Admittedly nobody has asked me any questions, so the term “FAQ” is a bit misleading.  However, the following questions are anticipated to be frequently asked:

Is the application safe?

dLight only uses published Apple API’s and performs absolutely no file I/O beyond Apple’s default application preferences.  It operates in user application space and has no access to devices beyond one-way statistics information supplied by the kernel.

What is the “Sample Interval?”

dLight analyzes disk activity periodically.  You may set this between 0.1 and 1.0 second.  More frequent intervals will result in slightly higher CPU utilization.  For reference on a 2GHz Intel Mac the 0.1 second interval results in 0.7% CPU utilization while the 1.0 second interval results in 0.1% CPU utilization.

What is the “Threshold Indicator?”

Disk activity (read or write) exceeding the threshold will cause the icon to turn red.  Users may use this to distinguish between casual disk access and significant activity.

Why don’t I get an icon for every disk?

Originally Apple provided no access to the menu bar for status items like dLight.  This was to prevent the inevitable clutter of items as developers added a status item for every application.  Think about the windows system tray...  They eventually acquiesced with some basic guidelines.  The decision to aggregate disk activity was one of aesthetics. 

Why doesn’t the program display a meter so we can see the exact disk activity?

Because it doesn’t.  Knowing there is currently a disk read at 3.5390 MB/s and a write at 4.9812 MB/s may be fascinating to some users, but this really isn’t useful information.  dLight makes a compromise to such  complaints by providing a “very busy” indicator.  At a glance you can answer the question “Are my disks idle, busy, or really busy?”

How do I set dLight to launch when I log in?

Like any application, this option is provided in System Preferences->Accounts->Login Items.  Just drag dLight.app into the list.

Where is the manual?

There isn’t one.

What’s with the 5.25” floppy icon?

Pure nostalgia.  Remember the satisfying “thump” when you locked the disk in place?  You just don’t get that with a USB thumb drive.

Where is the dock icon when the program is running?

dLight is a “faceless” application.  It has no dock icon, nor does it need one.

Does it work with versions of Mac OSX prior to 10.5?

Maybe.  Probably.  Give it a whirl and let me know.  Remember the software license absolves me from any liability.