1 ; Fast RND
                              2 ;
                              3 ; An 8-bit pseudo-random number generator,
                              4 ; using a similar method to the Spectrum ROM,
                              5 ; - without the overhead of the Spectrum ROM.
                              6 ;
                              7 ; R = random number seed
                              8 ; an integer in the range [1, 256]
                              9 ;
                             10 ; R -> (33*R) mod 257
                             11 ;
                             12 ; S = R - 1
                             13 ; an 8-bit unsigned integer
                             14 
   0000                      15 _random::
   0000 3Ar00r00      [13]   16 	ld a, (_seed)
   0003 47            [ 4]   17 	ld b, a 
                             18 
   0004 0F            [ 4]   19 	rrca ; multiply by 32
   0005 0F            [ 4]   20 	rrca
   0006 0F            [ 4]   21 	rrca
   0007 EE 1F         [ 7]   22 	xor #0x1f
                             23 
   0009 80            [ 4]   24 	add a, b
   000A DE FF         [ 7]   25 	sbc a, #255 ; carry
                             26 
   000C 32r00r00      [13]   27 	ld (_seed), a
   000F 6F            [ 4]   28 	ld l, a
   0010 C9            [10]   29 	ret