Casio Cassiopeia E-700WE is the first PDA I bought back in 2001 or 2002. It runs Pocket PC 2000, has MIPS 150Mhz CPU, and 32MB RAM.
I used to play lots of music on this device, and used it when I cycled about 40km in Tokyo. I used to have an external charger I made, having 2500mAh of battery. E-700WE is probably the best PDA I will ever have, and is a treasure.
The Cassiopeia E-700WE is a limited color edition, the regular ones were named E-700.
The E-700WE does not make you think it runs on a mere 150Mhz CPU.
Get a English version of E-700 dubbed EM-500 from the link below!