diff --git a/src/inc/fileio.plh b/src/inc/fileio.plh
index 46c3841..3cf4a8f 100644
--- a/src/inc/fileio.plh
+++ b/src/inc/fileio.plh
@@ -37,14 +37,23 @@ import fileio
     //
     // File functions
     //
-    predef getpfx, setpfx, getfileinfo
-    predef open, close, read, write, create, destroy, newline
-    //
-    // Block level I/O functions
-    //
-    predef readblock, writeblock
+    struc t_fileio
+        word getpfx
+        word setpfx
+        word getfileinfo
+        word open
+        word close
+        word read
+        word write
+        word create
+        word destroy
+        word newline
+        word readblock
+        word writeblock
+    end
+    word fileio
     //
     // Globally accessible error code
     //
     byte perr
-end
\ No newline at end of file
+end
diff --git a/src/libsrc/fileio.pla b/src/libsrc/fileio.pla
index 91860c6..96d2c29 100644
--- a/src/libsrc/fileio.pla
+++ b/src/libsrc/fileio.pla
@@ -1,12 +1,61 @@
 include "inc/cmdsys.plh"
 //
-// ProDOS error code
+// CFFA1 addresses.
+//
+const CFFA1Dest     = $00
+const CFFA1FileName = $02
+const CFFA1OldName  = $04
+const CFFA1FileType = $06
+const CFFA1AuxType  = $07
+const CFFA1FileSize = $09
+const CFFA1EntryPtr = $0B
+//
+// All our file I/O routines
+//
+struc t_fileio
+    word getpfx
+    word setpfx
+    word getfileinfo
+    word open
+    word close
+    word read
+    word write
+    word create
+    word destroy
+    word newline
+    word readblock
+    word writeblock
+end
+predef a1getpfx, a1setpfx, a1getfileinfo, a1open, a1close, a1read, a1write, a1create, a1destroy
+predef a1newline, a13readblock, a13writeblock
+predef a2getpfx, a23setpfx, a2getfileinfo, a2open, a23close, a23read, a2write, a2create, a23destroy
+predef a23newline, a2readblock, a2writeblock
+predef a3getpfx, a3getfileinfo, a3open, a3write, a3create
+//
+// Exported function table.
+//
+export word fileio[]
+//
+// Platform specific function pointers (default to Apple II).
+//
+word a2io[] = @a2getpfx, @a23setpfx, @a2getfileinfo, @a2open, @a23close, @a23read, @a2write, @a2create, @a23destroy
+word        = @a23newline, @a2readblock, @a2writeblock
+word a3io[] = @a3getpfx, @a23setpfx, @a3getfileinfo, @a3open, @a23close, @a23read, @a3write, @a3create, @a23destroy
+word        = @a23newline, @a13readblock, @a13writeblock
+word a1io[] = @a1getpfx, @a1setpfx, @a1getfileinfo, @a1open, @a1close, @a1read, @a1write, @a1create, @a1destroy
+word        = @a1newline, @a13readblock, @a13writeblock
+//
+// SOS/ProDOS error code
 //
 export byte perr
 //
-// ProDOS routines
+// ProDOS/SOS routines
 //
-export def getpfx(path)
+def a1getpfx(path)
+    ^path = 0
+    return path
+end
+def a2getpfx(path)
     byte params[3]
 
     ^path    = 0
@@ -15,7 +64,19 @@ export def getpfx(path)
     perr     = syscall($C7, @params)
     return path
 end
-export def setpfx(path)
+def a3getpfx(path)
+    byte params[3]
+
+    params.0 = 2
+    params:1 = path
+    params.3 = 64
+    perr     = syscall($C7, @params)
+    return path
+end
+def a1setpfx(path)
+    return path
+end
+def a23setpfx(path)
     byte params[3]
 
     params.0 = 1
@@ -23,7 +84,11 @@ export def setpfx(path)
     perr     = syscall($C6, @params)
     return path
 end
-export def getfileinfo(path, fileinfo)
+def a1getfileinfo(path, fileinfo)
+    perr = $01
+    return perr
+end
+def a2getfileinfo(path, fileinfo)
     byte params[18]
     
