diff --git a/asminc/rp6502.inc b/asminc/rp6502.inc
index 816712abb..c3cec2182 100644
--- a/asminc/rp6502.inc
+++ b/asminc/rp6502.inc
@@ -37,6 +37,7 @@ RIA_OP_PHI2               := $02
 RIA_OP_CODEPAGE           := $03
 RIA_OP_LRAND              := $04
 RIA_OP_STDIN_OPT          := $05
+RIA_OP_ERRNO_OPT          := $06
 RIA_OP_CLOCK              := $0F
 RIA_OP_CLOCK_GETRES       := $10
 RIA_OP_CLOCK_GETTIME      := $11
@@ -72,27 +73,3 @@ VIA_PCR         := VIA+$C       ; Peripheral control register
 VIA_IFR         := VIA+$D       ; Interrupt flag register
 VIA_IER         := VIA+$E       ; Interrupt enable register
 VIA_PA2         := VIA+$F       ; Port register A w/o handshake
-
-; Values in ___oserror are the union of these FatFs errors and errno.inc
-.enum
-    FR_OK = 32             ; Succeeded
-    FR_DISK_ERR            ; A hard error occurred in the low level disk I/O layer
-    FR_INT_ERR             ; Assertion failed
-    FR_NOT_READY           ; The physical drive cannot work
-    FR_NO_FILE             ; Could not find the file
-    FR_NO_PATH             ; Could not find the path
-    FR_INVALID_NAME        ; The path name format is invalid
-    FR_DENIED              ; Access denied due to prohibited access or directory full
-    FR_EXIST               ; Access denied due to prohibited access
-    FR_INVALID_OBJECT      ; The file/directory object is invalid
-    FR_WRITE_PROTECTED     ; The physical drive is write protected
-    FR_INVALID_DRIVE       ; The logical drive number is invalid
-    FR_NOT_ENABLED         ; The volume has no work area
-    FR_NO_FILESYSTEM       ; There is no valid FAT volume
-    FR_MKFS_ABORTED        ; The f_mkfs() aborted due to any problem
-    FR_TIMEOUT             ; Could not get a grant to access the volume within defined period
-    FR_LOCKED              ; The operation is rejected according to the file sharing policy
-    FR_NOT_ENOUGH_CORE     ; LFN working buffer could not be allocated
-    FR_TOO_MANY_OPEN_FILES ; Number of open files > FF_FS_LOCK
-    FR_INVALID_PARAMETER   ; Given parameter is invalid
-.endenum
diff --git a/include/rp6502.h b/include/rp6502.h
index 640e4b59b..479621395 100644
--- a/include/rp6502.h
+++ b/include/rp6502.h
@@ -86,11 +86,6 @@ void __fastcall__ ria_set_ax (unsigned int ax);
 int __fastcall__ ria_call_int (unsigned char op);
 long __fastcall__ ria_call_long (unsigned char op);
 
-/* These run _mappederrno() on error */
-
-int __fastcall__ ria_call_int_errno (unsigned char op);
-long __fastcall__ ria_call_long_errno (unsigned char op);
-
 /* OS operation numbers */
 
 #define RIA_OP_EXIT 0xFF
@@ -100,6 +95,7 @@ long __fastcall__ ria_call_long_errno (unsigned char op);
 #define RIA_OP_CODEPAGE 0x03
 #define RIA_OP_LRAND 0x04
 #define RIA_OP_STDIN_OPT 0x05
+#define RIA_OP_ERRNO_OPT 0x06
 #define RIA_OP_CLOCK 0x0F
 #define RIA_OP_CLOCK_GETRES 0x10
 #define RIA_OP_CLOCK_GETTIME 0x11
@@ -124,6 +120,7 @@ int phi2 (void);
 int codepage (int);
 long lrand (void);
 int __fastcall__ stdin_opt (unsigned long ctrl_bits, unsigned char str_length);
+int __fastcall__ errno_opt (unsigned char platform);
 int __fastcall__ read_xstack (void* buf, unsigned count, int fildes);
 int __fastcall__ read_xram (unsigned buf, unsigned count, int fildes);
 int __fastcall__ write_xstack (const void* buf, unsigned count, int fildes);
diff --git a/libsrc/rp6502/close.c b/libsrc/rp6502/close.c
index 9dea5bdc3..1981baaae 100644
--- a/libsrc/rp6502/close.c
