diff --git a/.gitignore b/.gitignore
index c6127b3..d54ffb8 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,6 @@
+# Vim swap files
+*.swp
+
 # Prerequisites
 *.d
 
diff --git a/Makefile b/Makefile
index 7a45122..a4c1c40 100644
--- a/Makefile
+++ b/Makefile
@@ -1,44 +1,30 @@
-# Builds copy command
-
-# Requirements:
-# 1. Gmake must be used.
-# 2. The cc65 compiler must be properly setup.
-
-ifndef CC65_TARGET
-	CC65_TARGET:=apple2enh
+# Compiles with https://www.brutaldeluxe.fr/products/crossdevtools/merlin/
+#
+ifeq ($(OS),Windows_NT)
+    MERLIN_DIR=C:/opt/Merlin32_v1.0
+    MERLIN_LIB=$(MERLIN_DIR)/Library
+    MERLIN=$(MERLIN_DIR)/Windows/Merlin32
+    RM=del /s
+else
+    MERLIN_DIR=$(HOME)/opt/Merlin32_v1.0
+    MERLIN_LIB=$(MERLIN_DIR)/Library
+    MERLIN=$(MERLIN_DIR)/Linux64/Merlin32
+    RM=rm -f
 endif
 
-CC=cl65
-CFLAGS=-O -t $(CC65_TARGET) -DTRACE
-LDFLAGS=-t $(CC65_TARGET)
-PGM=copy
-DISK_VOL=$(PGM)
-DISK=$(DISK_VOL).dsk
 AC=java -jar AppleCommander-ac-1.4.0.jar
-SYS_LOAD_ADDR=0x2000
-BIN_LOAD_ADDR=0x0803
-BASIC_AUX_TYPE=0x0801
-READ_TIME_LOAD_ADDR=0x0260
-MKDISK=$(AC) -pro140 $(DISK) $(DISK_VOL)
+SRC=copy.s
+PGM=copy
+VOL=$(PGM)
+DSK=$(PGM).dsk
 
-########################################
+$(DSK): $(PGM)
+	$(AC) -pro140 $(DSK) $(VOL)
+	$(AC) -p $(DSK) $(PGM) SYS < $(PGM)
 
-all: $(DISK)
-
-$(DISK): $(PGM) 
-	$(RM) $(DISK)
-	$(AC) -pro140 $(DISK) $(DISK_VOL)
-	$(AC) -as $(DISK) $(PGM) BIN < $(PGM)
-
-$(PGM): online.o $(PGM).o
-	$(CC) $(LDFLAGS) -o $@ $^
-
-$(PGM).o: $(PGM).c
-	$(CC) $(CFLAGS) $^
-
-online.o: online.c
-	$(CC) $(CFLAGS) $^
+$(PGM): $(SRC)
+	$(MERLIN) $(MERLIN_LIB) $(SRC)
 
 clean:
-	$(RM) *.o $(PGM) $(DISK)
+	$(RM) $(DSK) $(PGM)
 
diff --git a/Makefile.onl b/Makefile.onl
new file mode 100644
index 0000000..73294b7
--- /dev/null
+++ b/Makefile.onl
@@ -0,0 +1,42 @@
+# Builds online
+
+# Requirements:
+# 1. Gmake must be used.
+# 2. The cc65 compiler must be properly setup.
+
+ifndef CC65_TARGET
+	CC65_TARGET:=apple2enh
+endif
+
+CC=cl65
+CFLAGS=-O -t $(CC65_TARGET) -DTRACE
+# The -S $6000 makes the start address $6000 so that both hi-res
+# pages are available.
+LDFLAGS=-t $(CC65_TARGET) -u __EXEHDR__ --start-addr 0x6000
+PGM=online
+DISK_VOL=$(PGM)
+DISK=$(DISK_VOL).dsk
+BASIC_AUX_TYPE=0x0801
+READ_TIME_LOAD_ADDR=0x0260
+AC=java -jar AppleCommander-ac-1.4.0.jar
+SYS_LOAD_ADDR=0x2000
+BIN_LOAD_ADDR=0x0803
+
+########################################
+
+all: $(DISK)
+
+$(DISK): $(PGM) 
+	$(RM) $(DISK)
+	$(AC) -pro140 $(DISK) $(DISK_VOL)
+	$(AC) -as $(DISK) $(PGM) BIN < $(PGM)
+
+$(PGM): $(PGM).o
+	$(CC) $(LDFLAGS) -o $@ $^
+
+$(PGM).o: $(PGM).c
+	$(CC) $(CFLAGS) $(PGM).c
+
+clean:
+	$(RM) *.o $(PGM) $(DISK)
+
diff --git a/copy.s b/copy.s
new file mode 100644
index 0000000..67d7afa
--- /dev/null
+++ b/copy.s
@@ -0,0 +1,170 @@
+********************************
+*                              *
+* COPY - COPIES FILES          *
+*                              *
+* AUTHOR:  BILL CHATFIELD      *
+* LICENSE: GPL2                *
+*                              *
+********************************
+
+               org  $2000
+               dsk  copy
+               typ  $ff             ;System type
+
+********************************
+*                              *
+* CONSTANTS                    *
+*                              *
+********************************
+
+IN          equ $0200
+RDKEY          equ  $FD0C           ;Reads 1 character
+GETLN       equ $fd6a
+GETLN1         equ  $fd6f           ;Get line, no prompt
+CROUT          equ  $FD8E           ;Output carriage return
+COUT           equ  $FDED           ;Output a character
+PRBYTE         equ  $FDDA           ;Print error message
+BELL           equ  $FF3A           ;Subroutine to beep
+PRODOS_MLI     equ  $bf00           ;Address for MLI subroutine entry point
+SET_FILE_INFO  equ  $c3             ;Code for system call
+GET_FILE_INFO  equ  $c4             ;Code for system call
+ON_LINE        equ  $c5             ;Id for ON_LINE MLI system call
+
+********************************
+*                              *
+* puts                         *
+*                              *
