NAME

       z80dasm - Z80 assembly generating disassembler

SYNOPSIS

       z80dasm [ options ] file

DESCRIPTION

       z80dasm  disassembles a binary file containing Z80 machine code into Z80 assembly language
       source (including a number of undocumented opcodes). It can  try  to  guess  locations  of
       labels in the code or the labels can be specified by hand in the form of a symbol file. If
       given proper information the disassembler can also split the binary  file  into  code  and
       data sections of several different types.

       Generated source file can be assembled back into the original binary using z80asm, zasm or
       the original Zilog assembler (when the --zilog option was used).

OPTIONS

       -a, --address
              Print the address of the memory location corresponding to  each  line  of  assembly
              code in a comment at the end of the line.

       -b, --block-def=FILE
              Read  block information from a file. If this option is not specified the default is
              for the entire file to contain machine code. See BLOCK FILE below.

       -g, --origin=ORG
              Specify the start address of the binary code being  disassembled.  A  corresponding
              org directive is generated in the output file.  The argument is read in hexadecimal
              if  it  begins with 0x or 0X, in octal  if  it  begins  with  0,  and  in  base  10
              otherwise. Default is 0x0100.

       -h, --help
              Show summary of options and exit.

       -l, --labels
              Try  to  guess  label locations from jump instructions and add them to the assembly
              code.

       -o, --output=FILE
              Specify the output file. Default is to write to standard output.

       -s, --sym-output=FILE
              Write symbol information into a file.

       -S, --sym-input=FILE
              Read symbol information from a file. See SYMBOL FILE below.

       -t, --source
              Print the binary data corresponding to each line of assembly code in a  comment  at
              the  end  of  the  line.  Data  is  printed  in  hex  and ASCII. This is useful for
              identifying data sections in the first disassembly.

       -u, --undoc
              By default, all undocumented instructions are disassembled as defb directives  with
              the instruction name in a comment. This is due to missing or buggy support for many
              of these  instructions  in  z80asm.  If  this  option  is  specified,  undocumented
              instructions are written directly into the disassembly.

       -v, --verbose
              Increase verbosity level.  Specify multiple times to be more verbose.  Messages are
              sent to standard error.

       -V, --version
              Display version information and exit.

       -z, --zilog
              Enable compatibility mode for the original Zilog Z80 assembler. This currently only
              changes the syntax of relative jumps.

SYMBOL FILE

       Symbol files written by z80dasm can be directly used as input symbol files with the --sym-
       input option. The following directives are  recognized  in  input  symbol  files  and  are
       propagated to the output symbol files:

       include "filename"
              Include another symbol file. Double quotes are mandatory. Included files must be in
              the current directory.

       symbol: equ value
              Define a symbol with a value. The value is read in hexadecimal if it begins with 0x
              or 0X, in octal if it begins with 0, and in base 10 otherwise. Default is 0x0100.

       ; comment
              All characters between a semi-colon and end of line are ignored.

BLOCK FILE

       Block  files  specify the boundaries between different blocks (sections) of binary data in
       the disassembler input file. The following directives are recognized:

       name: [ unlabeled ] [ start | first ] address [ unlabeled ] [ end | last  ]  address  type
       type
              Define  a  block  with  the  start  and end address that contains a certain type of
              binary data.

              Start address is the 16 bit address of  the  first  byte  in  the  block.  Keywords
              "start"  and  "first" are synonymous. If the keyword "end" is used, the end address
              is the 16 bit address of the last byte in the block plus one. If the keyword "last"
              is used, the end address is the 16 bit address of the last byte in block.

              Normally  labels  are  defined  at the addresses specified in the block definition.
              This can be suppressed by adding the keyword "unlabeled" before the address.

       ; comment
              All characters between a semi-colon and end of line are ignored.

       The following block types are supported:

       code   Block containing Z80 machine code. Data in  this  block  will  be  written  in  Z80
              assembly language.

       bytedata
              Data  block containing separate bytes. Data in this block will be written with defb
              directives.

       worddata
              Data block containing 16 bit words (low order byte first). Data in this block  will
              be written with defw directives.

       pointers
              Data  block  containing  16  bit  pointers  (low  order  byte  first). This type is
              equivalent to worddata except that values will be replaced with labels  where  that
              is possible.

DIAGNOSTICS

       If  disassembly was successful z80dasm returns 0. On error diagnostic messages are printed
       to standard error and z80dasm returns 1.

BUGS

       Please report bugs to tomaz.solc@tablix.org

AUTHOR

       z80dasm is based largely on dz80 , written by Jan Panteltje. Feature enhancements and  bug
       fixes were made by Tomaz Solc.

SEE ALSO

       z80asm(1)