+++ b/libsrc/rp6502/close.c
@@ -4,5 +4,5 @@
 int __fastcall__ close (int fd)
 {
     ria_set_ax (fd);
-    return ria_call_int_errno (RIA_OP_CLOSE);
+    return ria_call_int (RIA_OP_CLOSE);
 }
diff --git a/libsrc/rp6502/crt0.s b/libsrc/rp6502/crt0.s
index 32d565fda..5cf63b615 100644
--- a/libsrc/rp6502/crt0.s
+++ b/libsrc/rp6502/crt0.s
@@ -46,6 +46,6 @@ _exit:
     sta RIA_A
     plx
     stx RIA_X
-    lda #$FF     ; exit()
+    lda #RIA_OP_EXIT
     sta RIA_OP
     stp
diff --git a/libsrc/rp6502/errno.s b/libsrc/rp6502/errno.s
new file mode 100644
index 000000000..aef978bfa
--- /dev/null
+++ b/libsrc/rp6502/errno.s
@@ -0,0 +1,28 @@
+;
+; 2003-08-12, Ullrich von Bassewitz
+; 2015-09-24, Greg King
+;
+; extern int __errno;
+; /* Library errors go here. */
+;
+
+        .include        "rp6502.inc"
+        .include        "errno.inc"
+        .export         ___errno, _errno_opt
+        .import         _ria_call_int
+        .constructor    _errno_opt_constructor
+
+; The errno on the RIA is the errno for cc65
+___errno        := RIA_ERRNO
+
+.code
+
+; Request the RIA use cc65 values for RIA_ERRNO
+_errno_opt_constructor:
+        lda #$01 ; 1 = cc65
+
+; int __fastcall__ errno_opt (unsigned char platform);
+_errno_opt:
+        sta RIA_A
+        lda #RIA_OP_ERRNO_OPT
+        jmp _ria_call_int
diff --git a/libsrc/rp6502/gettime.c b/libsrc/rp6502/gettime.c
index ee63c31ec..339ddeadb 100644
--- a/libsrc/rp6502/gettime.c
+++ b/libsrc/rp6502/gettime.c
@@ -5,8 +5,6 @@ extern int __clock_gettimespec (struct timespec* ts, unsigned char op);
 
 int clock_gettime (clockid_t clock_id, struct timespec* tp)
 {
-    (void)clock_id;
-    /* time.s doesn't set the stack value for clock_id (bug?) */
-    ria_set_ax (CLOCK_REALTIME);
+    ria_set_ax (clock_id);
     return __clock_gettimespec (tp, RIA_OP_CLOCK_GETTIME);
 }
diff --git a/libsrc/rp6502/gettimespec.c b/libsrc/rp6502/gettimespec.c
index 4dc3a0db3..5a07a46d8 100644
--- a/libsrc/rp6502/gettimespec.c
+++ b/libsrc/rp6502/gettimespec.c
@@ -4,7 +4,7 @@
 int __clock_gettimespec (struct timespec* ts, unsigned char op)
 /* Internal method shared by clock_getres and clock_gettime. */
 {
-    int ax = ria_call_int_errno (op);
+    int ax = ria_call_int (op);
     if (ax >= 0) {
         ts->tv_sec = ria_pop_long ();
         ts->tv_nsec = ria_pop_long ();
diff --git a/libsrc/rp6502/gettimezone.c b/libsrc/rp6502/gettimezone.c
index 86d0fefcc..4c4584c07 100644
--- a/libsrc/rp6502/gettimezone.c
+++ b/libsrc/rp6502/gettimezone.c
@@ -6,7 +6,7 @@ int clock_gettimezone (time_t time, clockid_t clock_id, struct _timezone* tz)
     int ax;
     ria_set_ax (clock_id);
     ria_push_long (time);
-    ax = ria_call_int_errno (RIA_OP_CLOCK_GETTIMEZONE);
+    ax = ria_call_int (RIA_OP_CLOCK_GETTIMEZONE);
     if (ax >= 0) {
         char i;
         for (i = 0; i < sizeof (struct _timezone); i++) {
diff --git a/libsrc/rp6502/lseek.c b/libsrc/rp6502/lseek.c
index 29506612c..caddb9bf6 100644
--- a/libsrc/rp6502/lseek.c
+++ b/libsrc/rp6502/lseek.c
@@ -7,5 +7,5 @@ off_t __fastcall__ lseek (int fd, off_t offset, int whence)
     ria_push_long (offset);
     ria_push_char (whence);
     ria_set_ax (fd);
-    return ria_call_long_errno (RIA_OP_LSEEK);
+    return ria_call_long (RIA_OP_LSEEK);
 }
diff --git a/libsrc/rp6502/open.c b/libsrc/rp6502/open.c
index 187c57625..5750eb769 100644
--- a/libsrc/rp6502/open.c
+++ b/libsrc/rp6502/open.c
@@ -7,12 +7,12 @@ int __cdecl__ open (const char* name, int flags, ...)
