Since disc rot is often caused by the corrosion of aluminum, this means that DVDs are more resistant to disc rot. This means that a scratch on either surface of a DVD is not as likely to reach the reflective layer and expose it to environmental contamination and perhaps to cause corrosion, perhaps progressive corrosion. The thin 0.25-0.5mm layer of protective lacquer is equivalent.ĭVDs have a different structure from CDs, using a plastic disc over the reflecting layer. In the case of CD-R and CD-RW media, the materials used in the reflecting layer are more complex than a simple aluminium layer, but also can present problems if contaminated. CD reflective layers are so thin that this passivation is less effective. In ordinary use, a surface layer of aluminium oxide is formed quickly when an aluminium surface is exposed to the atmosphere it serves as passivation for the bulk aluminium with regard to many, but not all, contaminants. The reflective layer is typically aluminium, which reacts easily with several commonly encountered chemicals such as oxygen, sulfur, and certain ions carried by liquid water. It is rarely uniformly thick thickness variations are usually visible. The lacquer protecting the edge of an optical disc can usually be seen without magnification.
While it seems to work fine in many cases, some users ended up with their Mac not booting any more afterwards.In CDs, the reflective layer is immediately beneath a thin protective layer of lacquer, and is also exposed at the edge of the disc. There is also a simpler method which consists of just typing in a terminal:
Jump through to the post to read the full answer, but here is the ‘quick fix’ that might work for you. In fact Luz provides two options, one it seems is more reliable than the other. It’s a little more complicated than the steps outlined above, so if you’ve only got one internet enabled device you might want to print out/copy down the instructions before you get started!
If you’re running Mac OS X El Capitan (10.11) or later you’ll need to check out this updated post from Luz, on how to successfully tackle the same issue.
The driver recognizes a boot parameter named “mbasd” (Mac Book Air Super Drive), which sets a flag in the driver which both overrides the check for the MBA and also tweaks something related to USB power management (the Superdrive probably needs more power than regular USB allows). What is the file we just edited? Thanks to the Luz from the blog you can once again be illuminated…Īpparently, Apple engineers had the need to test the Superdrive with non-MacBook Air computers themselves, so the driver already has an option built-in to work on officially unsupported machines! All you need to do is enable that option, as follows: Restart and plug in your Superdrive and you should be good to go. On line 8, or between the type in ‘mbasd=1’ so it looks like this… I use Text Wrangler which is both excellent and free. Open the file with Text Edit or any other text editor. You can get to the hidden Library folder by holding down ALT when clicking on the ‘Go’ menu in a Finder window. Mac HD/Library/Preferences/SystemConfiguration/ Navigate to this file (click image for larger view) and back it up by making a copy of it to your Desktop in case anything goes wrong. How To Make a Mac Laptop Recognise an External DVD Drive If you follow these steps you’re obviously doing this all at your own risk. External DVD drive functional happiness is all thanks to this blog for the fix. I’ve not tested this on OS X Yosemite, but I know it works on Mountain Lion and it should work on Mavericks and in most other OS X versions I believe.
This week I had to get around this exact scenario, as it appears the internal drive is failing on my 17″ Macbook Pro (sigh), but the solution is actually very simple. If you’ve ever tried to plug in an Apple Superdrive (external DVD drive) into a Macbook Pro or other Mac laptop with an internal DVD drive, you may have struggled to get the laptop to recognise the external drive and therefore be able to use it at all. How To Use A Superdrive on a Mac Laptop With An Internal DVD Drive