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D52 8052 Disassembler (includes D48 and DZ80)

Licence: GNU General Public License version 3 (see the file COPYING).
 NOTE: As Novell and Microsoft are in violation of the GPL, this software
 may not be distributed by either Novell or Microsoft. The same prohibition
 applies to any company that enters into an agreement with Microsoft regarding
 Microsoft's phony patent claims against Linux. In addition, no one who cannot
 honor ALL the requirements of GPL version 3 may distribute this software.

Maintainership Note:

D52 appears to be unmaintained.  Neither of the locations named in the original
README still exist ( or

A mirror of the D52 homepage is at

I checked in the available there into GitHub and applied the
following patches:

  - Fix format security issue:
  - Don't strip binaries:
  - Fix N directive bug:
  - Fix T directive bug:

Time permitting, I will be making additional bug fixes and adding features that
I personally want.  I welcome pull requests from others.

New Features:
Version 3.3 now includes a code analysis option for the 8052 disassembler.
The -t command line option causes D52 to trace and analyze the code in the
file to be disassembled to determine which parts of the file are actually
executable code, and which parts are data, such as ascii text, 8-bit binary
data, 16-bit binary data or pointers.

The results of the analysis are written to a control file which is then used in
the disassembly process. Use of the -t option will overwrite any existing
control file for the program to be disassembled, and so should only be used on
the first disassembly. You may modify the control file with any text editor to
correct any analysis errors or to add new directives for subsequent
disassemblies of a file.

The code analysis option is available only in D52 and DZ80. This feature should
be considered beta test, although D52 as a whole is a mature program.


Version 3.4.1
  Changed license to GNU General Public License Version 3.
  Improved code analysis routines.
  If code analysis (-t option) fails, outputs a warning message instead of an
   error message. Increased size of trace stacks for code analysis.
  Changed date/time output to year/month/day format.
  Added address offset directive ('o' control file directive that has the same
   effect as the x command line option.
  Fixed errors in 8048 cycle table.
  Applied Frieder Ferlemann's patch to allow hexadecimal values in the control
   file to optionally be prefixed with "0x" (ie: either 1234 or 0x1234).
  Fixed bug that would cause all data from an Intel hex record to be lost if
   the addresses for the block included 0ffffh.

Version 3.4.0
  Added cycle count directive('z' control file directive) and command line
   option to read cycle count file for d52 derivatives. Many thanks to Jan
   Waclawek for suggesting this feature and for implementing the code. Please
   read Jan's documetation in the 'cyclefiles' directory.
  Bug fixes for the 8048 disassembler.
  Improvements in output formatting.
  Improved control file error messages.
  Fixed bug that caused quoted operand symbols (ie: ' ') with non-visible
   characters to be truncated.
  Added Y directive. This is the same as the X directive except that an EQU
   statement will not be generated for the operand name.
  Added N directive to suppress automatic generation of a label for addresses
   referenced that are really constants instead of addresses.
  Added N command line option to output operands in C style (0xcd instead of 0cdh).
  Added P command line option to output pseudo ops with a leading dot (eg: .equ).

Version 3.3.9
  Adds dz80 flags -80 and -85 for disasembling with 8080 or 8085 mnemonics.

Version 3.3.8
  Fixes compile errors on Mac OSX and BSD unixes. Also fixed error in Z80
   analysis trace routine. Thanks to Brian Foley for spotting these problems.

Version 3.3.7
  Adds the 'n' directive to suppress automatic generation of a label for a
   referenced address.

Version 3.3.6
  Now allows you to specify the file extension of the file to be disassembled
   (eg: d52 -d testfile.hex). If you specify the extention, the -b (binary),
   -h (Intel hex), and -c (CP/M .com file if using DZ80) flags are not required.
  Fixed bug that caused assembler pseudo opcodes to not be output in upper
   case if the -u option was given on the command line, but no control file
   existed for the file to be disassembled.
  Suppress generation of an equ statement for an address if a label for
   that address had already been output. (This bug would cause some cross-
  assemblers to output an error even though the value of the equ matched
   the address of the label.)
  The keil A51 option (-k) should be used only if you intend to re-assemble
   the output file using the older DOS version of A51.

Version 3.3.5
  Fixes bug with patch directive. Code cleanup and minor bug fixes.
  Will no longer abort if input file exceeds 64KB, but code beyond 64K will be

Version 3.3.4
  Adds a new command line option and a new control file directive.
  The -u option causes mnemonics, labels, symbols, etc to be output in upper
   case for cross assemblers that may require upper case code. Strings,
   literal data, and comments are not affected. The P directive is similar to
   the header comment directive (#) except that the user string will be output
   as code, rather than as a comment. May be useful for inserting include
   statements or macro definitions into the output file. A preliminary trace
   option has been added to the Z80 disassembler (DZ80), but is still
   experimental--use it with caution. V3.3.4 also includes some bug fixes.

Version 3.3.3
  Corrects a bug that would allow more than one equate statement to be
   generated for name symbols with the same value. Inline comments now allowed
   for byte (8-bit) data. Corrected endian problem with Z80 disassembler.
  Changed format of 'd' directive.

Version 3.3.2
  Allows inline comments after address and word data.
  Corrects a bug that would force word data following a header comment to be
   interpreted as byte data.

Version 3.3.1
  D52 corrects a bug regarding the Keil flag.

Version 3.3
  DZ80 now has a command line option (-c) to disassemble CP/M .com files, in
   addition to hex and binary files.

The Future:

Dis52, a GUI front end for D52, D48 and DZ80, is currently under development,
and a preview version for Linux (or other Unix-like OS) is now available. (Due
to flaws in the design of Windows, Dis52 is not available for Windows.)

Dis52 requires the SDL (Simple DirectMedia Layer) library. SDL can be downloaded

Jeff Post
j_post <AT> pacbell <DOT> net
September, 2007

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