 {
     size_t namelen = strlen (name);
     if (namelen > 255) {
-        RIA.errno_ = EINVAL;
-        return _mappederrno (RIA.errno_);
+        errno = EINVAL;
+        return -1;
     }
     while (namelen) {
         ria_push_char (name[--namelen]);
     }
     ria_set_ax (flags);
-    return ria_call_int_errno (RIA_OP_OPEN);
+    return ria_call_int (RIA_OP_OPEN);
 }
diff --git a/libsrc/rp6502/oserrlist.s b/libsrc/rp6502/oserrlist.s
deleted file mode 100644
index ef322e293..000000000
--- a/libsrc/rp6502/oserrlist.s
+++ /dev/null
@@ -1,86 +0,0 @@
-;
-; 2002-07-18, Ullrich von Bassewitz
-; 2022, ChaN
-; 2023, Rumbledethumps
-;
-; Defines the platform-specific error list.
-;
-; The table is built as a list of entries:
-;
-;       .byte   entrylen
-;       .byte   errorcode
-;       .asciiz errormsg
-;
-; and, terminated by an entry with length zero that is returned if the
-; error code could not be found.
-;
-
-.export __sys_oserrlist
-
-.include "rp6502.inc"
-.include "errno.inc"
-
-;----------------------------------------------------------------------------
-; Macros used to generate the list (may get moved to an include file?)
-
-; Regular entry
-.macro sys_oserr_entry code, msg
-    .local Start, End
-Start:
-    .byte End - Start
-    .byte code
-    .asciiz msg
-End:
-.endmacro
-
-; Sentinel entry
-.macro sys_oserr_sentinel msg
-    .byte 0  ; Length is always zero
-    .byte 0  ; Code is unused
-    .asciiz msg
-.endmacro
-
-;----------------------------------------------------------------------------
-; The error message table
-
-.rodata
-__sys_oserrlist:
-
-    sys_oserr_entry ENOENT                 , "No such file or directory"
-    sys_oserr_entry ENOMEM                 , "Out of memory"
-    sys_oserr_entry EACCES                 , "Permission denied"
-    sys_oserr_entry ENODEV                 , "No such device"
-    sys_oserr_entry EMFILE                 , "Too many open files"
-    sys_oserr_entry EBUSY                  , "Device or resource busy"
-    sys_oserr_entry EINVAL                 , "Invalid argument"
-    sys_oserr_entry ENOSPC                 , "No space left on device"
-    sys_oserr_entry EEXIST                 , "File exists"
-    sys_oserr_entry EAGAIN                 , "Try again"
-    sys_oserr_entry EIO                    , "I/O error"
-    sys_oserr_entry EINTR                  , "Interrupted system call"
-    sys_oserr_entry ENOSYS                 , "Function not implemented"
-    sys_oserr_entry ESPIPE                 , "Illegal seek"
-    sys_oserr_entry ERANGE                 , "Range error"
-    sys_oserr_entry EBADF                  , "Bad file number"
-    sys_oserr_entry ENOEXEC                , "Exec format error"
-    sys_oserr_entry EUNKNOWN               , "Unknown OS specific error"
-    sys_oserr_entry FR_DISK_ERR            , "A hard error occurred in the low level disk I/O layer"
-    sys_oserr_entry FR_INT_ERR             , "Assertion failed"
-    sys_oserr_entry FR_NOT_READY           , "The physical drive cannot work"
-    sys_oserr_entry FR_NO_FILE             , "Could not find the file"
-    sys_oserr_entry FR_NO_PATH             , "Could not find the path"
-    sys_oserr_entry FR_INVALID_NAME        , "The path name format is invalid"
-    sys_oserr_entry FR_DENIED              , "Access denied due to prohibited access or directory full"
-    sys_oserr_entry FR_EXIST               , "Access denied due to prohibited access"
