The Treo 90 is a Palm OS PDA developed by Handspring.

The Treo 90 features a 12-bit standard (160x160) resolution color super-twisted nematic display, LED backlighting, a miniature QWERTY keyboard that replaces the usual Graffiti on other PDAs, an infrared port and an SD card slot.

[1] The original Palm OS (4.1H) lacks SDIO[broken anchor] support and reportedly has trouble formatting 128 megabyte SanDisk cards.

The ROM 4.1H3 update allows the use of SD Cards up to 1GB (confirmed)[citation needed].

Additionally the new SDIO capability allows users to expand the device's features with two expansion cards: the Palm Bluetooth card, which allows the Treo 90 to access the Internet, email and messages wirelessly with a Bluetooth-enabled mobile phone and MARGI Systems Presenter-and-Go which connects the Treo 90 directly to digital LCD projectors or other VGA devices to show business presentations stored on the Treo in full color.