WP34s flashing procedure

[matthiaspaul]

(02-27-2015 07:12 AM)Dieter Wrote:  

(02-26-2015 10:52 PM)Marcus von Cube Wrote:  This looks overly complicated to me. I've programmed a bunch of calculators for other members of this board the following way:

1. Press and hold ERASE.
2. Press ON on the calculator.
3. Press RESET
4. Press ON again.
   

Steps 1 and 2 are enough to erase the flash and reset the boot bit. Step 3 turns the calculator off, step 4 turns it on again with the boot loader enabled.

Just to be sure: RESET turns the calculator off, and pressing ON in step 4 turns it on again.
Should the display now stay blank or does it show "0.00"?

If the erasure worked and no new firmware was flashed yet, it should stay blank, as there is no longer any firmware code around which could cause the display to show "0.00" - you just erased it.

The default boot loader is stored in ROM, not flash, and thus it cannot be erased. However, the default boot loader is generic to the processor and doesn't know anything about peripherals, therefore, it doesn't know that the processor is running in a calculator and that an LCD is attached, and even if it would, it would not know how to handle it.

Greetings,

Matthias