sin88 (eZ80 optimized)

cos88:
    ld de,40h
    add hl,de
sin88:
;This computes sin(2pi*x/256), where
;x=H.L is an 8.8 fixed point number
;Output is H.L
;when l>=128, just negate the output.
    ld a,l
    add a,a
    push af
    jp p,$+5
    neg
    cp 124
    ld hl,256
    jr nc,+_
    rrca
    sbc hl,hl
    ld l,a
    ex de,hl
    ld hl,sinLUT
    add hl,de
    ld e,(hl)
    ex de,hl
_:
    pop af
    ret nc
    ex de,hl
    or a
    sbc hl,hl
    sbc hl,de
    ret
sinLUT:
.db 0,6,13,19,25,31,38,44,50,56,62,68,74,80,86,92
.db 98,104,109,115,121,126,132,137,142,147,152,157,162,167,172,177
.db 181,185,190,194,198,202,206,209,213,216,220,223,226,229,231,234
.db 237,239,241,243,245,247,248,250,251,252,253,254,255,255