;;rotasciiencrypt
;;Encrypts a string in rot-x (uses $00 to $EF)
;;Inputs:
;; HL: string pointer
;; A: x
;;Notes:
;; Changes string in place.
rotasciiencrypt:
 push hl
  push bc
   ld c, 0
   ld c, a
rotasciiencryptLoop:
   ld a, (hl)
   cp 0
   jr z, rotasciiencryptEnd
   add a, c
   cp 0
   jr nz, rotasciiencryptLd
   inc a
rotasciiencryptLd:
   ld (hl), a
   inc hl
   cp a, $EF
   jr c, rotasciiencryptLoop
   dec hl
   sub a, $0F
   ld (hl), a
   inc hl
   jr rotasciiencryptLoop
rotasciiencryptEnd:
   ld (hl), $00
  pop bc
 pop hl
 ret