-    sys_oserr_entry FR_INVALID_OBJECT      , "The file/directory object is invalid"
-    sys_oserr_entry FR_WRITE_PROTECTED     , "The physical drive is write protected"
-    sys_oserr_entry FR_INVALID_DRIVE       , "The logical drive number is invalid"
-    sys_oserr_entry FR_NOT_ENABLED         , "The volume has no work area"
-    sys_oserr_entry FR_NO_FILESYSTEM       , "There is no valid FAT volume"
-    sys_oserr_entry FR_MKFS_ABORTED        , "The f_mkfs() aborted due to any problem"
-    sys_oserr_entry FR_TIMEOUT             , "Could not get a grant to access the volume within defined period"
-    sys_oserr_entry FR_LOCKED              , "The operation is rejected according to the file sharing policy"
-    sys_oserr_entry FR_NOT_ENOUGH_CORE     , "LFN working buffer could not be allocated"
-    sys_oserr_entry FR_TOO_MANY_OPEN_FILES , "Number of open files > FF_FS_LOCK"
-    sys_oserr_entry FR_INVALID_PARAMETER   , "Given parameter is invalid"
-    sys_oserr_sentinel                       "Unknown error"
diff --git a/libsrc/rp6502/oserror.s b/libsrc/rp6502/oserror.s
deleted file mode 100644
index 706bcfa65..000000000
--- a/libsrc/rp6502/oserror.s
+++ /dev/null
@@ -1,66 +0,0 @@
-;
-; 2000-05-17, Ullrich von Bassewitz
-; 2022, ChaN
-; 2023, Rumbledethumps
-;
-; int __fastcall__ __osmaperrno (unsigned char oserror);
-;
-; RP6502 will respond with a union of CC65 and FatFs errnos.
-; This will map FatFs errors into the CC65 range for portable code.
-
-EFATFS_START := 32
-
-.include "rp6502.inc"
-.include "errno.inc"
-
-.code
-
-___osmaperrno:
-    cmp #EFATFS_START
-    bmi @L2
-
-    ldx #ErrTabSize
-@L1:
-    cmp ErrTab-2,x      ; Search for the error code
-    beq @L3             ; Jump if found
-    dex
-    dex
-    bne @L1             ; Next entry
-
-; Code not found, return EUNKNOWN
-    lda #<EUNKNOWN
-    ldx #>EUNKNOWN
-@L2:
-    rts
-
-; Found the code
-@L3:
-    lda ErrTab-1,x
-    ldx #$00            ; High byte always zero
-    rts
-
-.rodata
-
-ErrTab:
-
-    .byte FR_DISK_ERR            , EIO       ; A hard error occurred in the low level disk I/O layer
-;   .byte FR_INT_ERR             , EUNKNOWN  ; Assertion failed
-    .byte FR_NOT_READY           , EBUSY     ; The physical drive cannot work
-    .byte FR_NO_FILE             , ENOENT    ; Could not find the file
-    .byte FR_NO_PATH             , ENOENT    ; Could not find the path
-    .byte FR_INVALID_NAME        , EINVAL    ; The path name format is invalid
-    .byte FR_DENIED              , EACCES    ; Access denied due to prohibited access or directory full
-    .byte FR_EXIST               , EEXIST    ; Access denied due to prohibited access
-    .byte FR_INVALID_OBJECT      , EINVAL    ; The file/directory object is invalid
-    .byte FR_WRITE_PROTECTED     , EACCES    ; The physical drive is write protected
-    .byte FR_INVALID_DRIVE       , ENODEV    ; The logical drive number is invalid
-;   .byte FR_NOT_ENABLED         , EUNKNOWN  ; The volume has no work area
-;   .byte FR_NO_FILESYSTEM       , EUNKNOWN  ; There is no valid FAT volume
-;   .byte FR_MKFS_ABORTED        , EUNKNOWN  ; The f_mkfs() aborted due to any problem
-;   .byte FR_TIMEOUT             , EUNKNOWN  ; Could not get a grant to access the volume within defined period
-    .byte FR_LOCKED              , EBUSY     ; The operation is rejected according to the file sharing policy
-    .byte FR_NOT_ENOUGH_CORE     , ENOMEM    ; LFN working buffer could not be allocated