     params.0 = 10
@@ -32,7 +97,22 @@ export def getfileinfo(path, fileinfo)
     memcpy(fileinfo, @params + 3, 15)
     return perr
 end
-export def open(path, buf)
+def a3getfileinfo(path, fileinfo)
+    byte params[6]
+    
+    params.0 = 3
+    params:1 = path
+    params:3 = fileinfo
+    params.5 = 15
+    perr     = syscall($C4, @params)
+    return perr
+end
+def a1open(path, buf)
+    *CFFA1FileName = path
+    *CFFA1Dest     = buf
+    return 0
+end
+def a2open(path, buf)
     byte params[6]
 
     params.0 = 3
@@ -42,7 +122,21 @@ export def open(path, buf)
     perr     = syscall($C8, @params)
     return params.5
 end
-export def close(refnum)
+def a3open(path, access)
+    byte params[7]
+
+    params.0 = 4
+    params:1 = path
+    params.3 = 0
+    params:4 = @access
+    params.6 = 1
+    syscall($C8, @params)
+    return params.3
+end
+def a1close(refnum)
+    return perr
+end
+def a23close(refnum)
     byte params[2]
 
     params.0 = 1
@@ -50,7 +144,11 @@ export def close(refnum)
     perr     = syscall($CC, @params)
     return perr
 end
-export def read(refnum, buf, len)
+def a1read(refnum, buf, len)
+    perr = syscall($22) // This reads the entire file on CFFA
+    return perr
+end
+def a23read(refnum, buf, len)
     byte params[8]
 
     params.0 = 4
@@ -61,7 +159,10 @@ export def read(refnum, buf, len)
     perr     = syscall($CA, @params)
     return params:6
 end
-export def write(refnum, buf, len)
+def a1write(refnum, buf, len)
+    return perr
+end
+def a2write(refnum, buf, len)
     byte params[8]
 
     params.0 = 4
@@ -72,7 +173,20 @@ export def write(refnum, buf, len)
     perr     = syscall($CB, @params)
     return params:6
 end
-export def create(path, access, type, aux)
+def a3write(refnum, buff, len)
+    byte params[6]
+
+    params.0 = 3
+    params.1 = refnum
+    params:2 = buff
+    params:4 = len
+    perr     = syscall($CB, @params)
+    return perr
+end
+def a1create(path, access, type, aux)
+    return perr
+end
+def a2create(path, access, type, aux)
     byte params[12]
 
     params.0  = 7
@@ -86,7 +200,23 @@ export def create(path, access, type, aux)
     perr      = syscall($C0, @params)
     return perr
 end
-export def destroy(path)
+def a3create(path, access, type, aux)
+    byte params[6]
+    byte options[4]
+
+    params.0  = 3
+    params:1  = path
+    params:3  = @options
+    params.5  = 3
+    options.0 = type
+    options:1 = aux
+    perr      = syscall($C0, @params)
+    return perr
+end
+def a1destroy(path)
+    return perr
+end
+def a23destroy(path)
     byte params[3]
 
     params.0 = 1
@@ -94,7 +224,10 @@ export def destroy(path)
     perr     = syscall($C1, @params)
     return perr
 end
-export def newline(refnum, emask, nlchar)
+def a1newline(refnum, emask, nlchar)
+    return perr
+end
+def a23newline(refnum, emask, nlchar)
     byte params[4]
 
     params.0 = 3
@@ -104,7 +237,11 @@ export def newline(refnum, emask, nlchar)
     perr     = syscall($C9, @params)
     return perr
 end
-export def readblock(unit, buf, block)
+def a13readblock(unit, buf, block)
+    perr = $27  // IOERR
+    return perr
+end
+def a2readblock(unit, buf, block)
     byte params[6]
     
     params.0 = 3
@@ -114,7 +251,11 @@ export def readblock(unit, buf, block)
     perr     = syscall($80, @params)
     return perr
 end
-export def writeblock(unit, buf, block)
+def a13writeblock(unit, buf, block)
+    perr = $27  // IOERR
+    return perr
+end
+def a2writeblock(unit, buf, block)
     byte params[6]
     
