This article is from the CD-Recordable FAQ, by Andy McFadden (email@example.com) with numerous contributions by others.
In computer terms, hardware is the stuff you can hit with a baseball bat,
and software is the stuff you can only swear at. Firmware is software that
lives on your hardware. In more concrete terms, the firmware on your CD
recorder is what controls the operation of the device, and handles
everything from decoding CD-ROM sectors to writing the disc table of
Sometimes there are bugs or missing features that are added by updates.
Firmware upgrades have been used to add features like disc-at-once
recording and fix bugs like reversed left and right audio channels.
Sometimes the upgrade will inadvertently add bugs, causing the recorder to
Firmware can be stored in an umodifiable form, such as a ROM chip, or in a
rewritable form, such as "flash" ROM. In the former case, firmware
upgrades are accomplished by physically removing a chip from inside the
device, and replacing it with a new one. Devices with "flashable"
firmware, on the other hand, can be upgraded by downloading a new set of
firmware over the Internet.
You have to be careful when upgrading the firmware on a drive yourself. If
it requires physical replacement, you run the risk of breaking pins off of
the chip. Flash upgrades won't result in physical damage, but in some
cases a failed upgrade can render the device unusable. Always follow the
instructions exactly, and NEVER do an upgrade with anything that didn't
come from the manufacturer or a trusted source.
Suppose you want to upgrade your recorder. The first step is to remember
famous words of wisdom: if it ain't broke, don't fix it!
The second step is to figure out if your firmware is upgradeable. The
manual should tell you. Most drives are, but some exceptions are noted for
specific drives in the subsections under (5-1).
The third step is to determine what version of firmware you currently
have. Some SCSI cards on PC or UNIX systems will display a list of
attached devices when the system boots. There's usually a column with a
version number in it.
On a PC running Win95, go into the Device Manager (either from the Control
Panels or by asking for Properties on My Computer), and find the CD-ROM
drives in the device tree. Select the CD-R drive, hit the "Properties"
button, and then click on the "Settings" Tab of the window that opens.
Look for "Firmware Revision".
Mac users with Toast can hit Command-R to display the information. If your
software doesn't have such a feature, you will need to run SCSI Tools to
check the identification string.
The fourth step is to find the upgrade file. Usually the manufacturer's
web site will have them. If not, sometimes you can find a repository on
the web. (There was a nice one on http://www.ahead.de/en/firmware.htm,
but that appears to be gone now.)
The fifth step is to apply the upgrade. This can be trivial or fairly
challenging, depending on the device. Be sure to read the instructions
*carefully* before applying the upgrade -- if it fails, the recorder could
be rendered inoperable.
Section (5-24) discusses the somewhat dangerous practice of flashing a
drive with firmware intended for a different drive.