Re: Ft 857D with Ham Radio Deluxe
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Most EEPROM's I am familiar with (including those built into microcontrollers) typically have about 10,000 write cycles as their limits. Firmware for EEPROM's/ microcontrollers that I have written make any changes to the EEPROM something the user does and probably occur only a handful of times during the lifetime of the device. I could see that a software-controlled EEPROM programming step could easily exceed the useful limit of number of times to write to an EEPROM.
73, Zack W9SZ
On Mon, May 30, 2022 at 12:43 AM Dave AA6YQ < aa6yq@...> wrote: Yes I did find the HRD notifiocation regarding removing the agc etc commands at Yaesu's request due to them apparently damaging a ram chip (I think).
+ Many years ago, KA7OEI discovered an undocumented pair of instructions for reading and writing the FT-817's EEPROM, and discovered the locations in that EEPROM that controlled radio state not accessible via its documented CAT instruction set:
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+ These undocumented instructions made it possible for transceiver control applications to track and modify that additional radio state.
+ This led to similar discovers for the FT-857 and FT-897.
+ The EEPROM - "Electrically Erasable Programmable Read Only Memory" - used in these radios has a lifetime limit on updates - clearly stated in its spec sheet. Transceiver control applications that used the undocumented instructions to frequently modify that additional radio state eventually wore out the EEPROM, bricking the radio. By then, the EEPROM was no longer available, and Yaesu had exhausted its inventory.
? ? ? 73,
? ? ? ? ? ? ? Dave, AA6YQ
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