     params.0 = 3
@@ -124,5 +265,16 @@ export def writeblock(unit, buf, block)
     perr     = syscall($81, @params)
     return perr
 end
-
+//
+// Machine specific initialization.
+//
+when MACHID & $C8
+    is $08 // Apple 1
+        memcpy(fileio, a1io, t_fileio)
+        break
+    is $C0 // Apple ///
+        memcpy(fileio, a3io, t_fileio)
+        break
+    otherwise // Apple ][
+wend
 done
diff --git a/src/libsrc/sane.pla b/src/libsrc/sane.pla
index 04c5593..cb0d09c 100644
--- a/src/libsrc/sane.pla
+++ b/src/libsrc/sane.pla
@@ -703,14 +703,14 @@ def loadcode(codefile)
 
     //puts(codefile); puts(":\n")
     pcode = 0
-    ref   = open(codefile, sysbuf)
+    ref   = fileio:open(codefile, sysbuf)
     if ref
         pcode = heapmark
-        read(ref, pcode, 512)
+        fileio:read(ref, pcode, 512)
         //dumpheader(pcode)
         //putname(pcode + segname + 8); putc('='); prword(pcode); putln
-        seglen = read(ref, pcode, (pcode + t_diskinfo)=>codeaddr)
-        close(ref)
+        seglen = fileio:read(ref, pcode, (pcode + t_diskinfo)=>codeaddr)
+        fileio:close(ref)
         if !fp6502 and (MACHID & $30 == $30)
             seglen = fixup(AUXADDR, pcode + seglen - 2) - pcode
             auxmove(AUXADDR, pcode, seglen)
diff --git a/src/samplesrc/fatget.pla b/src/samplesrc/fatget.pla
index 81d9958..5b98d1d 100644
--- a/src/samplesrc/fatget.pla
+++ b/src/samplesrc/fatget.pla
@@ -126,9 +126,9 @@ def fatCopyFrom(src, dst, type, aux)
     //
     // Check if dst already exists
     //
-    ref = open(dst, sysbuf)
+    ref = fileio:open(dst, sysbuf)
     if ref
-        close(ref)
+        fileio:close(ref)
         puts("Overwrite "); puts(dst)
         if not getYN("(Y/N)?")
             heaprelease(freeAddr)
@@ -140,10 +140,10 @@ def fatCopyFrom(src, dst, type, aux)
     //
     // Create dst file
     //
-    if create(dst, $C3, type, aux)
+    if fileio:create(dst, $C3, type, aux)
         puts("Create file error: "); putByte(perr); putln
     fin
-    ref = open(dst, sysbuf)
+    ref = fileio:open(dst, sysbuf)
     if not ref
         puts("Error opening file: "); puts(dst); putln
         puts("Open file error: "); putByte(perr); putln
@@ -156,7 +156,7 @@ def fatCopyFrom(src, dst, type, aux)
         repeat
             copyLen = bigFatRead(copyBuf, COPY_BUF_SIZE)
             if copyLen
-                if write(ref, copyBuf, copyLen) <> copyLen
+                if fileio:write(ref, copyBuf, copyLen) <> copyLen
                     puts("Error writing file:"); puts(dst); putln
                     puts("Write file error: "); putByte(perr); putln
                     copyLen = 0 // Force end of copy
@@ -167,7 +167,7 @@ def fatCopyFrom(src, dst, type, aux)
     else
         puts("Error opening FAT file:"); puts(src); putln
     fin
-    close(ref)
+    fileio:close(ref)
     heaprelease(freeAddr)
 end
 
@@ -180,4 +180,4 @@ if ^arg
 else
     puts("Usage: +FATGET <FAT filename>"); putln
 fin
-done
\ No newline at end of file
+done
diff --git a/src/samplesrc/fatput.pla b/src/samplesrc/fatput.pla
index d16d690..d2d3880 100644
--- a/src/samplesrc/fatput.pla
+++ b/src/samplesrc/fatput.pla
@@ -43,7 +43,7 @@ def mkFatName(proName, fatName)
     word l, n
     byte fileinfo[t_fileinfo]
     
