Help, who can reverse compile 68HC11 firmware internally? I encountered difficu

[DavidAlfa]

SRAM was not cheap back in the day, so it must be there for something  .
I guess it uses indirect addressing, and the PAL does the remapping.
I found nothing accessing the INIT register (0x103D), so the CPU must be using the default settings.
But the PAL code is really confusing.

[daisizhou]

Regarding the A16ROM and A17ROM signals, they are connected to the 22v10 (PLD chip), but they are not actually used internally in the software, Perhaps it was connected in advance in order to use larger ROM capacity in the future?

I enlarged and analyzed the physical circuit image,Found channel A0-A12 of RAM, which looks very similar to the image.
And I found a resistor on pins 23 and 24 of the PLD chip, at least something that looks like an 0805 chip resistor

[DavidAlfa]

It's just a pullup.