I didn't do programming, but yes, I do remember the large floppies.  That's what 
the first IBM word processors, I think they were called DisplayWriter or 
something, used.  There was a huge box that was the floppy drive that connected 
to the word processor.  What a Gawd-awful clunky sound it made when it was 
writing to the floppy.


----- Original Message ----- 
From: Tom Fowle
To: [log in to unmask]
Sent: Tuesday, November 03, 2015 11:49 PM
Subject: Re: Useless Knowledge (was Laser Light)


My first embedded systems projects were in 8085 assembly with a
2716(2Kbytes) of eprom and 256 bytes of ram.
You couldn't even find that small a setup today! <GRIN>
Anybody remember 8 inch floppies?

Tom Fowle WA6IVG

On Tue, Nov 03, 2015 at 08:37:16PM -0700, Eric Oyen wrote:
> thats almost as bad as knowing job control language for an IBM AS/360 =
> Mainframe. :) Also, working on reel to reel tape machines. Its really =
> too bad that most people these days don't remember the technology that =
> was the predecessor to the current media. You ask a kid today what a =
> floppy disk is and they might look at you like a deer caught in the =
> headlights. Or how about coders these days that couldn't conceive of a =
> program written in basic and having to work tightly in only 8k of ram. =
> Pretty soon, I imagine, keyboards are going to be quaint reminders of an =
> old computing 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.
> >=20
> > Used to run 16 MM projectors in highschool in the 60s, but don't =
> remember
> > the filter. Maybe those school units didn't have the freeze frame.
> > thanks for the fun
> > tom Fowle WA6IVG
> >=20
> > 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 standards. When I worked as a technician with the OSU
> >> Audio Visual Center in the eighties, I repaired 16-millimeter
> >> film projectors among many other things and I have a whole
> >> treasure trove of trivia in my head that doesn't get you very far
> >> today.
> >>=20
> >> Did you know, for instance, that if the film stops moving
> >> for even a fraction of a second that the heat from the projection
> >> lamp is sufficient to melt it? Most projectors had a freeze-frame
> >> function but it only worked because a special piece that greatly
> >> reduced the amount of heat/light was supposed to drop down
> >> between the film gate and the film, itself.
> >>=20
> >> We had a few machines that came in because a mechanical
> >> part that held the filter piece up and out of the way failed and
> >> the piece would slowly swing down and cause the light output to
> >> appear to go very dim.
> >>=20
> >> How does a person who is blind work on a film projector?
> >> Most of the mechanical failures that befall 16-millimeter
> >> projectors cause audible issues also.
> >>=20
> >> Sound film projectors must yank the film through the gate
> >> in a series of 24 very fast jerks per second so that each frame
> >> of the picture is still for 1/24 of a second. When the film
> >> reaches the sound pickup, it must not have any trace of the jerky
> >> motion and moves as smoothly as audio tape. There are failure
> >> modes that cause the film to move more smoothly than it should
> >> through the film gate and other failures that make it move in a
> >> jerky manner through the sound pickup. Those usually make the
> >> machine clatter with an extra loud sound or the sound has a
> >> terrible flutter in the speed which is unacceptable. It is
> >> necessary to examine the film transport to diagnose the problem
> >> and fix the broken parts.
> >>=20
> >> There is a Walt Disney movie which I think might be
> >> "Bambee" in which there is a scene where animals are talking to
> >> each other while under water. Their voices all sound fluttery
> >> like someone with water in their throat. One time, my wife and I
> >> watched this film because she wanted to see it again after many
> >> years and I had never watched it at all. I almost fell out of my
> >> chair when that scene came on. Some technician simply blocked the
> >> rotation of the sound drum and fed that audio in to the movie as
> >> a special effect. I thought it was brilliant and never imagined
> >> that someone would actually want that sound to appear, but it was
> >> perfect for the scene.
> >>=20
> >> I remember running across many weird problems that were
> >> usually the fault of wear and tear on belts, gears and clutches.
> >> That's where I accumulated all this useless knowledge.
> >>=20
> >> So, what makes the film stop and melt? Ripped out sprocket
> >> holes along the edge. That will turn torn-up film in to torn-up
> >> melted film. If this had been back in the really old days, the
> >> film which used to be made of celluloid would have burst in to
> >> flame and started a real fire.
> >>=20
> >> Martin
> >>=20
> >> Colin McDonald <[log in to unmask]> writes:
> >>> ah, I love teachable moments!!!
> >>> They call me a walking encyclopedia of mostly interesting, but =
> useless
> >>> facts...