-    if !getfileinfo(proName, @fileinfo)
+    if !fileio:getfileinfo(proName, @fileinfo)
         //
         // Scan backward looking for dir seperator
         //
@@ -110,7 +110,7 @@ def fatCopyTo(src, dst)
         puts("Not enough free memory!\n"); putln
         return -1
     fin
-    ref = open(src, sysbuf)
+    ref = fileio:open(src, sysbuf)
     if not ref
         puts("Error opening file: "); puts(src); putln
         puts("Open file error: "); putByte(perr); putln
@@ -121,7 +121,7 @@ def fatCopyTo(src, dst)
     //
     if sdFAT:fileOpen(dst, O_READ | O_WRITE | O_CREAT)
         repeat
-            copyLen = read(ref, copyBuf, COPY_BUF_SIZE)
+            copyLen = fileio:read(ref, copyBuf, COPY_BUF_SIZE)
             if copyLen
                 copyLen = bigFatWrite(copyBuf, copyLen)
                 if !copyLen
@@ -132,7 +132,7 @@ def fatCopyTo(src, dst)
     else
         puts("Error opening FAT file:"); puts(dst); putln
     fin
-    close(ref)
+    fileio:close(ref)
     heaprelease(freeAddr)
 end
 
@@ -144,4 +144,4 @@ if ^arg
 else
     puts("Usage: +FATPUT <filename>"); putln
 fin
-done
\ No newline at end of file
+done
diff --git a/src/samplesrc/fatreaddsk.pla b/src/samplesrc/fatreaddsk.pla
index b84886f..0cda2a6 100644
--- a/src/samplesrc/fatreaddsk.pla
+++ b/src/samplesrc/fatreaddsk.pla
@@ -107,7 +107,7 @@ def fatReadImage(src, drv, order)
                 ^$24=^$20 // Move cursor to left edge
                 puts("Reading blocks: "); puti(blocknum)
                     for bufblk = 0 to COPY_BLK_CNT
-                        if readblock(drv, inBuf + (bufblk << 9), blocknum + bufblk)
+                        if fileio:readblock(drv, inBuf + (bufblk << 9), blocknum + bufblk)
                             puts("Read disk error: $"); putb(perr); putln
                             break
                         fin
diff --git a/src/samplesrc/fatwritedsk.pla b/src/samplesrc/fatwritedsk.pla
index 5fc8b60..d6e29b4 100644
--- a/src/samplesrc/fatwritedsk.pla
+++ b/src/samplesrc/fatwritedsk.pla
@@ -113,7 +113,7 @@ def fatWriteImage(src, drv, order)
                         trkSecToBlk(inBuf, outBuf)
                     fin
                     for bufblk = 0 to COPY_BLK_CNT
-                        if writeblock(drv, outBuf + (bufblk << 9), blocknum + bufblk)
+                        if fileio:writeblock(drv, outBuf + (bufblk << 9), blocknum + bufblk)
                             puts("Write disk error: $"); putb(perr); putln
                             break
                         fin
diff --git a/src/samplesrc/rod.pla b/src/samplesrc/rod.pla
index 7ce8ee6..f312710 100644
--- a/src/samplesrc/rod.pla
+++ b/src/samplesrc/rod.pla
@@ -263,7 +263,7 @@ when MACHID & $C8
         gotoxy     = @a3gotoxy
         grmode     = @a3grmode
         textmode   = @a3textmode
-        if modaddr(@cmdsys):0 == $0010
+        if modaddr(@cmdsys):0 == $0099