-    .byte FR_TOO_MANY_OPEN_FILES , EMFILE    ; Number of open files > FF_FS_LOCK
-    .byte FR_INVALID_PARAMETER   , EINVAL    ; Given parameter is invalid
-
-ErrTabSize = (* - ErrTab)
diff --git a/libsrc/rp6502/read_xram.c b/libsrc/rp6502/read_xram.c
index f88a036ee..e14ac29d4 100644
--- a/libsrc/rp6502/read_xram.c
+++ b/libsrc/rp6502/read_xram.c
@@ -5,5 +5,5 @@ int __fastcall__ read_xram (unsigned buf, unsigned count, int fildes)
     ria_push_int (buf);
     ria_push_int (count);
     ria_set_ax (fildes);
-    return ria_call_int_errno (RIA_OP_READ_XRAM);
+    return ria_call_int (RIA_OP_READ_XRAM);
 }
diff --git a/libsrc/rp6502/read_xstack.c b/libsrc/rp6502/read_xstack.c
index 70eebad2f..952323f32 100644
--- a/libsrc/rp6502/read_xstack.c
+++ b/libsrc/rp6502/read_xstack.c
@@ -5,7 +5,7 @@ int __fastcall__ read_xstack (void* buf, unsigned count, int fildes)
     int i, ax;
     ria_push_int (count);
     ria_set_ax (fildes);
-    ax = ria_call_int_errno (RIA_OP_READ_XSTACK);
+    ax = ria_call_int (RIA_OP_READ_XSTACK);
     for (i = 0; i < ax; i++) {
         ((char*)buf)[i] = ria_pop_char ();
     }
diff --git a/libsrc/rp6502/remove.s b/libsrc/rp6502/remove.s
new file mode 100644
index 000000000..3bd91001d
--- /dev/null
+++ b/libsrc/rp6502/remove.s
@@ -0,0 +1,14 @@
+;
+; Ullrich von Bassewitz, 2003-08-12
+;
+; int __fastcall__ remove (const char* name);
+;
+
+        .export         _remove
+
+        .import         __sysremove
+
+
+;--------------------------------------------------------------------------
+
+_remove = __sysremove
diff --git a/libsrc/rp6502/rename.s b/libsrc/rp6502/rename.s
new file mode 100644
index 000000000..0b85a6134
--- /dev/null
+++ b/libsrc/rp6502/rename.s
@@ -0,0 +1,14 @@
+;
+; Ullrich von Bassewitz, 2003-08-12
+;
+; int __fastcall__ rename (const char* oldname, const char* newname);
+;
+
+        .export         _rename
+
+        .import         __sysrename
+
+
+;--------------------------------------------------------------------------
+
+_rename = __sysrename
diff --git a/libsrc/rp6502/ria.s b/libsrc/rp6502/ria.s
index 78da4daba..5fb858a03 100644
--- a/libsrc/rp6502/ria.s
+++ b/libsrc/rp6502/ria.s
@@ -9,10 +9,8 @@
 .export _ria_pop_long, _ria_pop_int
 .export _ria_set_axsreg, _ria_set_ax
 .export _ria_call_int, _ria_call_long
-.export _ria_call_int_errno, _ria_call_long_errno
 
-.importzp c_sp, sreg
-.import ___mappederrno, incsp1
+.importzp sreg
 
 .code
 
@@ -69,21 +67,3 @@ _ria_call_long:
     ldy RIA_SREG+1
     sty sreg+1
     rts
-
-; int __fastcall__ ria_call_int_errno(unsigned char op);
-_ria_call_int_errno:
-    sta RIA_OP
-    jsr RIA_SPIN
-    ldx RIA_X
-    bmi ERROR
-    rts
-
-; long __fastcall__ ria_call_long_errno(unsigned char op);
-_ria_call_long_errno:
-    jsr _ria_call_long
-    bmi ERROR
-    rts
-
-ERROR:
-    lda RIA_ERRNO
-    jmp ___mappederrno
diff --git a/libsrc/rp6502/settime.c b/libsrc/rp6502/settime.c
index 1ba1d2e3e..4b7f8c73e 100644
--- a/libsrc/rp6502/settime.c
+++ b/libsrc/rp6502/settime.c
@@ -6,5 +6,5 @@ int clock_settime (clockid_t clock_id, const struct timespec* tp)
     ria_set_ax (clock_id);
     ria_push_long (tp->tv_nsec);
     ria_push_long (tp->tv_sec);
-    return ria_call_int_errno (RIA_OP_CLOCK_SETTIME);
+    return ria_call_int (RIA_OP_CLOCK_SETTIME);
 }
diff --git a/libsrc/rp6502/stdin_opt.c b/libsrc/rp6502/stdin_opt.c
index 69e6f51cd..ddc1869a1 100644
--- a/libsrc/rp6502/stdin_opt.c
