diff --git a/libsrc/atari/atari.inc b/libsrc/atari/atari.inc
index 68c174250..b260fc0ef 100644
--- a/libsrc/atari/atari.inc
+++ b/libsrc/atari/atari.inc
@@ -118,6 +118,29 @@ BADMOD	= 145		;($91) bad screen mode number error
 FNCNOT	= 146		;($92) function not implemented in handler
 SCRMEM	= 147		;($93) insufficient memory for screen mode
 
+DSKFMT	= 148		;($94) SpartaDOS: urecognized disk format
+INCVER	= 149		;($95) SpartaDOS: disk was made with incompat. version
+DIRNFD	= 150		;($96) SpartaDOS: directory not found
+FEXIST	= 151		;($97) SpartaDOS: file exists
+NOTBIN	= 152		;($98) SpartaDOS: file not binary
+LSYMND	= 154		;($9A) SDX: loader symbol not defined
+BADPRM	= 156		;($9C) SDX: bad parameter
+OUTOFM	= 158		;($9E) SDX: out of memory
+INVDEV	= 160		;($A0) invalid device number
+TMOF	= 161		;($A1) too many open files
+DSKFLL	= 162		;($A2) disk full
+FATLIO	= 163		;($A3) fatal I/O error
+FNMSMT	= 164		;($A4) internal file number mismatch
+INVFNM	= 165		;($A5) invalid file name
+PDLERR	= 166		;($A6) point data length error
+EPERM	= 167		;($A7) permission denied
+DINVCM	= 168		;($A8) command invalid for disk
+DIRFLL	= 169		;($A9) directory full
+FNTFND	= 170		;($AA) file not found
+PNTINV	= 171		;($AB) point invalid
+BADDSK	= 173		;($AD) bad disk
+INCFMT	= 176		;($B0) DOS 3: incompatible file system
+
 ; DCB Device Bus Equates
 
 DISKID	= $31		;##rev2## disk bus ID
diff --git a/libsrc/atari/oserror.s b/libsrc/atari/oserror.s
index dcbe7dbb4..b4d0a48ac 100644
--- a/libsrc/atari/oserror.s
+++ b/libsrc/atari/oserror.s
@@ -49,25 +49,30 @@ maptable:
 	.byte	EIO	;TIMOUT	= 138		;($8A) peripheral device timeout error
 	.byte	EIO	;DNACK	= 139		;($8B) device does not acknowledge command
 	.byte	EIO	;FRMERR	= 140		;($8C) serial bus framing error
-	.byte	EINVAL	;CRSROR	= 141		;($8D) cursor overrange error
+	.byte	EINVAL	;CRSROR	= 141		;($8D) cursor out of range error
 	.byte	EIO	;OVRRUN	= 142		;($8E) serial bus data overrun error
 	.byte	EIO	;CHKERR	= 143		;($8F) serial bus checksum error
-	.byte	EIO	;DERROR	= 144		;($90) device done (operation incomplete)
+	.byte	EIO	;DERROR	= 144		;($90) general device failure
 	.byte	EINVAL	;BADMOD	= 145		;($91) bad screen mode number error
 	.byte	ENOSYS	;FNCNOT	= 146		;($92) function not implemented in handler
 	.byte	ENOMEM	;SCRMEM	= 147		;($93) insufficient memory for screen mode
 ; codes below taken from "Mein Atari Computer" (german version of "Your Atari Computer")
-	.byte	EUNKNOWN	; 148 - haven't found documentation
-	.byte	EUNKNOWN	; 149 - haven't found documentation
+; also SpartaDOS codes from http://www.atari-central.com/programming/cio_errors.txt
+	.byte	EUNKNOWN	; 148 - [SpartaDOS] unrecognized disk format
+	.byte	EUNKNOWN	; 149 - [SpartaDOS] disk created by incompatible version of SD
 	.byte	EBUSY		; 150 - serial port already open
+				;       [SpartaDOS] directory not found
 	.byte	EACCES		; 151 - concurrent mode I/O not enabled (serial)
+				;       [SpartaDOS] file exists
 	.byte	EINVAL		; 152 - invalid buffer address for concurrent mode
+				;       [SpartaDOS] not binary format
 	.byte	EAGAIN		; 153 - concurrent mode enabled (and another access tried)
 	.byte	EACCES		; 154 - concurrent mode I/O not active (serial)
+				;       [SpartaDOS X] loader symbol not defined
 	.byte	EUNKNOWN	; 155 - haven't found documentation
-	.byte	EUNKNOWN	; 156 - haven't found documentation
+	.byte	EUNKNOWN	; 156 - [SpartaDOS X] bad parameter
 	.byte	EUNKNOWN	; 157 - haven't found documentation
-	.byte	EUNKNOWN	; 158 - haven't found documentation
+	.byte	EUNKNOWN	; 158 - [SpartaDOS X] out of memory
 	.byte	EUNKNOWN	; 159 - haven't found documentation
 	.byte	ENOENT		; 160 - drive number error (DOS)
 	.byte	EMFILE		; 161 - too many open files
@@ -77,9 +82,14 @@ maptable:
 	.byte	ENOENT		; 165 - invalid file name (e.g. lowercase)
 	.byte	ESPIPE		; 166 - point data length error
 	.byte	EACCES		; 167 - file locked (read-only)
-	.byte	ENOSYS		; 168 - command invalid
+	.byte	ENOSYS		; 168 - command invalid for disk
 	.byte	ENOSPC		; 169 - directory full
 	.byte	ENOENT		; 170 - file not found
 	.byte	ESPIPE		; 171 - point command invalid
+	.byte	EUNKNOWN	; 172 - haven't found documentation
+	.byte	EUNKNOWN	; 173 - bad disk - format couldn't complete
+	.byte	EUNKNOWN	; 174 - haven't found documentation
+	.byte	EUNKNOWN	; 175 - haven't found documentation
+	.byte	EUNKNOWN	; 176 - [DOS 3] incompatible file system
 
 MAX_OSERR_VAL = (* - maptable)