diff --git a/libsrc/atari/Makefile b/libsrc/atari/Makefile
index c6fff15a6..43644c686 100644
--- a/libsrc/atari/Makefile
+++ b/libsrc/atari/Makefile
@@ -76,6 +76,7 @@ OBJS = 	_scrsize.o      \
 	dioread.o       \
 	diowrite.o      \
 	diowritev.o     \
+	do_oserr.o      \
 	dosdetect.o     \
 	fdtable.o       \
 	fdtoiocb.o      \
@@ -86,6 +87,7 @@ OBJS = 	_scrsize.o      \
 	gotoy.o         \
 	gotoxy.o        \
 	graphics.o      \
+	inviocb.o       \
 	joy_stddrv.o    \
 	kbhit.o         \
 	lseek.o         \
diff --git a/libsrc/atari/do_oserr.s b/libsrc/atari/do_oserr.s
new file mode 100644
index 000000000..6744b0058
--- /dev/null
+++ b/libsrc/atari/do_oserr.s
@@ -0,0 +1,15 @@
+;
+; this routine updates errno.  do a JMP here right after calling
+; CIOV.	 we expect status in Y.
+; __retminus is a routine with returns AX with $FFFF
+;
+	.include "errno.inc"
+
+	.export __do_oserror, __retminus
+
+__do_oserror:
+	sty	__oserror	; save os dependent error code
+__retminus:
+	lda	#$FF
+	tax			; return -1
+	rts
diff --git a/libsrc/atari/inviocb.s b/libsrc/atari/inviocb.s
new file mode 100644
index 000000000..67a6a7c42
--- /dev/null
+++ b/libsrc/atari/inviocb.s
@@ -0,0 +1,12 @@
+;
+; set EINVAL error code and returns -1
+;
+	.include "errno.inc"
+	.import	__retminus
+
+	.export	__inviocb
+
+__inviocb:
+	lda	#<EINVAL
+	jsr	__seterrno
+	jmp	__retminus	; return -1
diff --git a/libsrc/atari/rwcommon.s b/libsrc/atari/rwcommon.s
index e48963454..349c7be01 100644
--- a/libsrc/atari/rwcommon.s
+++ b/libsrc/atari/rwcommon.s
@@ -5,7 +5,6 @@
 	.include "atari.inc"
 	.include "errno.inc"
 	.import popax
-	.import __oserror
 	.import	fdtoiocb
 
 	.export __rwsetup
@@ -42,23 +41,3 @@ iocberr:pla
 	ldx	#$FF		; indicate error + clear ZF
 	rts
 
-;
-; this routine updates errno.  do a JMP here right after calling
-; CIOV.	 we expect status in Y.
-;
-	.export __do_oserror,__inviocb
-__do_oserror:
-	sty	__oserror	; save os dependent error code
-retminus:
-	lda	#$FF
-	tax			; return -1
-	rts
-
-;
-; sets EINVAL error code and returns -1
-;
-
-__inviocb:
-	lda	#<EINVAL
-	jsr	__seterrno
-	jmp	retminus	; return -1