post_office_read
data = post_office_read(zr, 0, 3) & 0xff;
data = post_office_read(zr, 0, reg & 0x03) & 0xff; // reg. LOWBYTES + read
data = post_office_read(zr, 2, reg & 0x03) & 0xff; // read
int post_office_read(struct zoran *zr, unsigned int guest, unsigned int reg);