diff --git a/libsrc/atari/dioread.s b/libsrc/atari/dioread.s
new file mode 100644
index 000000000..06ea0d484
--- /dev/null
+++ b/libsrc/atari/dioread.s
@@ -0,0 +1,55 @@
+;
+; Christian Groessler, October 2000
+;
+; this file provides the _dio_read function
+;
+; unsigned char __fastcall__ _dio_read(_driveid_t drive_id, _sectnum_t sect_num, void *buffer);
+; _driveid_t - 8bit
+; _sectnum_t - 16bit
+;
+
+
+ 	.export		__dio_read
+	.import		popa,popax
+	.include	"atari.inc"
+
+.proc	__dio_read
+
+	sta	DBUFLO		; set buffer address into DCB
+	stx	DBUFHI
+	jsr	popax
+	sta	DAUX1		; set sector #
+	stx	DAUX2
+	jsr	popa
+	cmp	#16
+	bcs	_inv_dev	; invalid device #
+	adc	#1
+	sta	DUNIT		; unit number (d1,d2,d3,...)
+	lda	#$31		; D1 (drive_id == 0) has id $31
+	sta	DDEVIC
+	lda	#0
+	sta	DBYTHI		; high byte of bytes to transfer
+	lda	#%01000000	; indicate i/o direction (read)
+	sta	DSTATS
+	lda	#15
+	sta	DTIMLO		; value got from DOS source
+	lda	#128
+	sta	DBYTLO		; low byte of bytes to transfer	
+	lda	#SIO_READ	; read sector
+	sta	DCOMND
+
+	jsr	SIOV		; execute
+
+	ldx	#0
+	lda	DSTATS
+	bmi	_req_err	; error occurred
+	txa			; no error occurred
+_req_err:
+	rts
+
+_inv_dev:
+	ldx	#0
+	lda	#NONDEV		; non-existent device error
+	rts
+
+.endproc
diff --git a/libsrc/atari/diowrite.s b/libsrc/atari/diowrite.s
new file mode 100644
index 000000000..6c037f379
--- /dev/null
+++ b/libsrc/atari/diowrite.s
@@ -0,0 +1,55 @@
+;
+; Christian Groessler, October 2000
+;
+; this file provides the _dio_write function
+;
+; unsigned char __fastcall__ _dio_write(_driveid_t drive_id, _sectnum_t sect_num, void *buffer);
+; _driveid_t - 8bit
+; _sectnum_t - 16bit
+;
+
+
+ 	.export		__dio_write
+	.import		popa,popax
+	.include	"atari.inc"
+
+.proc	__dio_write
+
+	sta	DBUFLO		; set buffer address into DCB
+	stx	DBUFHI
+	jsr	popax
+	sta	DAUX1		; set sector #
+	stx	DAUX2
+	jsr	popa
+	cmp	#16
+	bcs	_inv_dev	; invalid device #
+	adc	#1
+	sta	DUNIT		; unit number (d1,d2,d3,...)
+	lda	#$31		; D1 (drive_id == 0) has id $31
+	sta	DDEVIC
+	lda	#0
+	sta	DBYTHI		; high byte of bytes to transfer
+	lda	#%10000000	; indicate i/o direction (write)
+	sta	DSTATS
+	lda	#15
+	sta	DTIMLO		; value got from DOS source
+	lda	#128
+	sta	DBYTLO		; low byte of bytes to transfer	
+	lda	#SIO_WRITE	; write sector
+	sta	DCOMND
+
+	jsr	SIOV		; execute
+
+	ldx	#0
+	lda	DSTATS
+	bmi	_req_err	; error occurred
+	txa			; no error occurred
+_req_err:
+	rts
+
+_inv_dev:
+	ldx	#0
+	lda	#NONDEV		; non-existent device error
+	rts
+
+.endproc