+********************************
+
+puts        mac
+            tya                     ;Preserve y
+            pha
+            ldy     #0              ;Prepare loop index
+]nextchar   lda     ]1,y            ;Load a character
+            cmp     #0              ;Check for end of string
+            beq     finish
+            jsr     COUT
+            iny
+            jmp     ]nextchar
+finish      pla                     ;Restore y
+            tay
+            <<<
+
+********************************
+*                              *
+* movb - Move byte             *
+*                              *
+********************************
+
+movb        mac
+            lda     ]2
+            sta     ]1
+            <<<
+
+********************************
+*                              *
+* mova - Move addrs            *
+*                              *
+********************************
+
+mova        mac
+            lda     src
+            sta     dest
+            lda     src+1
+            sta     dest+1
+            <<<
+
+********************************
+*                              *
+* Main                         *
+*                              *
+********************************
+
+main
+
+; Read in source file name and store it in srcFile
+
+getSource   puts    srcPrompt
+            jsr     GETLN1
+            cpx     #64
+            bpl     getSource
+
+            stx     srcFileLength
+            ldx     #0
+srcChar     lda     IN,x
+            sta     srcFileChars,x
+            inx
+            cpx     srcFileLength
+            bmi     srcChar
+
+; Set fiParamCount parameter
+
+            lda     #$a
+            sta     fiParamCount
+
+; Set fiPathName parameter
+
+            lda     #<srcFile
+            sta     fiPathName
+            lda     #>srcFile
+            sta     fiPathName+1
+
+            jsr     PRODOS_MLI          ;Call MLI subroutine
+            db      GET_FILE_INFO       ;Identify the system call
+            da      fileInfo            ;Address of system call args
+            beq     cont1               ;Returns 0 on success
+            jsr     handleError
+cont1
+
+; Read in destination file name and store it in dstFile
+
+getDest     puts    dstPrompt
+            jsr     GETLN1
+            cpx     #64
+            bpl     getDest  
+
+            stx     dstFileLength
+            ldx     #0
+dstChar     lda     IN,x
+            sta     dstFileChars,x
+            inx
+            cpx     dstFileLength
+            bmi     dstChar
+
+            rts
+
+********************************
+*                              *
+* Data                         *
+*                              *
+********************************
+
+srcPrompt       asc "File to copy: ",00
+srcFile
+srcFileLength   db  0               ;Length byte
+srcFileChars    ds  64              ;Characters of srcFile
+
+dstFile
+dstFileLength   db  0               ;Length byte
+dstFileChars    ds  64              ;Characters of dstFile
+
+onlineVols      ds  256             ;Space for 16 disk vol records
+
+onlineArgs
+olParamCount    db  2               ;Parameter count
+olUnitNumber    db  0               ;Unit number, 0=all
+olBufferAddr    da  onlineVols      ;Address of output buffer
+
+fileInfo
+fiParamCount    db  0
+fiPathName      da  0
+fiAccess        db  0
+fiFileType      db  0
+fiAuxType       dw  0
+fiStorageType   db  0
+fiBlocksUsed    dw  0
+fiModDate       dw  0
+fiModTime       dw  0
+fiCreateDate    dw  0
+fiCreateTime    dw  0
+
diff --git a/errorhandler.s b/errorhandler.s
new file mode 100644
index 0000000..d5908b5
--- /dev/null
+++ b/errorhandler.s
@@ -0,0 +1,160 @@
+
+ENOERR         equ  $00
+EBADCALLNUM    equ  $01
+EBADPARMCNT    equ  $04
+EINTRTBLFULL   equ  $25
+EIO            equ  $27
+ENODEV         equ  $28
+EROFS          equ  $b2
+EDISKSWITCHED  equ  $2e
+EINVALIDPATH   equ  $40
+EMAXFILES      equ  $42
+EINVALIDREF    equ  $43
+EDIRNOTFOUND   equ  $44
+EVOLNOTFOUND   equ  $45
+ENOENT         equ  $46
+EDUPFILENAME   equ  $47
+EVOLFULL       equ  $48
+EVOLDIRFULL    equ  $49
+EFILEFORMAT    equ  $4a
