Do the White Intel iMac models have PCI slots or expansion bays?

No. All Intel-based iMacs are designed to be simple, compact, and relatively inexpensive, and consequently, there are no PCI slots or expansion bays. If expansion is a top priority, and cost is a factor, you would likely be better served with a used model from the Power Macintosh G4 or G5 series.

Do the White Intel iMac models support a "mirrored" external display? Dual displays?

Yes. Unlike earlier iMac models -- that either could not support an external display or could not officially support an external display -- the White Intel iMac systems support an external display in "extended desktop" or "screen spanning" mode, where the external display can be used as additional "work space".

What is the maximum supported resolution for an external display?

Apple reports that the White Intel iMac models are capable of supporting digital resolutions up to 1920x1200 and analog resolutions up to 2045x1536.

What are the capabilities of the optical drive provided by the White Intel iMac models? Which can read and write dual-layer DVDs?

All White Intel iMac models -- with the exception of the education-only iMac "Core Duo" 1.83 17-Inch (IG) and iMac "Core 2 Duo" 1.83 17-Inch, both discontinued -- can read and write dual-layer DVDs.

The discontinued education-only iMac "Core Duo" 1.83 17-Inch (IG) and iMac "Core 2 Duo" 1.83 17-Inch models are capable of writing to CD-RW and reading DVD, but cannot write to DVD (single or dual layer).

Do the White Intel iMac models have a ROM or BIOS?

The Intel-based iMac systems use Intel's Extensible Firmware Interface (EFI) rather than the traditional Macintosh ROM or PC BIOS.

Can you use the "remote holder" on the White iMac "Core Duo/Core 2 Duo" models to hold an iPod?

No. Although it might be tempting to use the magnetic "grip" mounted on the lower righthand side of the "White" Intel-based iMac models to hold an iPod, this is designed exclusively for use by the six-button Apple Remote. Page 43 of the User's Guide for the original iMac "Core Duo" warns that this portion of the system "contains a small magnet to rest your Apple Remote when it's not in use. To preserve the data on an external hard disk, memory card, iPod, or other magnetic media, avoid bringing them close to the magnet."

All "Aluminum" iMac models lack a magnet-equipped "remote holder."