             devcons = modaddr(@cmdsys).5 // devcons variable from cmdsys
         else
             puts(@a3err)
diff --git a/src/vmsrc/a1cmd.pla b/src/vmsrc/a1cmd.pla
index 354ad9e..a353bd6 100755
--- a/src/vmsrc/a1cmd.pla
+++ b/src/vmsrc/a1cmd.pla
@@ -34,7 +34,7 @@ predef syscall(cmd)#1, call(addr,areg,xreg,yreg,status)#1
 predef crout()#0, cout(c)#0, prstr(s)#0, print(i)#0, cin()#1, rdstr(p)#1, toupper(c)#1
 predef markheap()#1, allocheap(size)#1, allocalignheap(size, pow2, freeaddr), releaseheap(newheap)#1, availheap()#1
 predef memset(addr,value,size)#0, memcpy(dst,src,size)#0
-predef uword_isgt(a,b)#1, uword_isge(a,b)#1, uword_islt(a,b)#1, uword_isle(a,b)#1
+predef uword_isgt(a,b)#1, uword_isge(a,b)#1, uword_islt(a,b)#1, uword_isle(a,b)#1, divmod(a,b)#2
 predef loadmod(mod)#1, execmod(modfile)#1, lookupstrmod(str)#1
 //
 // System variables.
@@ -88,6 +88,7 @@ byte uisgtstr[]   = "ISUGT"
 byte uisgestr[]   = "ISUGE"
 byte uisltstr[]   = "ISULT"
 byte uislestr[]   = "ISULE"
+byte divmodstr[]  = "DIVMOD"
 byte loadstr[]    = "MODLOAD"
 byte execstr[]    = "MODEXEC"
 byte modadrstr[]  = "MODADDR"
@@ -112,6 +113,7 @@ word              = @uisgtstr,  @uword_isgt
 word              = @uisgestr,  @uword_isge
 word              = @uisltstr,  @uword_islt
 word              = @uislestr,  @uword_isle
+word              = @divmodstr, @divmod
 word              = @loadstr,   @loadmod
 word              = @execstr,   @execmod
 word              = @modadrstr, @lookupstrmod
@@ -348,6 +350,30 @@ asm uword_islt(a,b)#1
     INX
     RTS
 end
+asm divmod(a,b)#2
+    LDA #>(_divmod-1)
+    PHA
+    LDA #<(_divmod-1)
+    PHA
+    JSR INTERP
+    !BYTE   $0A, $5C    ; MOD, RET
+_divmod DEX
+    LDA DSTL            ; DVDNDL
+    STA ESTKL,X
+    LDA DSTH            ; DVDNDH
+    STA ESTKH,X
+    LSR DVSIGN          ; SIGN(RESULT) = (SIGN(DIVIDEND) + SIGN(DIVISOR)) & 1
+    BCS +
+    RTS
++   LDA #$00
+;   SEC
+    SBC ESTKL,X
+    STA ESTKL,X
+    LDA #$00
+    SBC ESTKH,X
+    STA ESTKH,X
+    RTS
+end
 //
 // Addresses of internal routines.
 //
diff --git a/src/vmsrc/cmd.pla b/src/vmsrc/cmd.pla
index 555ac3d..6d5eb75 100755
--- a/src/vmsrc/cmd.pla
+++ b/src/vmsrc/cmd.pla
@@ -28,7 +28,7 @@ predef syscall(cmd,params)#1, call(addr,areg,xreg,yreg,status)#1
 predef crout()#0, cout(c)#0, prstr(s)#0, print(i)#0, cin()#1, rdstr(p)#1, toupper(c)#1
 predef markheap()#1, allocheap(size)#1, allocalignheap(size, pow2, freeaddr)#1, releaseheap(newheap)#1, availheap()#1
 predef memset(addr,value,size)#0, memcpy(dst,src,size)#0
-predef uword_isgt(a,b)#1, uword_isge(a,b)#1, uword_islt(a,b)#1, uword_isle(a,b)#1
+predef uword_isgt(a,b)#1, uword_isge(a,b)#1, uword_islt(a,b)#1, uword_isle(a,b)#1, divmod(a,b)#2
 predef loadmod(mod)#1, execmod(modfile)#1, lookupstrmod(str)#1
 //
 // System variable.
@@ -65,6 +65,7 @@ byte uisgtstr   = "ISUGT"
 byte uisgestr   = "ISUGE"
 byte uisltstr   = "ISULT"