+ESTRGTYPE      equ  $4b
+EEOF           equ  $4c
+EOUTOFRANGE    equ  $4d
+EFILELOCKED    equ  $4e
+EFILEISOPEN    equ  $50
+EDAMAGEDDIR    equ  $51
+ENOTPRODOS     equ  $52
+EBADPARAM      equ  $53
+EVCBTBLFULL    equ  $55
+EBADADDR       equ  $56
+EDUPVOL        equ  $57
+EDAMAGEDFILE   equ  $5a
+
+handleError
+    sta errorCode
+    ldx #0
+    ldy #0
+nextCode    
+    lda errorCodes,x
+    cmp errorCode
+    beq foundCode
+    inx
+    iny
+    iny
+    cpy errorCodeCount
+    bmi nextCode
+unknownCode
+    puts errorLabel
+    lda errorCode
+    jsr PRBYTE
+    jsr CROUT
+    rts
+foundCode   
+    lda errorMessages,y
+    sta errorMessage
+    iny
+    lda errorMessage,y
+    sta errorMessage+1
+    puts (errorMessage)
+    rts 
+
+errorCode       db  0
+errorMessage    da  0
+errorLabel      asc "Error ",00
+
+EMNOERR          ASC "No error",00                           ;$00
+EMBADCALLNUM     ASC "Bad system call number",00             ;$01
+EMBADPARMCNT     ASC "Bad system call parameter count",00    ;$04
+EMINTRTBLFULL    ASC "Interrupt table full",00               ;$25
+EMIO             ASC "I/O error",00                          ;$27
+EMNODEV          ASC "No device connected",00                ;$28
+EMROFS           ASC "Disk write protected",00               ;$b2
+EMDISKSWITCHED   ASC "Disk switched",00   ;$2e
+EMINVALIDPATH    ASC "Invalid pathname",00    ;$40
+EMMAXFILES       ASC "Maximum number of files open",00    ;$42
+EMINVALIDREF     ASC "Invalid reference number",00           ;$43
+EMDIRNOTFOUND    ASC "Directory not found",00 ;$44
+EMVOLNOTFOUND    ASC "Volume not found",00    ;$45
+EMNOENT          ASC "File not found",00  ;$46
+EMDUPFILENAME    ASC "Duplicate filename",00  ;$47
+EMVOLFULL        ASC "Volume full",00 ;$48
+EMVOLDIRFULL     ASC "Volume directory full",00   ;$49
+EMFILEFORMAT     ASC "Incompatible file format",00   ;$4a
+EMSTRGTYPE       ASC "Unsupported storage_type",00    ;$4b
+EMEOF            ASC "End of file encountered",00 ;$4c
+EMOUTOFRANGE     ASC "Position out of range",00   ;$4d
+EMFILELOCKED     ASC "File access error or file locked",00 ;$4e
+EMFILEISOPEN     ASC "File is open",00    ;$50
+EMDAMAGEDDIR     ASC "Directory structure damaged",00 ;$51
+EMNOTPRODOS      ASC "Not a ProDOS volume",00 ;$52
+EMBADPARAM       ASC "Invalid system call parameter",00   ;$53
+EMVCBTBLFULL     ASC "Volume Control Block table full",00     ;$55
+EMBADADDR        ASC "Bad buffer address",00  ;$56
+EMDUPVOL         ASC "Duplicate volume",00    ;$57
+EMDAMAGEDFILE    ASC "File structure damaged",00  ;$5a
+
+errorCodes
+    DB  ENOERR
+    DB  EBADCALLNUM
+    db  EBADPARMCNT
+    db  EINTRTBLFULL
+    db  EIO        
+    db  ENODEV    
+    db  EROFS    
+    db  EDISKSWITCHED
+    db  EINVALIDPATH
+    db  EMAXFILES  
+    db  EINVALIDREF
+    db  EDIRNOTFOUND
+    db  EVOLNOTFOUND
+    db  ENOENT     
+    db  EDUPFILENAME
+    db  EVOLFULL   
+    db  EVOLDIRFULL
+    db  EFILEFORMAT
+    db  ESTRGTYPE 
+    db  EEOF     
+    db  EOUTOFRANGE
+    db  EFILELOCKED
+    db  EFILEISOPEN
+    db  EDAMAGEDDIR
+    db  ENOTPRODOS
+    db  EBADPARAM
+    db  EVCBTBLFULL 
+    db  EBADADDR   
+    db  EDUPVOL   
+    db  EDAMAGEDFILE 
+errorCodeCount
+    db  errorCodeCount - errorCodes
+
+errorMessages
+    DA  EMNOERR
+    DA  EMBADCALLNUM
+    da  EMBADPARMCNT
+    da  EMINTRTBLFULL
+    da  EMIO        
+    da  EMNODEV    
+    da  EMROFS    
+    da  EMDISKSWITCHED
+    da  EMINVALIDPATH
+    da  EMMAXFILES  
+    da  EMINVALIDREF
+    da  EMDIRNOTFOUND
+    da  EMVOLNOTFOUND
+    da  EMNOENT     
+    da  EMDUPFILENAME
+    da  EMVOLFULL   
+    da  EMVOLDIRFULL
+    da  EMFILEFORMAT
+    da  EMSTRGTYPE 
+    da  EMEOF     
+    da  EMOUTOFRANGE
+    da  EMFILELOCKED
+    da  EMFILEISOPEN
+    da  EMDAMAGEDDIR
+    da  EMNOTPRODOS
+    da  EMBADPARAM
+    da  EMVCBTBLFULL 
+    da  EMBADADDR   
+    da  EMDUPVOL   
+    da  EMDAMAGEDFILE 
diff --git a/old/Makefile b/old/Makefile
new file mode 100644
index 0000000..d3d40a9
--- /dev/null
+++ b/old/Makefile
@@ -0,0 +1,52 @@
+# Builds copy command
+
+# Requirements:
+# 1. Gmake must be used.
