CD vs DVD

[Pete Simmons]

Can you tell by looking which is which?

I am correct saying you cannot read a DVD in a CD reader - right??


I had someone send me a file on a disk. I think they sent a DVD. I told them I need a CD.

[Joe Pelonio]

No, they look the same and you can't read a DVD in a CD drive. I put in a DVD R/W drive, was $59 and easy to install, because it holds so much more and use it mostly for backing up data files.

[Darren Null]

If you're a bit nervous about installation/need 1 drive for multiple machines, you can also get a DVD/RW in a caddy that plugs in via USB. Slower, but you don't have to buy 12 of them if you have a computer factory.

As an extremely general and innaccurate rule of thumb- if the playing surface is purplish, it's probably a DVD (the deep purple Ritek dye colour is a sign that it's probably a good DVD and your data will last as long as you write on it with a water-based pen*) and a greenish colour means that you're quite possibly looking at a CD. They normally have the capacity written on the disk too, which is a much more reliable way of telling- 650/700/800Mb is a CD 4.7Gb is a DVD.

* If you write on a DVD with a spirit-based pen, the spirit leaches through and mungs up your data within 18 months-3 years. Best to buy a water-based marking pen for marking your disks. If none of your old CDs/DVDs work, that's probably why.

[Mike Null]

Along that same line, I installed the hard drive from my old PC which I was scrapping into the newer one as an extra storage space. It didn't cost anything and only took a half hour.

[Darren Null]

I've gone over to mostly laptops now, and the hard disks are different. €25 buys you an external caddy that you can fit your old HDD in and use it as backup/extra storage...dunno what that is in the States...probably cheaper.

A note if you're buying the cheap HDD caddies- they often don't spin the hard drive down, so HDDs placed in them will have a relatively short life if you leave them plugged in all the time. So either only plug them in/switch them on when you're using them or buy a more expensive one that does spin the HDD down after an interval of non-use.

EDIT: You can also get the caddys for the laptop HDDs, and they are a worthwhile investment too- both for recovering data from dead laptops, and it's quite good to have 80Gb of storage that fits in a pocket. The nice ones take data and power from 1 USB lead- the less satisfactory ones use 2 leads- on for power, one for data, thus using 2 USB sockets.

[John Noell]

Usually it is the computer (in the power options) that controls when to stop the drive, not the external case. Most drives are rated for VERY long spin life so we do not see that as a big issue. To make matters more complicated, the newer SATA drives are a bit different what we've had for the last 15+ years. Case/caddy type must match drive (older = PATA, newer = SATA). Some drives (it's not the case/caddy) require more than 500 milliamps which is the limit of a single USB port. (So if it needs more power you need two connections to the computer, one for power+data and one more for extra power.) [New to lasers - longtime computer tech.]