 byte uislestr   = "ISULE"
+byte divmodstr  = "DIVMOD"
 byte loadstr    = "MODLOAD"
 byte execstr    = "MODEXEC"
 byte modadrstr  = "MODADDR"
@@ -91,6 +92,7 @@ word            = @uisgtstr,  @uword_isgt
 word            = @uisgestr,  @uword_isge
 word            = @uisltstr,  @uword_islt
 word            = @uislestr,  @uword_isle
+word            = @divmodstr, @divmod
 word            = @loadstr,   @loadmod
 word            = @execstr,   @execmod
 word            = @modadrstr, @lookupstrmod
@@ -499,6 +501,30 @@ asm uword_islt(a,b)#1
         INX
         RTS
 end
+asm divmod(a,b)#2
+        LDA     #>(_divmod-1)
+        PHA
+        LDA     #<(_divmod-1)
+        PHA
+        JSR     $03D0           ; CALL DINTERP
+        !BYTE   $0A, $5C        ; MOD, RET
+_divmod DEX
+        LDA     DSTL            ; DVDNDL
+        STA     ESTKL,X
+        LDA     DSTH            ; DVDNDH
+        STA     ESTKH,X
+        LSR     DVSIGN          ; SIGN(RESULT) = (SIGN(DIVIDEND) + SIGN(DIVISOR)) & 1
+        BCS     +
+        RTS
++       LDA     #$00
+;       SEC
+        SBC     ESTKL,X
+        STA     ESTKL,X
+        LDA     #$00
+        SBC     ESTKH,X
+        STA     ESTKH,X
+        RTS
+end
 //
 // Utility routines.
 //
diff --git a/src/vmsrc/plvm01.s b/src/vmsrc/plvm01.s
index 8a83f17..4b7ed50 100644
--- a/src/vmsrc/plvm01.s
+++ b/src/vmsrc/plvm01.s
@@ -138,6 +138,10 @@ DIV     JSR _DIV
 ;* MOD TOS-1 BY TOS
 ;*
 MOD JSR _DIV
+    LDA ESTKL,X     ; SAVE IN CASE OF DIVMOD
+    STA DSTL
+    LDA ESTKH,X
+    STA DSTH
     LDA TMPL        ; REMNDRL
     STA ESTKL,X
     LDA TMPH        ; REMNDRH
diff --git a/src/vmsrc/plvm02.s b/src/vmsrc/plvm02.s
index e3e28ce..c71e00c 100755
--- a/src/vmsrc/plvm02.s
+++ b/src/vmsrc/plvm02.s
@@ -560,6 +560,10 @@ DIV     JSR     _DIV
 ;* MOD TOS-1 BY TOS
 ;*
 MOD     JSR     _DIV
+        LDA     ESTKL,X         ; SAVE IN CASE OF DIVMOD
+        STA     DSTL
+        LDA     ESTKH,X
+        STA     DSTH
         LDA     TMPL            ; REMNDRL
         STA     ESTKL,X
         LDA     TMPH            ; REMNDRH
diff --git a/src/vmsrc/plvm03.s b/src/vmsrc/plvm03.s
index 2a9ccb3..d2b3649 100755
--- a/src/vmsrc/plvm03.s
+++ b/src/vmsrc/plvm03.s
@@ -286,6 +286,10 @@ DIV     JSR     _DIV
 ;* MOD TOS-1 BY TOS
 ;*
 MOD     JSR     _DIV
+        LDA     ESTKL,X         ; SAVE IN CASE OF DIVMOD
+        STA     DSTL
+        LDA     ESTKH,X
+        STA     DSTH
         LDA     TMPL            ; REMNDRL
         STA     ESTKL,X
         LDA     TMPH            ; REMNDRH
diff --git a/src/vmsrc/plvm802.s b/src/vmsrc/plvm802.s
index bc376a5..410f484 100644
--- a/src/vmsrc/plvm802.s
+++ b/src/vmsrc/plvm802.s
@@ -613,6 +613,8 @@ DIV     JSR     _DIV
 MOD     JSR     _DIV
         STA     NOS,S           ; REMNDR
         PLA
+        STA     DST             ; SAVE IN CASE OF DIVMOD
+        STX     DVSIGN
         TXA
