The built-in self-test (BIOS) ESC-ON

Here is how to use the built-in self test routines of the HP Palmtops:

1. Make sure the Palmtop is switched off and has good batteries
   
   
2. Make sure there is no FLASH-based memory card inserted (this is for safety: Attention: NEVER EVER use the "Plug-in RAM card test", while a Flash (ATA flash, Compact Flash) card is inserted. This test is only meant for SRAM cards and it will destroy flash-based cards (or at least their contents, but it will maybe even render them unusable).
   
   
3. Hold the ESC key pressed and shortly press the "ON" key. The Palmtop will switch on and directly boot into the self-test menu.

Note for Doublespeed-upgraded Palmtops: If you have the doublespeed upgrade installed, the screen might be unreadable due to distorted font, because the doublespeed driver is not loaded and cannot be loaded at that stage. Connecting the Palmtop to an AC adapter might help in this case to make the screen more readable (internally some voltages and thus feequencies might change slightly, that may make a difference). If that doesn't help, you would need to use the test "blindly", as far as this works. E.g. the keyboard test can be used blindly, if you know how it works. A second Palmtop with a readable screen helps in this case - simply do everything on both palmtops in parallel. 

If the screen is readable, and you want to check wether you have a doublespeed-upgraded Palmtop or not, use the "Timers" test:

• If the results are in the 10.000 range, 10.700 to 10,913, it is single speed
• If around the 21400, it is a times2tech exact double speed (31.xxx MHz crystal).
• If around 21840, it is a 32.000 Mhz double speed version.
• There were even faster crystals, e.g. 40MHz, which lead to higher values shown in this test. But they don't work reliably on many units and may make the system instable. 

Note: The keyboard test may need a little explanation: During the test there are numbers displayed that denote the key you need to press in order to test it. The numbers mean: 

First place: key row
Second and third place: key column.
E.g.: 104 means "1st row, 4th column", i.e. "Now press the F2 key".

You are asked to press all keys consecutively, left to right and top to bottom. A high beep means "key OK". A low beep means "You pressed the wrong key" and no beep obviously means "key not pressed". If you pressed the key but don't get a beep, it  thus means "key is bad". ;-)

If you see this "RAM4 bad" message or something similar, you may just have destroyed your flash card with the RAM card test :-( :