The Revo is a Psion PDA which runs EPOC (now SymbianOS). It is based on the same "Windermere" technology as the Series 5MX.

Psion also released an upgraded version of the Revo called the Revo Plus. This is almost identical but has 16 megabytes of RAM over the normal 8. It also has a copy of Opera included. Diamond marketed a rebranded version in America called the Mako.

Features

  • 36 Mhz ARM 7110 processor
  • 8MB internal memory (Revo) or 16MB (Revo Plus/Mako)
  • 480x160 LCD display. Touchscreen and Stylus.
  • 115.2kbit serial connection to host computer via a docking cradle.
  • IrDA
  • Digital sound output through an 8khz internal speaker.

Differences between the Revo and the 5MX

  • Smaller screen (the 5MX has a 640x240 pixel screen)
  • No backlight. It is rumored that the backlight was deliberately removed so it would not compete with the 5MX.
  • Less RAM: The 5MX usually has 16 or 24 megabytes of memory, the Revo has only 8 meg.
  • No compactflash slot.
  • Slightly less keys on the keyboard. The keyboard is also of a different design: they are more spongy whereas the 5MX has proper solid keys with feedback.
  • A cradle, whereas the 5MX has a cable you connect to the back.
  • A different battery system. The 5MX had a battery compartment you could open to change the batteries, but in the Revo the batteries are sealed inside the case. This means the only way to change the batteries is to get them changed by an authorised dealer. However, the batteries are rechargable and designed to be repeatedly discharged and recharged in small amounts.

    It also apparently has a quite advanced system for monitoring the battery level from the battery current.

  • No microphone. The Revo can play back sound just like the 5MX but has no microphone to record with. Neither does it have the small dictaphone buttons the 5MX has mounted on the outside of the case.
  • Smaller case. The Revo is probably the smallest PDA with a keyboard you can get and when closed looks very sexy ;)
Apart from these differences it is pretty much architecturally identical. Some of the software is slightly different: the Revo is marketed somewhat as a connected organiser, and has tools for accessing the Internet via an Infrared modem (Psion sell an Infrared travel modem separately).

Hacking your Revo

The Revo is pretty sealed - there are no screws visible anywhere on the case. However, it is possible to get inside (danger: this may damage your machine and invalidate your warranty):

  1. If you prise off the metal plate with the Psion logo on the front of the case, there are two hidden rods which hold the screen to the silver back part. Lifting up their ends and sliding them along the groove they are in will detach the screen and allow you to pop open the back compartment where the batteries are stored.
  2. Lifting up the keyboard will allow you in to the front compartment. The pressure pads for the keyboard are ingeniously mounted on the back of the motherboard.
It is possible to run Linux on the Revo, as with the 5MX. However, doing this is quite limited by the lack of compactflash.

Source for some of the data: http://www.portal-pda.com/guides/insiderevo/insiderevo.html