Z80 Routines:Sound:Beep

From WikiTI
Revision as of 04:36, 13 July 2005 by Guillaumeh (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

By Joe Wingbermuehle (joewing@calc.org). This routine was written for the ZLib library for the SOS shell.

;---------= Make a sound =---------
; c=frequency, b=duration
beep:	di
	ld	e,$D0
beepl1:	ld	a,c
beepl2:	dec	a
	jr	nz,beepl2
	ld	a,e
	xor	%00000011
	ld	e,a
	out	(0),a
	djnz	beepl1
	ei
error:	ret