         AND     #$0080          ; REMAINDER IS SIGN OF DIVIDEND
         BNE     NEG
diff --git a/src/vmsrc/soscmd.pla b/src/vmsrc/soscmd.pla
index 87802a0..c361c0b 100755
--- a/src/vmsrc/soscmd.pla
+++ b/src/vmsrc/soscmd.pla
@@ -29,7 +29,7 @@ predef syscall(cmd,params)#1, call(addr,areg,xreg,yreg,status)#1
 predef crout()#0, cout(c)#0, prstr(s)#0, print(i)#0, cin()#1, rdstr(p)#1, toupper(c)#1
 predef markheap()#1, allocheap(size)#1, allocalignheap(size, pow2, freeaddr), releaseheap(newheap)#1, availheap()#1
 predef memset(addr,value,size)#0, memcpy(dst,src,size)#0
-predef uword_isgt(a,b)#1, uword_isge(a,b)#1, uword_islt(a,b)#1, uword_isle(a,b)#1
+predef uword_isgt(a,b)#1, uword_isge(a,b)#1, uword_islt(a,b)#1, uword_isle(a,b)#1, divmod(a,b)#2
 predef loadmod(mod)#1, execmod(modfile)#1, lookupstrmod(str)#1
 //
 // System variables.
@@ -83,6 +83,7 @@ byte uisgtstr[]   = "ISUGT"
 byte uisgestr[]   = "ISUGE"
 byte uisltstr[]   = "ISULT"
 byte uislestr[]   = "ISULE"
+byte divmodstr[]  = "DIVMOD"
 byte loadstr[]    = "MODLOAD"
 byte execstr[]    = "MODEXEC"
 byte modadrstr[]  = "MODADDR"
@@ -108,6 +109,7 @@ word              = @uisgtstr,  @uword_isgt
 word              = @uisgestr,  @uword_isge
 word              = @uisltstr,  @uword_islt
 word              = @uislestr,  @uword_isle
+word              = @divmodstr, @divmod
 word              = @loadstr,   @loadmod
 word              = @execstr,   @execmod
 word              = @modadrstr, @lookupstrmod
@@ -232,9 +234,9 @@ asm memcpy(dst,src,size)#0
 ;
 ; FORWARD COPY
 ;
-        LDA     ESTKL-2,X
+        LDA     ESTKL-1,X
         STA     DSTL
-        LDA     ESTKH-2,X
+        LDA     ESTKH-1,X
         STA     DSTH
         LDA     ESTKL-2,X
         STA     SRCL
@@ -410,6 +412,30 @@ asm uword_islt(a,b)#1
         INX
         RTS
 end
+asm divmod(a,b)#2
+        LDA     #>(_divmod-1)
+        PHA
+        LDA     #<(_divmod-1)
+        PHA
+        JSR     INTERP
+        !BYTE   $0A, $5C        ; MOD, RET
+_divmod DEX
+        LDA     DSTL            ; DVDNDL
+        STA     ESTKL,X
+        LDA     DSTH            ; DVDNDH
+        STA     ESTKH,X
+        LSR     DVSIGN          ; SIGN(RESULT) = (SIGN(DIVIDEND) + SIGN(DIVISOR)) & 1
+        BCS     +
+        RTS
++       LDA     #$00
+;       SEC
+        SBC     ESTKL,X
+        STA     ESTKL,X
+        LDA     #$00
+        SBC     ESTKH,X
+        STA     ESTKH,X
+        RTS
+end
 //
 // Addresses of internal routines.
 //
@@ -960,9 +986,9 @@ def loadmod(mod)#1
     if refnum > 0
         rdlen   = read(refnum, @header, 128)
         modsize = header:0
-        moddep  = @header.1
-        defofst = modsize
-        init    = 0
+        //moddep  = @header.1
+        //defofst = modsize
+        //init    = 0
         if rdlen > 4 and header:2 == $DA7F // DAVE+1 = magic number :-)
             //
             // This is an EXTended RELocatable (data+bytecode) module.