In <9bRbQ.268488$sKi9.79563@fx14.iad> scott@alfter.diespammersdie.us (Scott Alfter) writes:

In article <md6n3pFgaflU8@mid.individual.net>,
Bob Eager <news0009@eager.cx> wrote:

Don't forget the ACT Sirius. A DOS machine, that crammed more data onto a >>diskette buy using a variable speed drive (5 speeds, I think).

Apple used the same trick with its 3.5" floppy drives to fit 800K onto a
disk that was only good for 720K elsewhere.

1975ish Superscope, whhich was in the midst of its breakup
with Sony, and was coming up with its own line of products,
sent our store promo materials for an upcoming phonograph
player which... varied the rotational velocity (and keeping
the same linear velocity).

This let the outer tracks of a record hold more material,
and thus extending the playing time.

(It never got past a couple of demo units, if even that)

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_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
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On Thu, 10 Jul 2025 15:50:44 +0000, danny burstein wrote:

1975ish Superscope, whhich was in the midst of its breakup with Sony,
and was coming up with its own line of products,
sent our store promo materials for an upcoming phonograph player
which...
varied the rotational velocity (and keeping the same linear velocity).

This let the outer tracks of a record hold more material,
and thus extending the playing time.

(It never got past a couple of demo units, if even that)

But later adopted for the CD, of course.

--
Using UNIX since v6 (1975)...

Use the BIG mirror service in the UK:
http://www.mirrorservice.org

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On Thu, 10 Jul 2025 15:50:44 -0000 (UTC), danny burstein wrote:

In <9bRbQ.268488$sKi9.79563@fx14.iad> scott@alfter.diespammersdie.us
(Scott Alfter) writes:

In article <md6n3pFgaflU8@mid.individual.net>,
Bob Eager <news0009@eager.cx> wrote:

Don't forget the ACT Sirius. A DOS machine, that crammed more data
onto a diskette buy using a variable speed drive (5 speeds, I
think).

Apple used the same trick with its 3.5" floppy drives to fit 800K
onto a disk that was only good for 720K elsewhere.

1975ish Superscope, whhich was in the midst of its breakup with
Sony, and was coming up with its own line of products, sent our
store promo materials for an upcoming phonograph player which...
varied the rotational velocity (and keeping the same linear
velocity).

AKA “CLV mode”, as popularized (if you can call it that) in
laserdiscs.

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Reply-To: jason@smbfc.net

On 10 Jul 2025 16:38:38 GMT, Bob Eager <news0009@eager.cx> wrote:

On Thu, 10 Jul 2025 15:50:44 +0000, danny burstein wrote:

1975ish Superscope, whhich was in the midst of its breakup with Sony,
and was coming up with its own line of products,
sent our store promo materials for an upcoming phonograph player
which...
varied the rotational velocity (and keeping the same linear velocity).

This let the outer tracks of a record hold more material,
and thus extending the playing time.

(It never got past a couple of demo units, if even that)

But later adopted for the CD, of course.

And one of the modes used by laserdiscs.

You had the CLV disks, (Constant Linear Velocity) which got you about 60 minutes per side at the cost of parlour trick of freeze-frame and what
not. (This is like a CD)

Then you had the CAV disks, (Constant Angular Velocity) disks which were good for about 30 minutes per side. (this is like a record). It's why I have to flip
my Star Wars Definitive Edition 4 times over the course of the movie...

--Jason

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In <105empl$2b6kf$2@dont-email.me> Jason Howe <jason@tatooine.smbfc.net> writes:

And one of the modes used by laserdiscs.

You had the CLV disks, (Constant Linear Velocity) which got you about 60 >minutes per side at the cost of parlour trick of freeze-frame and what
not. (This is like a CD)

Then you had the CAV disks, (Constant Angular Velocity) disks which were good >for about 30 minutes per side. (this is like a record). It's why I have to flip
my Star Wars Definitive Edition 4 times over the course of the movie...

If I'm remembering my collection of units correctly,
some of the more featured (and expensive!) LaserDisc players
had internal memory storage so yes, you could freeze frame
both types of disk.


--
_____________________________________________________
Knowledge may be power, but communications is the key
dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]

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* Origin: PANIX Public Access Internet and UNIX, NYC (3:633/280.2@fidonet)

Reply-To: jason@smbfc.net

On Fri, 18 Jul 2025 23:59:39 -0000 (UTC), danny burstein <dannyb@panix.com> wrote:

If I'm remembering my collection of units correctly,
some of the more featured (and expensive!) LaserDisc players
had internal memory storage so yes, you could freeze frame
both types of disk.

That sounds right.

What I always wanted was for the dual sided players to do a read-ahead buffer or
something for seemless side changes. That's a lot though considering the 30+ seconds it can take a player to "flip".

Thinking about it, I guess the better option would be two independent laser assemblies, so the side B laser could pick up when side A was over. Then you could do away with the roller coaster rails for the laser to move around the disk.

--
Jason

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