Computer Technicians 202.5: Optical Drives and Firmware Flashing

Last time, on TNCT 202, you could read about the various functions of the system’s BIOS and the means to upgrade them for the sake of either improving stability, or adding various options. In this course we’ll examine the workings of optical drive firmware, the reasons to upgrade it and the general procedure how to do it, because like the BIOS, there are some advantages to having a flashed drive.

Simultaneous Translation

Much like the motherboard’s BIOS, any optical drive (which includes CD-RW, DVD-RW and their read-only counterparts) you encounter has to have a firmware chip – that is, something that handles the input-output data of the drive, controls the drive speed, manages the laser intensity and handles the regional code management system in case of DVD drives. The BIOS controls the input-output of the whole motherboard and some of its peripherals without going into details; on the other hand, the optical firmware handles its own working while going into details – every time you insert a CD or DVD, the firmware directs the lens to the tracks, spins the media up to speed depending on the location of the current track, and takes care of the data in both directions, ensuring whatever you read or write gets there properly.
Now, you’re probably thinking why you’d want to fix what isn’t broken. Common sense says exactly that. Engineers say quite the opposite, though: if it’s not broken, it doesn’t have enough features. Firmware upgrades are designed to give you a compromise, the best of both worlds – getting more features while keeping the drive from exploding. Or, at the very least, having it still reading and writing properly.

Mirror, mirror on the disc

So, what are all the benefits of a reflashed drive? To begin with, we’ll examine the differences between official and unofficial firmwares. Official firmware upgrades are usually sanctioned by the manufacturer themselves, and offer better reading and writing performance. To explain this, let’s delve into the data on a blank medium. Contrary to popular belief, no CD-R(W) or DVD-R(W) medium is truly blank even before writing onto it. The whole disc actually has a long spiral groove going along it, from the inside rim of the recordable area to the outside. This groove, called the ATIP (Absolute Time-In Pregroove) helps the drive read synchronously because it wobbles at a right angle to the groove – and since the drive’s reading along the groove, it can accurately clock itself and measure its rate of reading. The lead-in area (the one prior to the writable section) contains the ATIP as well – however, it holds several extra important bits of info. It includes data on the actual manufacturer of the medium, the type of dye used in the manufacturing process,m the maximum space on the actual disc and the maximum speed at which it was rated for recording.

How does that affect you as the end user? Simply put, each flash firmware contains a look-up table of manufacturers, dyes and speeds. Once the DVD reads the lead-in ATIP, it compares the block of data already in there to the look-up table. If they coincide, the DVD will get burned at, say 4x speed. A newer firmware (official or not) has the look-up table slightly upgraded, so to speak, so a medium previously burnable at 4x might now be rated for 8x burning – this is the result of testing a drive with media after its release. Along with that, a flashed recorder can also determine the laser intensity much better, which is good because nobody wants a caramelized DVD. Obviously, official firmware mostly helps recorders, not readers.