The Psion Siena is a PDA (Personal Digital Assistant) made by Psion PLC and was released in 1996. Two versions of the Siena were released, one containing 512KB of memory and the second with 1MB.

The main power is provided by two AAA batteries and the backup power is provided by one cell style CR1620 battery. The batteries are held in a compartment below detachable casing in the top of the device. It does not have a socket for an external power source.

The Siena was of the same generation as the Psion 3 series but it has a smaller size screen (240x160 pixels) and an additional numeric pad situated next to the screen. The Siena uses the same 16bit NEC V30 processor as its predecessor the Series 3a. Although the Siena shares binary compatibility with the Series 3 many programs had to be modified due to the lower memory availability and smaller screen sizes.

Unlike the Series 3, the Siena does not have a bay for removable solid state disk drives; however, an external drive device is available which connects via an RS-232 serial port. The serial port also provided PC connectivity if used with the separately available PsiWin software and dial up access via the Travel modem accessory. Additional connectivity was available via the included infrared port which was located alongside the serial port.

Magazine Articles About Siena

• Personal Computer World - November 1996
• Acorn User - January 1997
• Byte December 1996