+# 2. The cc65 compiler must be properly setup.
+
+ifndef CC65_TARGET
+	CC65_TARGET:=apple2enh
+endif
+
+CC=cl65
+CFLAGS=-O -t $(CC65_TARGET) -DTRACE
+LDFLAGS=-t $(CC65_TARGET)
+PGM=copy
+DISK_VOL=$(PGM)
+DISK=$(DISK_VOL).dsk
+AC=java -jar AppleCommander-ac-1.4.0.jar
+SYS_LOAD_ADDR=0x2000
+BIN_LOAD_ADDR=0x0803
+BASIC_AUX_TYPE=0x0801
+READ_TIME_LOAD_ADDR=0x0260
+MKDISK=$(AC) -pro140 $(DISK) $(DISK_VOL)
+OBJS=copy.o online.o prodos.o prodos-util.o
+SRCS=copy.c online.c prodos-util.c
+
+########################################
+
+all: $(DISK)
+
+$(DISK): $(PGM) 
+	$(RM) $(DISK)
+	$(AC) -pro140 $(DISK) $(DISK_VOL)
+	$(AC) -as $(DISK) $(PGM) BIN < $(PGM)
+
+$(PGM): $(OBJS)
+	$(CC) $(LDFLAGS) -o $@ $^
+
+copy.o: copy.c prodos.h
+	$(CC) -c $(CFLAGS) $<
+
+online.o: online.c prodos.h
+	$(CC) -c $(CFLAGS) $<
+
+prodos-util.o: prodos-util.c prodos.h
+	$(CC) -c $(CFLAGS) $<
+
+prodos.o: prodos.s prodos.h
+	ca65 -t $(CC65_TARGET) $<
+
+clean:
+	$(RM) $(OBJS) $(PGM) $(DISK)
+
diff --git a/old/copy-ca65.s b/old/copy-ca65.s
new file mode 100644
index 0000000..56a52f6
--- /dev/null
+++ b/old/copy-ca65.s
@@ -0,0 +1,114 @@
+********************************
+*                              *
+* COPY - COPIES FILES          *
+*                              *
+* AUTHOR:  BILL CHATFIELD      *
+* LICENSE: GPL2                *
+*                              *
+********************************
+
+********************************
+*                              *
+* CONSTANTS                    *
+*                              *
+********************************
+
+RDKEY          EQU   $FD0C      ;READS 1 CHAR
+CROUT          EQU   $FD8E      ;SUB TO OUTPUT CARRIAGE RETURN
+COUT           EQU   $FDED      ;SUB TO OUTPUT A CHARACTER
+PRBYTE         EQU   $FDDA      ;SUB TO PRINT ERROR MESSAGE
+BELL           EQU   $FF3A      ;SUBROUTINE TO BEEP
+PRODOS_MLI      =   $bf00           ;Address for MLI subroutine entry point
+SET_FILE_INFO   =   $c3             ;Code for system call
+GET_FILE_INFO   =   $c4             ;Code for system call
+ON_LINE         =   $c5             ;ID FOR ON_LINE MLI SYSTEM CALL
+
+
+********************************
+*                              *
+* puts                         *
+*                              *
+********************************
+
+.macro      puts    s
+            .local  nextchar
+            .local  finish
+            tya                 ;Preserve y
+            pha
+            ldy     #0          ;Prepare loop index
+nextchar:   lda     s,y         ;Load a character
+            cmp     #0          ;Check for end of string
+            beq     finish
+            jsr     cout
+            iny
+            jmp     nextchar
+finish:     pla                 ;Restore y
+            tay
+.endmacro
+
+.macro      movb    dest,src
+            lda     src
+            sta     dest
+.endmacro
+
+.macro      mova    dest,src
+            lda     src
+            sta     dest
+            lda     src+1
+            sta     dest+1
+.endmacro
+
+.proc       handleError
+            rts
+.endproc
+
+********************************
+*                              *
+* Main                         *
+*                              *
+********************************
+
+main:
+            movb    fileInfo+FileInfo::paramCount,$a
+            mova    fileInfo+FileInfo::pathName,srcFile
+
+            jsr     PRODOS_MLI      ;Call MLI subroutine
+            .byte   GET_FILE_INFO   ;Identify the system call
+            .addr   fileInfo        ;Address of system call args
+            beq     cont1           ;Returns 0 on success
+            jsr     handleError
+            rts
+
+
+; BSS is Block Started by Symbol for zero-initialized read/write data
+; Constructed by loader and zeroed out based on required size
+            .bss
+
+onlineVols: .res        256         ;SPACE FOR 16 DISK VOL RECORDS
+srcFile     .byte                   ;Length byte
+            .res        64          ;Characters of srcFile
+
+
+; DATA contains initialized read/write data - encoded into binary
+            .data
+
+onlineArgs: .byte       2           ;PARAMETER COUNT
+            .byte       0           ;UNIT NUMBER, 0=ALL
+            .addr       _onlineVols ;ADDRESS OF OUTPUT BUFFER
