Two questions

K

KellyClarksonTV

Jan 1, 1970
0
First, why is the record button on a tape recorder always Red? Does it have any
significant meaning?

Also, why does the play button also get activated when you push record? I
actually looked inside to see what happenes when you push play and then when
you push record. The record process has an extra square-shaped object comming
down on the tape (persumably to record), but the play head is a few cm's down
from the recording head. Wouldn't this cause echos?

R

Rich Grise

Jan 1, 1970
0
First, why is the record button on a tape recorder always Red? Does it
have any significant meaning?
It's easier to see.
Also, why does the play button also get activated when you push record? I
actually looked inside to see what happenes when you push play and then
when you push record. The record process has an extra square-shaped object
comming down on the tape (persumably to record), but the play head is a
few cm's down from the recording head. Wouldn't this cause echos?

head. It uses all the same stuff, except in record, the erase head is
erasing, and the input and output of the amplifier are swapped.

M

Mark

Jan 1, 1970
0
First, why is the record button on a tape recorder always Red? Does it have any
significant meaning?

To warn the user that they're about to erase anything
existing on the tape.--
Mark

The truth as I perceive it to be.

Triple Z is spam control.

K

KellyClarksonTV

Jan 1, 1970
0
actually, I also wanted to know, is it possible to recover something you
recorded over?

R

Rich Grise

Jan 1, 1970
0
KellyClarksonTV said:
actually, I also wanted to know, is it possible to recover something you
recorded over?

I don't know - why don't you give it a try, and let us know?

K

KellyClarksonTV

Jan 1, 1970
0
I doubt it ... because if material could be recovered from an erased tape, you
could hold lots (possible infinite) of information on a tape, since everytime
you needed something, you would "unerase" it. If this technology existed,
businesses would profit a lot by designing data storage devices that used this
principle. But how about if the tape was erased just once and recently? Is it
possible?

J

Julie

Jan 1, 1970
0
KellyClarksonTV said:
actually, I also wanted to know, is it possible to recover something you
recorded over?

Yes.

K

KellyClarksonTV

Jan 1, 1970
0
Then how?

If not possible, it's scary, because all it takes is a soft push of the record
button on your remote control and your wedding on video could be gone forever.

When I was a 4th grader or so I used to compulsively worry about accidentally
pushing record. I'd have to double check every night before I go to bed, after
rewinding something, before leaving for school, etc ...

C

[email protected]

Jan 1, 1970
0
Then how?

If not possible, it's scary, because all it takes is a soft push of the record
button on your remote control and your wedding on video could be gone forever.

When I was a 4th grader or so I used to compulsively worry about accidentally
pushing record. I'd have to double check every night before I go to bed, after
rewinding something, before leaving for school, etc ...

You sure that wasn't your only compulsion, considering the other posts

It is possible to recover some data from linearly recorded tapes as
the recorded segment may not be aligned perfectly with the erase head
or the record head alignment might be a little different. You'd need
FBI/NSA level of expertise and equipment to pull this off though.

-Chris

J

Julie

Jan 1, 1970
0
KellyClarksonTV said:
Then how?

Chris answered pretty much what I what I know about it. The restoration is
highly lossy at best.
If not possible, it's scary, because all it takes is a soft push of the record
button on your remote control and your wedding on video could be gone forever.

That is the main reason that recordable media such as video tapes have a 'write
protect tab' to prevent just such occurrences. Now all you have to worry about
When I was a 4th grader or so I used to compulsively worry about accidentally
pushing record. I'd have to double check every night before I go to bed, after
rewinding something, before leaving for school, etc ...

?!

K

Karl Uppiano

Jan 1, 1970
0
KellyClarksonTV said:
actually, I also wanted to know, is it possible to recover something you
recorded over?

Not likely. The erase head saturates the tape with a strong ultrasonic AC
signal, meaning that the tape is alternately magnetized as far as possible
in one direction, then the other. All usable signals are recorded at less
than this level, so they are effectively obliterated. The same thing happens
if a tape is "bulk" erased. In that case, the tape is brought into a strong
alternating magnetic field that does the same thing as the erase head, only
to the entire tape pack.

K

KellyClarksonTV

Jan 1, 1970
0
but I've seen TV shows where the FBI recovered deleted files from computers.
Isn't that the same concept?

S

Sporkman

Jan 1, 1970
0
KellyClarksonTV said:
but I've seen TV shows where the FBI recovered deleted files from computers.
Isn't that the same concept?

NOT same concept. An "erased" file on a disk is actually not
necessarily written over. It's just that it's place-marker in the file
system doesn't know it's there or where to find it any more. The space
on the hard drive is then open for writing, whether or not anything has
actually been written to it. Therefore the data MAY be available for
recovery, although the chances for recovery are reduced over time by the
probability of new data being written. With magnetic tape the erase
head actually does overwrite (erase) what's there, allowing the record
head to almost immediately write new information to the same spot.

'Sporky'

J

JeffM

Jan 1, 1970
0
I've seen TV shows where the FBI recovered deleted files from computers.
An "erased" file on a disk is actually not necessarily written over.
It's just that it's place-marker in the file allocation table
Sporkman

Not deleted--altered. In the case of M$OSes, the 1st character is changed to a lowercase rho (ASCII 229). The OS is designed to ignore these names. so the system doesn't know it's there or where to find it any more. Yes. File recovery utilities, however, recognize the altered names. S Sporkman Jan 1, 1970 0 JeffM said: Not deleted--altered. In the case of M$ OSes,
the 1st character is changed to a lowercase rho (ASCII 229).
The OS is designed to ignore these names.

Yes. File recovery utilities, however, recognize the altered names.

Quite right and I defer to your better explanation.

R

Robert Stankowic

Jan 1, 1970
0
Sporkman said:
NOT same concept. An "erased" file on a disk is actually not
necessarily written over. It's just that it's place-marker in the
so the
system doesn't know it's there or where to find it any more. The
space on the hard drive is then open for writing, whether or not
anything has
actually been written to it. Therefore the data MAY be available
for recovery, although the chances for recovery are reduced over
time by the
probability of new data being written. With magnetic tape the erase
head actually does overwrite (erase) what's there, allowing the
record head to almost immediately write new information to the same
spot.

One major difference AFAIK is, that there is no erase head on
harddisks, and thus, even if existing info is overwritten just once,
some information (at the edges of the track) is still there and can
be recovered with special equipment.

R

Robert Baer

Jan 1, 1970
0
Mark said:
To warn the user that they're about to erase anything
existing on the tape.
--
Mark

The truth as I perceive it to be.

Triple Z is spam control.

"Triple Z is spam control." - Does that mean that if i go to sleep,
that i will get no spam?

C

Charles Jean

Jan 1, 1970
0
One major difference AFAIK is, that there is no erase head on
harddisks, and thus, even if existing info is overwritten just once,
some information (at the edges of the track) is still there and can
be recovered with special equipment.
---

has the ability to do a DOD "government wipe" of all free area on the
disk, including the un-overwritten file "feathers" you mention. Takes
a while, though.
If God hadn't intended us to eat animals,
He wouldn't have made them out of MEAT!
- John Cleese

M

Mark

Jan 1, 1970
0
"Triple Z is spam control." - Does that mean that if i go to sleep,
that i will get no spam?
Why don't you try it and tell us if it works?

--
Mark

The truth as I perceive it to be.

Triple Z is spam control.

R

Robert Baer

Jan 1, 1970
0
Mark said:
Why don't you try it and tell us if it works?

--
Mark

The truth as I perceive it to be.

Triple Z is spam control.

I tried the ZZZ's and the phone woke me up...

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