8-bit Sine and Cosine (LUT)

Sine:
;Inputs:
;     A is a signed 8-bit value
;Output:
;     BC is the result (B is either FF or 00)
;Notes: I use this in Grammer, so certain things are here to work with Grammer and no other reason.
;       To compute cosine, just add 40h to the input.
 ld d,a
 bit 6,a
 jr z,$+5
   cpl
   xor 80h
 and 63
 ld c,a
 ld hl,sinTable
 ld b,0
 add hl,bc
 ld c,(hl)
 rlc d
 ret nc        ;123
 xor a
 sub c
 ld c,a
 sbc a,a
 sub b
 ld b,a
 ret
sinTable:
 .db 0,3,6,9,13,16,19,22,25,28,31,34,37,40,43,46
 .db 49,52,55,58,60,63,66,68,71,74,76,79,81,84,86,88
 .db 91,93,95,97,99,101,103,105,106,108,110,111,113,114,116,117
 .db 118,119,121,122,122,123,124,125,126,126,127,127,127,128,128,128