+
+.struct     FileInfo
+            paramCount  .byte
+            pathName    .addr
+            access      .byte
+            fileType    .byte
+            auxType     .word
+            storageType .byte
+            blocksUsed  .word
+            modDate     .word
+            modTime     .word
+            createDate  .word
+            createTime  .word
+.endstruct
+
+fileInfo:   .tag        FileInfo
+
diff --git a/old/copy.c b/old/copy.c
new file mode 100644
index 0000000..d0d4ecf
--- /dev/null
+++ b/old/copy.c
@@ -0,0 +1,63 @@
+#include <stdio.h>  /* FILENAME_MAX */
+#include <string.h> /* strerror */
+#include <errno.h>  /* errno */
+#include "prodos.h" /* prodosGetFileInfo, prodosSetFileInfo */
+
+void copy(const char *srcName, const char *dstName);
+
+#define BUFFER_SIZE 2048
+
+char src[FILENAME_MAX];
+char dst[FILENAME_MAX];
+char buf[BUFFER_SIZE];
+
+struct ProdosFileInfo fileAttributes;
+struct ProdosPathName srcPathName;
+struct ProdosPathName dstPathName;
+
+void main(void)
+{
+    printf("Source file:");
+    fgets(src, FILENAME_MAX, stdin);
+    printf("Destination file:");
+    fgets(dst, FILENAME_MAX, stdin);
+
+    copy(src, dst);
+}
+
+void copy(const char *srcName, const char *dstName)
+{
+    FILE *src, *dst;
+    size_t readCount;
+    int errorCode;
+
+    fileAttributes.paramCount = PRODOS_GET_FILE_INFO_PARAM_COUNT;
+    fileAttributes.pathName = prodosAssignPathName(&srcPathName, srcName);
+    errorCode = prodosGetFileInfo(&fileAttributes);
+    if (errorCode > 0) {
+        fprintf(stderr, "%s: %s\n", srcName, prodosGetMessage(errorCode));
+        return;
+    }
+    
+    src = fopen(srcName, "r");
+    dst = fopen(dstName, "w");
+
+    while ((readCount = fread(buf,1,BUFFER_SIZE,src)) == BUFFER_SIZE) {
+        fwrite(buf,1,BUFFER_SIZE,dst);
+    }
+    if (feof(src) && readCount > 0) {
+        fwrite(buf,1,readCount,dst);
+    } else if (ferror(src)) {
+        fprintf(stderr, "%s: %s\n", srcName, strerror(errno));
+    }
+    fclose(dst);
+    fclose(src);
+
+    fileAttributes.paramCount = PRODOS_SET_FILE_INFO_PARAM_COUNT;
+    fileAttributes.pathName = prodosAssignPathName(&dstPathName, dstName);
+    errorCode = prodosSetFileInfo(&fileAttributes);
+    if (errorCode > 0) {
+        fprintf(stderr, "%s: %s\n", dstName, prodosGetMessage(errorCode));
+        return;
+    }
+}
diff --git a/old/online-mli.s b/old/online-mli.s
new file mode 100644
index 0000000..80b154f
--- /dev/null
+++ b/old/online-mli.s
@@ -0,0 +1,32 @@
+        .export _onlineSysCall
+        .export _onlineVols
+
+ON_LINE     =   $c5     ;ID FOR ON_LINE MLI SYSTEM CALL
+PRODOS_MLI  =   $bf00   ;ADDRESS OF MLI ENTRY POINT
+
+.proc       _onlineSysCall
+
+            jsr         PRODOS_MLI  ;CALL MACHINE LANGUAGE INTERFACE
+            .byte       ON_LINE     ;SPECIFY THE ON_LINE SYSTEM CALL
+            .addr       onlineArgs  ;SPECIFY ADDRESS OF ARGUMENTS
+
+;           sta         retCode     ;Store the return code
+;            lda         #<retCode   ;PUT LOW BYTE INTO ACCUMULATOR
+;            ldx         #>retCode   ;PUT HIGH BYTE INTO X
+            rts
+.endproc
+
+; BSS is Block Started by Symbol for zero-initialized read/write data
+; Constructed by loader and zeroed out based on required size
+            .bss
+
+retCode:    .byte       0
+_onlineVols:.res        256         ;SPACE FOR 16 DISK VOL RECORDS
+
+; DATA contains initialized read/write data - encoded into binary
+            .data
+
+onlineArgs: .byte       2           ;PARAMETER COUNT
+            .byte       0           ;UNIT NUMBER, 0=ALL
+            .addr       _onlineVols ;ADDRESS OF OUTPUT BUFFER
+
diff --git a/old/online-old.c b/old/online-old.c
new file mode 100644
index 0000000..71741bf
--- /dev/null
+++ b/old/online-old.c
@@ -0,0 +1,33 @@
+#include <stdint.h>
+
+#define PRODOS_MLI 0xbf00
+#define ON_LINE_SYSTEM_CALL 0xc5
+#define PRODOS_FILE_NAME_MAX_LEN 15
+typedef char ProdosFileName[PRODOS_FILE_NAME_MAX_LEN + 1];
+typedef ProdosFileName ProdosFileNameArray16[16];
+typedef struct OnlineSystemCallArguments {
+    uint8_t argumentCount;
+    uint8_t unitNumber;
+    ProdosFileNameArray16 *volumesOutputBuffer;
+} OnlineSystemCallArguments;
