Another stupid flashing cable question HP-30b / HP-15C CE

[Maximilian Hohmann]

Hello!

(10-01-2024 05:47 PM)AnnoyedOne Wrote:  I haven't given up--yet

Very good - I appreciate that!

(10-01-2024 05:47 PM)AnnoyedOne Wrote:  The HP-20B "development kit" ... "HP20b original ROM.bin"

Thanks for the hint, I overlooked that.

(10-01-2024 05:47 PM)AnnoyedOne Wrote:  Have you tried flashing that to get your 20B's functional again?

Just tried it now, two or three times with each of my two HP-20b test objects, using the wp34sflash.app on my MacBook pro. The flashing procedure runs through each time and produces the same error message each time (see below). The calculators however work perfectly well in their native HP-20b mode after flashing despite the error message and pass their self-tests.
Very strange! This means that the cable, the flashing software and the USB-serial adapter all seem to work fine. But why is it not able to install the WP34s / WP31s firmware?

Regards
Max