Affordable 16GB SD Cards Now Available
While it was once a capacity unimaginably large for flash-based media, 16GB in a removable SDHC card for less than $100 is now a definite reality. A recent turn through several reputable online merchants revealed A-DATA 16GB SDHC Class 6 cards for $75 w/ free shipping at Newegg and $69.99 at Meritline. A-DATA has something of a spotty track record for reliability, including a 2GB card that failed me two years ago after just a few weeks' use. Nervous owners can still pick up a reliable Transcend 16GB card for $90 shipped with a free USB card reader drive.
While Palm has begun its transition to miniSD and microSD formats, there are still several two current Palm OS devices compatible with fullsize SDHC cards, the Treo 680 and 700 series. To date, Palm has not yet officially endorsed the use of any memory card in any format larger than 4GB in any of their Palm OS or Windows Mobile devices.
The Treo 680 has unofficially supported 4GB SDHC cards since launch. Additionally, Palm advises that the 1.10 ROM versions of the 700p officially support 4GB SDHC cards. I can verify that higher-capacity 8GB and 16GB cards do work in some fashion under the Garnet OS, but due to a 32-bit addressing bug, the Card Info app has severe issues when trying to see the available space on these cards. In short, the Palm OS "sees" things in 4GB (or less) chunks.
In addition to the limited successes noted above, a handful of adventurous users on various forum sites have reported success with hacking the Treo 650 to work with SDHC cards. WMExperts has a thread detailing how some users have hacked their Treo 700w/wx to be able to read from (but not write to) SDHC cards. The newer Treo 750 with the WM6 upgrade installed reportedly handles SDHC cards with aplomb.