+
+static ProdosFileNameArray16 volumes;
+static OnlineSystemCallArguments arguments;
+
+ProdosFileNameArray16 *online(uint8_t *errorCode)
+{
+    arguments.argumentCount = 2;
+    arguments.unitNumber = 0; // All units
+    arguments.volumesOutputBuffer = &volumes;
+    
+    __asm__("jsr %w", PRODOS_MLI);
+    __asm__("db  %b", ON_LINE_SYSTEM_CALL);
+    __asm__("da  %v", &arguments);
+    __asm__("bne %g", errorHandler);
+
+    return &volumes;
+
+errorHandler:
+    return errorCode;
+}
+
diff --git a/old/online.c b/old/online.c
new file mode 100644
index 0000000..a48dde3
--- /dev/null
+++ b/old/online.c
@@ -0,0 +1,69 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+#include <device.h>
+#include "prodos.h"
+
+extern uint8_t onlineVols[];
+extern uint8_t onlineSysCall();
+
+enum ProdosErrorCode online(struct ProdosVolumes *vols)
+{
+    uint8_t byte;
+    uint8_t i;
+    uint8_t nameLength;
+    enum ProdosErrorCode errorCode;
+    struct ProdosVolume *volume;
+
+    errorCode = onlineSysCall();
+    if (errorCode != PRODOS_ERR_NO_ERROR) {
+        return NULL;
+    }
+
+    for (i = 0; i < PRODOS_MAX_VOLUME_COUNT; ++i) {
+        byte = onlineVols[i*16];
+        if (byte == 0) {
+            vols->count = i;
+            break;
+        }
+        volume = &(vols->volumes[i]);
+        volume->drive = ((byte & 0x80) >> 7) + 1;
+        volume->slot = (byte & 0x70) >> 4;  
+        nameLength = byte & 0x0f;
+        strncpy(volume->name, &(onlineVols[i*16+1]), nameLength);
+        volume->name[nameLength] = '\0';
+    }
+    return errorCode;
+}
+
+struct ProdosVolume volume;
+struct ProdosVolumes volumes;
+enum ProdosErrorCode errorCode;
+
+void printOnline(void)
+{
+    uint8_t i, dev;
+    char volName[FILENAME_MAX];
+    
+    errorCode = online(&volumes);
+    if (errorCode > 0) {
+        printf("Error: %d\n", errorCode);
+        exit(1);
+    }
+
+    for (i = 0; i < volumes.count; ++i) {
+        volume = volumes.volumes[i];
+        if (strlen(volume.name)>0) {
+            printf("S%d,D%d /%s\n", volume.slot, volume.drive, volume.name);
+        }
+    }
+
+    dev = getfirstdevice();
+    while (dev != INVALID_DEVICE) {
+        getdevicedir(dev, volName, sizeof(volName));
+        printf("device=%d volume=%s\n", dev, volName);
+        dev = getnextdevice(dev);
+    }
+}
+
diff --git a/old/prodos-util.c b/old/prodos-util.c
new file mode 100644
index 0000000..c04881e
--- /dev/null
+++ b/old/prodos-util.c
@@ -0,0 +1,42 @@
+#include <string.h> /* size_t */
+#include "prodos.h"
+
+struct ProdosPathName *
+prodosAssignPathName(struct ProdosPathName *dest, const char *src)
+{
+    size_t i;
+    char c;
+    char *name;
+
+    name = dest->name;
+    for (i = 0; i < PRODOS_MAX_PATHNAME_LENGTH && (c = src[i]) != '\0'; ++i) {
+        name[i] = c;
+    }
+    dest->length = i;
+    return dest;
+}
+
+char *
+prodosGetMessage(enum ProdosErrorCode code)
+{
+    char *message;
+
+    switch (code) {
+        case PRODOS_ERR_NO_ERROR:
+            message = "No error";
+            break;
+        case PRODOS_ERR_BAD_SYS_CALL_NUM:
+            message = "Bad system call number";
+            break;
+        case PRODOS_ERR_BAD_PARAM_COUNT:
+            message = "Bad parameter count";
+            break;
+        case PRODOS_ERR_INTR_VECT_TBL_FULL:
+            message = "Interrupt vector table full";
+            break;
+        default:
+            message = "Unknown error";
+    }
+    return message;
+}
+
diff --git a/old/prodos.h b/old/prodos.h
new file mode 100644
index 0000000..f84a4f4
--- /dev/null
+++ b/old/prodos.h
@@ -0,0 +1,66 @@
+#ifndef PRODOS
+#define PRODOS
+
+#include <stdint.h> /* uint8_t, uint16_t */
+
+#define PRODOS_GET_FILE_INFO_PARAM_COUNT 0x0a
+#define PRODOS_SET_FILE_INFO_PARAM_COUNT 0x07
+#define PRODOS_MAX_PATHNAME_LENGTH 64
+
+#define PRODOS_MAX_VOLUME_NAME_LEN 15
+#define PRODOS_MAX_VOLUME_COUNT 16
+
+enum ProdosErrorCode {
+    PRODOS_ERR_NO_ERROR = 0,
+    PRODOS_ERR_BAD_SYS_CALL_NUM = 1,
+    PRODOS_ERR_BAD_PARAM_COUNT = 4,
+    PRODOS_ERR_INTR_VECT_TBL_FULL = 25,
+};
+
+struct ProdosVolume {
+    uint8_t drive;
+    uint8_t slot;
+    uint8_t nameLength;
+    char name[PRODOS_MAX_VOLUME_NAME_LEN+1];
+};
+
