I have a HTC TyTN II PDA phone, also known as a HTC Kaiser.
Great little PDA, with a phone, Bluetooth and GPS built-in.
But the speed of it was SLOW.

Oh, what to do?

Well fortunately, there is always the folks over at xda-developers.com, with their collection of custom firmware installs.

Now flashing a HTC with a custom firmware is something HTC do discourage, so they make it difficult.

These are the steps which worked for me

  1. Install Hard-SPL v1, for the HTC Kaiser, available here.
  2. Pick a custom firmware from here.
  3. Read all the information about rom flashing on the “HTC Kaiser Wiki page“.
  4. Flash the firmware.
    (no links, it’s dependant on which rom you select)

Now the above links are specific to the HTC TyTN II, but the xda developers site has plenty of information for other HTC devices.