ROMWBW Extensions

D.     d --                      display d signed
D+     d1 d2 -- d1+d2          Add double numbers
2>R    d --                                2 to R
2R>    d --                        fetch 2 from R
M*/    d1 n2 u3 --  d=(d1*n2)/u3  
                       double precision mult. div
API    hl de bc n -- hl de bc af 
                          execute ROMWBW API Call
P!     n p --          write byte n to i/o port p
P@     p -- n         read byte n from i/o port p