+struct ProdosVolumes {
+    uint8_t count;
+    struct ProdosVolume volumes[PRODOS_MAX_VOLUME_COUNT];
+};
+
+struct ProdosPathName 
+{
+    uint8_t length;
+    char name[PRODOS_MAX_PATHNAME_LENGTH];
+};
+
+struct ProdosFileInfo
+{
+    uint8_t paramCount;
+    struct ProdosPathName *pathName;
+    uint8_t access;
+    uint8_t fileType;
+    uint16_t auxType;
+    uint8_t storageType;
+    uint16_t blocksUsed;
+    uint16_t modDate;
+    uint16_t modTime;
+    uint16_t createDate;
+    uint16_t createTime;
+};
+
+extern int __fastcall__
+prodosGetFileInfo(struct ProdosFileInfo *fileInfo);
+
+extern int __fastcall__
+prodosSetFileInfo(struct ProdosFileInfo *fileInfo);
+
+extern struct ProdosPathName *
+prodosAssignPathName(struct ProdosPathName *dest, const char *src);
+
+extern char *
+prodosGetMessage(enum ProdosErrorCode code);
+
+#endif
+
diff --git a/old/prodos.s b/old/prodos.s
new file mode 100644
index 0000000..25983a7
--- /dev/null
+++ b/old/prodos.s
@@ -0,0 +1,57 @@
+        .export _prodosGetFileInfo
+        .export _prodosSetFileInfo
+        .export _onlineSysCall
+        .export _onlineVols
+
+
+PRODOS_MLI      =   $bf00           ;Address for MLI subroutine entry point
+SET_FILE_INFO   =   $c3             ;Code for system call
+GET_FILE_INFO   =   $c4             ;Code for system call
+ON_LINE         =   $c5             ;ID FOR ON_LINE MLI SYSTEM CALL
+
+.proc       _prodosGetFileInfo
+            sta     fileInfo        ;Store low-byte of C address param
+            stx     fileInfo+1      ;Store high-byte of C address param
+            jsr     PRODOS_MLI      ;Call MLI subroutine
+            .byte   GET_FILE_INFO   ;Identify the system call
+fileInfo:   .addr   $0000           ;Address of system call args
+            ldx     #0              ;Zero high byte of int return value
+            rts                     ;Accum has error code, low byte of int
+.endproc
+
+.proc       _prodosSetFileInfo
+            sta     fileInfo        ;Store low-byte of C address param
+            stx     fileInfo+1      ;Store high-byte of C address param
+            jsr     PRODOS_MLI      ;Call MLI subroutine
+            .byte   SET_FILE_INFO   ;Identify the system call
+fileInfo:   .addr   $0000           ;Address of system call args
+            ldx     #0              ;Zero high byte of int return value
+            rts                     ;Accumulator has error code
+.endproc
+
+.proc       _onlineSysCall
+
+            jsr         PRODOS_MLI  ;CALL MACHINE LANGUAGE INTERFACE
+            .byte       ON_LINE     ;SPECIFY THE ON_LINE SYSTEM CALL
+            .addr       onlineArgs  ;SPECIFY ADDRESS OF ARGUMENTS
+
+;           sta         retCode     ;Store the return code
+;            lda         #<retCode   ;PUT LOW BYTE INTO ACCUMULATOR
+;            ldx         #>retCode   ;PUT HIGH BYTE INTO X
+            rts
+.endproc
+
+; BSS is Block Started by Symbol for zero-initialized read/write data
+; Constructed by loader and zeroed out based on required size
+            .bss
+
+retCode:    .byte       0
+_onlineVols:.res        256         ;SPACE FOR 16 DISK VOL RECORDS
+
+; DATA contains initialized read/write data - encoded into binary
+            .data
+
+onlineArgs: .byte       2           ;PARAMETER COUNT
+            .byte       0           ;UNIT NUMBER, 0=ALL
+            .addr       _onlineVols ;ADDRESS OF OUTPUT BUFFER
+
diff --git a/old/prodos.s.bak b/old/prodos.s.bak
new file mode 100644
index 0000000..24d3abe
--- /dev/null
+++ b/old/prodos.s.bak
@@ -0,0 +1,36 @@
+        .export _mliGetFileInfo
+        .export _mliSetFileInfo
+
+SET_FILE_INFO   =   $c3             ;Code for system call
+GET_FILE_INFO   =   $c4             ;Code for system call
+PRODOS_MLI      =   $bf00           ;Address for MLI subroutine entry point
+
+.proc       _mliGetFileInfo
+            sta     fileInfo        ;Store low-byte of C address param
+            stx     fileInfo+1      ;Store high-byte of C address param
+            jsr     PRODOS_MLI      ;Call MLI subroutine
+            .byte   GET_FILE_INFO   ;Identify the system call
+fileInfo:   .addr   $0000           ;Address of system call args
+            ldx     #0              ;Zero high byte of int return value
