Hacking fx 7000 G

This is a very old calculator, but it has some interesting features, which are not present on other CASIO types.  It has only 2 KB of RAM, but the address mirroring simulates 4KB RAM, where the higher 2 KB returns always 255 (0xFF).

Map of memory:

A[0] .. A[79] - user memory area, programs, etc.

A[80] .. A[175] - graphic memory buffer

A[176] .. A[191] - ?->X buffer (buffer for input while executing ?->X command)

A[192] .. A[207] - command buffer

A[208] .. A[233] - VIDEO RAM

A[234] .. A[254] - unknown :-(

A[255] - magic variable, similar to A[1024] on fx7700 GB, but it is not so magic.

I found only one feature - after entering 1.1->A[255] calculator switches off. This very usefull for me, because this calculator has a mechanic switch, which is not working in my case:-(.