
>> s.
>> 
>> -----Original Message-----
>> From: For blind ham radio operators [mailto:[log in to unmask]] =
>> On Behalf Of Eric Oyen
>> Sent: Tuesday, November 3, 2015 10:37 PM
>> To: [log in to unmask]
>> Subject: Re: Useless Knowledge (was Laser Light)
>> 
>> thats almost as bad as knowing job control language for an IBM AS/360 =3D M=
>> ainframe. :) Also, working on reel to reel tape machines. Its really =3D to=
>> o bad that most people these days don't remember the technology that =3D wa=
>> s the predecessor to the current media. You ask a kid today what a =3D flop=
>> py disk is and they might look at you like a deer caught in the =3D headlig=
>> hts. Or how about coders these days that couldn't conceive of a =3D program=
>> written in basic and having to work tightly in only 8k of ram. =3D Pretty =
>> soon, I imagine, keyboards are going to be quaint reminders of an =3D old c=
>> omputing past.
>> 
>> DE n7zzt Eric
>> 
>> On Nov 3, 2015, at 8:11 PM, Tom Fowle wrote:
>> 
>>> Knowing how things work, or used to work is never useless.
>>> At the least it's interesting.
>>> =3D20
>>> Used to run 16 MM projectors in highschool in the 60s, but don't =3D
>> remember
>>> the filter. Maybe those school units didn't have the freeze frame.
>>> thanks for the fun
>>> tom Fowle WA6IVG
>>> =3D20
>>> On Tue, Nov 03, 2015 at 02:22:44PM -0600, Martin McCormick wrote:
>>>>     A lot of what is left of my brain is useless knowledge by  today's=20
>>>> standards. When I worked as a technician with the OSU  Audio Visual=20
>>>> Center in the eighties, I repaired 16-millimeter  film projectors=20
>>>> among many other things and I have a whole  treasure trove of trivia=20
>>>> in my head that doesn't get you very far  today.
>>>> =3D20
>>>>     Did you know, for instance, that if the film stops 
>> moving  for even=20
>>>> a fraction of a second that the heat from the projection  lamp is=20
>>>> sufficient to melt it? Most projectors had a freeze-frame  function=20
>>>> but it only worked because a special piece that greatly  reduced the=20
>>>> amount of heat/light was supposed to drop down  between the film gate=20
>>>> and the film, itself.
>>>> =3D20
>>>>     We had a few machines that came in because a mechanical  part that=20
>>>> held the filter piece up and out of the way failed and  the piece=20
>>>> would slowly swing down and cause the light output to  appear to go=20
>>>> very dim.
>>>> =3D20
>>>>     How does a person who is blind work on a film projector?
>>>> Most of the mechanical failures that befall 16-millimeter  projectors=20
>>>> cause audible issues also.
>>>> =3D20
>>>>     Sound film projectors must yank the film through the gate  in a=20
>>>> series of 24 very fast jerks per second so that each frame  of the=20
>>>> picture is still for 1/24 of a second. When the film  reaches the=20
>>>> sound pickup, it must not have any trace of the jerky  motion and=20
>>>> moves as smoothly as audio tape. There are failure  modes that cause=20
>>>> the film to move more smoothly than it should  through the film gate=20
>>>> and other failures that make it move in a  jerky manner through the=20
>>>> sound pickup. Those usually make the  machine clatter with an extra=20
>>>> loud sound or the sound has a  terrible flutter in the speed which is=20
>>>> unacceptable. It is  necessary to examine the film transport to=20
>>>> diagnose the problem  and fix the broken parts.
>>>> =3D20
>>>>     There is a Walt Disney movie which I think might be  "Bambee" in=20
>>>> which there is a scene where animals are talking to  each other while=20
>>>> under water. Their voices all sound fluttery  like someone with water=20
>>>> in their throat. One time, my wife and I  watched this film because=20
>>>> she wanted to see it again after many  years and I had never watched=20
>>>> it at all. I almost fell out of my  chair when that scene came on.=20
>>>> Some technician simply blocked the  rotation of the sound drum and fed=20
>>>> that audio in to the movie as  a special effect. I thought it was=20
>>>> brilliant and never imagined  that someone would actually want that=20
>>>> sound to appear, but it was  perfect for the scene.
>>>> =3D20
>>>>     I remember running across many weird problems that 
>> were  usually the=20
>>>> fault of wear and tear on belts, gears and clutches.
>>>> That's where I accumulated all this useless knowledge.
>>>> =3D20
>>>>     So, what makes the film stop and melt? Ripped out sprocket  holes=20
>>>> along the edge. That will turn torn-up film in to torn-up  melted=20
>>>> film. If this had been back in the really old days, the  film which=20
>>>> used to be made of celluloid would have burst in to  flame and started=20
>>>> a real fire.
>>>> =3D20
>>>> Martin
>>>> =3D20
>>>> Colin McDonald <[log in to unmask]> writes:
>>>>> ah, I love teachable moments!!!
>>>>> They call me a walking encyclopedia of mostly interesting, but =3D
>> useless
>>>>> facts...