Tech myths

[radhak]

LOML wanted to house her Canon 1100 in an old cell-phone jacket which has magnets in it's flaps to keep them closed. I thought the magnets might damage the SD card, but googled for confirmation.

Happily, this article busts that and other myths. Nice to know.

[germdoc]

That was so interesting I wanted to post it on this site. Then I remembered where I found the link...

[Bigbit]

Interesting read - thanks for the link.

[Copper]

Thanks! That was interesting. The article doesn't mention that Microdrives are still susceptible to magnets (Microdrives fit into CF card slots) since they are based on a magnet-based hard drive, AFAIK.

[catta12]

Thanks for the tech bust!

[LCHIEN]

magnetic susceptability of various storage media:

Floppy - yes
hard Disk Drive-yes
microdrive- yes
VHS tapes-yes
8mm cassettes-yes
Compact audio cassette-yes
CD-no
DVD-no
CD-R/RW-no
DVD-R/RW-no
USB Thumb-Flash Drive-no
SD, CF, XD, memory Stick (and micro-variants)-no
cards used in most cell phone and or cameras-no
iPod- depends on the type, Ipod Nano- no; 20-30 and 60G and video IPods, Yes

[radhak]

magnetic susceptability of various storage media:

Floppy - yes
hard Disk Drive-yes
microdrive- yes
VHS tapes-yes
8mm cassettes-yes
Compact audio cassette-yes
CD-no
DVD-no
CD-R/RW-no
DVD-R/RW-no
USB Thumb-Flash Drive-no
SD, CF, XD, memory Stick (and micro-variants)-no
cards used in most cell phone and or cameras-no
iPod- depends on the type, Ipod Nano- no; 20-30 and 60G and video IPods, Yes

According to the article, even Hard Disk Drives are not susceptible to magnets, at least not easily. Would need a real large one, not found with regular folks.

[cbrown]

magnetic susceptability of various storage media:

Floppy - yes
hard Disk Drive-yes
microdrive- yes
VHS tapes-yes
8mm cassettes-yes
Compact audio cassette-yes
CD-no
DVD-no
CD-R/RW-no
DVD-R/RW-no
USB Thumb-Flash Drive-no
SD, CF, XD, memory Stick (and micro-variants)-no
cards used in most cell phone and or cameras-no
iPod- depends on the type, Ipod Nano- no; 20-30 and 60G and video IPods, Yes

Magnetic core memory - yes. Also, be careful not to jar or shake it.

[BobSch]

Magnetic core memory - yes. Also, be careful not to jar or shake it.

And when was the last time you ran across any of those?

As far as hard drives are concerned — Yes, they are a magnetic media, but the housing acts as a shield so it would take a huge magnet to affect them.

[JSUPreston]

And when was the last time you ran across any of those?

I work for the government...any more questions?

I'm here all week, try the veal!

[jonmulzer]

Magnetic core memory - yes. Also, be careful not to jar or shake it.

I could certainly be wrong, since I have never even seen Magnetic core memory, but it is my understanding that core memory was chosen for early military computers because of their resistance to magnetic fields and EMP. They also used the read-only core rope memory for the Apollo missions for this reason. But hey, I have never even seen it, so I have for sure not used a computer that uses it and I certainly don't understand all the intricacies of it.

[crokett]

Wikipedia says that core memory is unaffected by EMP, I guess that means it is not affected by a magnet.

[LCHIEN]

EMP is electromagnetic pulse, an intense elecrtical field caused by nuclear explosions. The mot significant part is the electrical field which will damage most solid state electronics. While Core memory may survive (and survival is 2 parts - contents and operability), the electronics sense amps that read the memory will not survive (unless they use vacuum tubes).

[cbrown]

I haven't seen working magnetic core memory--only boards kept as artifacts in the recesses of the computer room--but it does look as if the folklore I heard about its vulnerability to physical shock and magnetism was inaccurate.

Extra credit to anyone who can put together a USB interface to make a 1K magnetic core flash drive.

Chris

[LCHIEN]

the funny thing about core memory is when you read it you destroy it. That is, that the memory content is destroyed. However, being only 1 and 0 basically that meant it got flipped. So after your read it, you had to read it again or write it to set it back the way it was.