+            rts                     ;Accum has error code, low byte of int
+.endproc
+
+.proc       _mliSetFileInfo
+            sta     fileInfo        ;Store low-byte of C address param
+            stx     fileInfo+1      ;Store high-byte of C address param
+            jsr     PRODOS_MLI      ;Call MLI subroutine
+            .byte   SET_FILE_INFO   ;Identify the system call
+fileInfo:   .addr   $0000           ;Address of system call args
+            ldx     #0              ;Zero high byte of int return value
+            rts                     ;Accumulator has error code
+.endproc
+
+; BSS is Block Started by Symbol for zero-initialized read/write data
+; Constructed by loader and zeroed out based on required size
+
+            .bss
+
+; DATA segment contains initialized read/write data - encoded into binary
+
+            .data
+
diff --git a/online.c b/online.c
index 71741bf..0e556f3 100644
--- a/online.c
+++ b/online.c
@@ -1,33 +1,55 @@
+#include <stdio.h>
 #include <stdint.h>
 
 #define PRODOS_MLI 0xbf00
-#define ON_LINE_SYSTEM_CALL 0xc5
-#define PRODOS_FILE_NAME_MAX_LEN 15
-typedef char ProdosFileName[PRODOS_FILE_NAME_MAX_LEN + 1];
-typedef ProdosFileName ProdosFileNameArray16[16];
-typedef struct OnlineSystemCallArguments {
+#define ON_LINE (uint8_t) 0xc5
+#define PRODOS_NAME_CAPACITY 16
+
+struct OnlineArguments {
     uint8_t argumentCount;
     uint8_t unitNumber;
-    ProdosFileNameArray16 *volumesOutputBuffer;
-} OnlineSystemCallArguments;
+    char **volumes;
+};
 
-static ProdosFileNameArray16 volumes;
-static OnlineSystemCallArguments arguments;
+struct OnlineArguments arguments;
+char volumes[16][PRODOS_NAME_CAPACITY];
+uint8_t argumentsAddrLowByte;
+uint8_t argumentsAddrHighByte;
 
-ProdosFileNameArray16 *online(uint8_t *errorCode)
+void online(void)
 {
     arguments.argumentCount = 2;
     arguments.unitNumber = 0; // All units
-    arguments.volumesOutputBuffer = &volumes;
+    arguments.volumes = volumes;
+
+    __asm__("lda #%b", ON_LINE);
+    __asm__("sta %g", l1);
+    
+    argumentsAddrLowByte = (uint8_t) &arguments;
+    argumentsAddrLowByte = (uint8_t) &arguments >> 4;
+
+    __asm__("lda %v", argumentsAddrLowByte);
+    __asm__("sta %g", l2);
+
+    __asm__("lda %v", argumentsAddrHighByte);
+    __asm__("sta %g", l3);
     
     __asm__("jsr %w", PRODOS_MLI);
-    __asm__("db  %b", ON_LINE_SYSTEM_CALL);
-    __asm__("da  %v", &arguments);
+l1:
+    __asm__("nop");
+l2:
+    __asm__("nop");
+l3:
+    __asm__("nop");
     __asm__("bne %g", errorHandler);
 
-    return &volumes;
-
 errorHandler:
-    return errorCode;
+    fprintf(stderr, "Online system call failed\n");
+}
+
+void main(void)
+{
+    online();
+    puts(volumes[0]);
 }
 
diff --git a/online.s b/online.s
deleted file mode 100644
index 331cc6e..0000000
--- a/online.s
+++ /dev/null
@@ -1,26 +0,0 @@
-        .export _onLineSysCall
-        .export _onLineVols
-
-ON_LINE     =   $c5     ;ID FOR ON_LINE MLI SYSTEM CALL
-PRODOS_MLI  =   $bf00   ;ADDRESS OF MLI ENTRY POINT
-
-.proc       _onLineSysCall
-
-            jsr         PRODOS_MLI  ;CALL MACHINE LANGUAGE INTERFACE
-            .byte       ON_LINE     ;SPECIFY THE ON_LINE SYSTEM CALL
-            .addr       onlineArgs  ;SPECIFY ADDRESS OF ARGUMENTS
-
-            sta         retCode     ;Store the return code
-            lda         #<retCode   ;PUT LOW BYTE INTO ACCUMULATOR
-            ldx         #>retCode   ;PUT HIGH BYTE INTO X
-            rts
-.endproc
-
-.bss
-retCode:    .byte       0
-_onLineVols:.res        256         ;SPACE FOR 16 DISK VOL RECORDS
-
-onlineArgs: .byte       2           ;PARAMETER COUNT
-            .byte       0           ;UNIT NUMBER, 0=ALL
-            .addr       _onLineVols ;ADDRESS OF OUTPUT BUFFER
-
diff --git a/onlinesys.s b/onlinesys.s
new file mode 100644
index 0000000..a19d3e1
--- /dev/null
+++ b/onlinesys.s
@@ -0,0 +1,21 @@
+        .export         _online
+        .export         _olerr
+    
+        .include        "mli.inc"
+
+        .bss
+
+_olerr: .byte   $00
+
+        .code
+
+_open:
+        lda     #ON_LINE_CALL
+        ldx     #ON_LINE_COUNT
+        jsr     callmli
+        bcc     done
+
+        sta     _olerr
+
+done:
+        rts