0b11100 CONSTANT X 0b01000 CONSTANT Y 0b00000 CONSTANT Z
0b11101 CONSTANT X+ 0b11001 CONSTANT Y+ 0b10001 CONSTANT Z+
0b11110 CONSTANT -X 0b11010 CONSTANT -Y 0b10010 CONSTANT -Z
: _ldst ( Rd XYZ op ) SWAP DUP 0x10 AND 8 LSHIFT SWAP 0xf AND
    OR OR ( Rd op' ) SWAP _Rdp A,, ;
: LD, 0x8000 _ldst ; : ST, SWAP 0x8200 _ldst ;
