Help, can I find the calibration method by reading the firmware in reverse?

[daisizhou]

https://youtu.be/Q-rE7eNqoPc
Finally, I entered the calibration mode, but I still don't know how to calibrate.
Some new items appear on the menu. I don't know what they are for

[pcprogrammer]

Since the clock is set, you should use another key to continue with calibration. "ESC" which means escape, brings you back to the previous or main menu. Try the "ENT" key and see what happens.

[abyrvalg]

There should be 5 calibration steps:
- 454a SYSTEM OFFSET CALIBRATION
- 454a THERMAL CONVERTER NULL
- AMP CALIBRATION: GAIN=A
- AMP CALIBRATION: GAIN=C
- AMP CALIBRATION: GAIN=D

For first two it just asks "Make sure amp input voltage is zero. Press any key" and does the rest on it's own.
For AMPs it displays some TARGET and ACTUAL voltages and allows to adjust an offset. The goal is to make ACTUAL matching the TARGET I guess. Perhaps you need to apply real precise voltage matching the TARGET to some input during that.

[daisizhou]

Do I need to buy new AT28C64B and M27C1001 chips? Because I'm worried that I will modify the data incorrectly without knowing it.
Although I have backed up AT28C64B and M27C1001, the initial firmware.
I'm worried about the calibration data being modified incorrectly.
The following video shows me entering the "Hardware" option
https://youtu.be/AydYXA4zk-M

This is a video for further testing--->https://youtu.be/W8a2OTjN2-g

[daisizhou]

Do I need to buy new AT28C64B and M27C1001 chips? Because I'm worried that I will modify the data incorrectly without knowing it.
Because I am not sure whether the calibration data will be modified after pressing "ENT" to enter

[abyrvalg]

You don’t need new chips. M27C1001 content never changes in the system (it requires UV erase and high voltage to reprogram). The calibration will be saved into AT28C64B, but you have a backup already (and a prommer used to read it), so it can be restored at any time.

[daisizhou]

OK, I will try to enter the "Calibration" menu to view, please wait for my video

[daisizhou]

Thanks for your help, I have completed the calibration of the host.
I took a video and hope it can be used as a reference for friends who are still using it.
https://youtu.be/abGKWQjHHTk?si=A_2VoX92oenl3gwu

I want to know how these modules work.
In the system menu "auxiliary",It seems that these modules communicate with the host through a DB15 interface.
If you can find a clue in the firmware please let me know, thanks for your help

manual------>http://frankshospitalworkshop.com/equipment/documents/workshop_equipment/manuals/DNI%20Nevada%20402A%20ESU%20Tester%20-%20User%20manual.pdf