+++ b/libsrc/rp6502/stdin_opt.c
@@ -4,5 +4,5 @@ int __fastcall__ stdin_opt (unsigned long ctrl_bits, unsigned char str_length)
 {
     ria_push_long (ctrl_bits);
     ria_set_a (str_length);
-    return ria_call_int_errno (RIA_OP_STDIN_OPT);
+    return ria_call_int (RIA_OP_STDIN_OPT);
 }
diff --git a/libsrc/rp6502/sysremove.c b/libsrc/rp6502/sysremove.c
index 2f1bcadbb..32010d5bf 100644
--- a/libsrc/rp6502/sysremove.c
+++ b/libsrc/rp6502/sysremove.c
@@ -2,16 +2,16 @@
 #include <errno.h>
 #include <string.h>
 
-unsigned char __fastcall__ _sysremove (const char* name)
+int __fastcall__ _sysremove (const char* name)
 {
     size_t namelen;
     namelen = strlen (name);
     if (namelen > 255) {
         RIA.errno_ = EINVAL;
-        return __mappederrno (RIA.errno_);
+        return -1;
     }
     while (namelen) {
         ria_push_char (name[--namelen]);
     }
-    return ria_call_int_errno (RIA_OP_UNLINK);
+    return ria_call_int (RIA_OP_UNLINK);
 }
diff --git a/libsrc/rp6502/sysrename.c b/libsrc/rp6502/sysrename.c
index f61e96a1d..09f971918 100644
--- a/libsrc/rp6502/sysrename.c
+++ b/libsrc/rp6502/sysrename.c
@@ -2,14 +2,14 @@
 #include <errno.h>
 #include <string.h>
 
-unsigned char __fastcall__ _sysrename (const char* oldpath, const char* newpath)
+int __fastcall__ _sysrename (const char* oldpath, const char* newpath)
 {
     size_t oldpathlen, newpathlen;
     oldpathlen = strlen (oldpath);
     newpathlen = strlen (newpath);
     if (oldpathlen + newpathlen > 510) {
-        RIA.errno_ = EINVAL;
-        return __mappederrno (RIA.errno_);
+        errno = EINVAL;
+        return -1;
     }
     while (oldpathlen) {
         ria_push_char (oldpath[--oldpathlen]);
@@ -18,5 +18,5 @@ unsigned char __fastcall__ _sysrename (const char* oldpath, const char* newpath)
     while (newpathlen) {
         ria_push_char (newpath[--newpathlen]);
     }
-    return ria_call_int_errno (RIA_OP_RENAME);
+    return ria_call_int (RIA_OP_RENAME);
 }
diff --git a/libsrc/rp6502/write_xram.c b/libsrc/rp6502/write_xram.c
index 31a553813..7251cdd43 100644
--- a/libsrc/rp6502/write_xram.c
+++ b/libsrc/rp6502/write_xram.c
@@ -5,5 +5,5 @@ int __fastcall__ write_xram (unsigned buf, unsigned count, int fildes)
     ria_push_int (buf);
     ria_push_int (count);
     ria_set_ax (fildes);
-    return ria_call_int_errno (RIA_OP_WRITE_XRAM);
+    return ria_call_int (RIA_OP_WRITE_XRAM);
 }
diff --git a/libsrc/rp6502/write_xstack.c b/libsrc/rp6502/write_xstack.c
index 1df1fd706..98c90c757 100644
--- a/libsrc/rp6502/write_xstack.c
+++ b/libsrc/rp6502/write_xstack.c
@@ -5,12 +5,12 @@ int __fastcall__ write_xstack (const void* buf, unsigned count, int fildes)
 {
     unsigned i;
     if (count > 512) {
-        RIA.errno_ = EINVAL;
-        return __mappederrno (RIA.errno_);
+        errno = EINVAL;
+        return -1;
     }
     for (i = count; i;) {
         ria_push_char (((char*)buf)[--i]);
     }
     ria_set_ax (fildes);
-    return ria_call_int_errno (RIA_OP_WRITE_XSTACK);
+    return ria_call_int (RIA_OP_WRITE_XSTACK);
 }
diff --git a/libsrc/rp6502/xregn.c b/libsrc/rp6502/xregn.c
index ec040be20..eaa6aa7b7 100644
--- a/libsrc/rp6502/xregn.c
+++ b/libsrc/rp6502/xregn.c
@@ -15,5 +15,5 @@ int __cdecl__ xregn (char device, char channel, unsigned char address, unsigned
         RIA.xstack = v;
     }
     va_end (args);
-    return ria_call_int_errno (RIA_OP_XREG);
+    return ria_call_int (RIA_OP_XREG);
 }