*** VDT Version 2.7 (Release: December 30, 1997)

1. New support 
   Of VHDL'93 specification.

2. Put ST_generate into Symbols group,
   With many new fields for declarations.

3. Added field `name' for statement-label 
   To almost statements,
   Except ST_cond_wave, ST_sel_wave, ST_waveform, ST_if_alt, ST_case_alt

4. Added field `time_expr' 
   For delay-mechanism,
   To ST_cond_sig_assign, ST_sel_sig_assign, ST_sig_assign.

5. Support waveform UNAFFECTED,
   Represented by ST_waveform 
   (_value_expr = NULL, _time_expr = NULL).

6. Support POSTPONED process,
   Represented by setting field `flag' 
   To non-zero.

7. Support IMPURE function,
   Represented by setting field `flag' 
   To non-zero.


*** VDT Version 2.6 (Release: December 1, 1996)

1. Renamed field `raw_value' of O_literal
   To `string'.

2. Renamed field `bit_string_value' of L_bit_string
   To `string_value'.

3. Renamed field `int_value' of L_integer
   To `abstract_value'.

4. Renamed field `float' of L_float
   To `abstract_value'.

5. Renamed field `initial_expr' of O_constant,
   O_signal, O_variable, and O_file to `expression'.

6. Added O_comment as one of Basic object.


*** VDT Version 2.5 (Release: January 31, 1996)

1. Renamed source files,
   From: interface.h interface.cc
   To basicMan.h basicMan.cpp

2. Renamed source files,
   From: objman.h objman.cc
   To: basicSup.h basicSup.cpp

3. Renamed source files,
   From: desman.h desman.cc
   To: designMan.h designMan.cpp

4. Renamed source files,
   From: libman.h libman.cc
   To: libraryMan.h libraryMan.cpp

5. Renamed Design object for package-body,
   From (package-identifier + "__" )
   To (package-identifier + "__" + package-identifier)

6. Removed O_ext_ref
   Which was used for external-reference.

7. Removed L_character,
   Which was used for character-literal.

8. Removed field `symbols' 
   From O_context.

9. Removed routine `search' 
   From O_library.

10. Added field `ext_ref' to O_use
    With removing fields `library/design_unit/suffix'.

11. Added routine `search' 
    To O_use.

12. Removed field `ext_refs' from O_context, O_use,
    O_arch_body, O_pack_body, and O_configuration.

13. Added field `function' to arithmetical-operator,
    Which points to O_subprogram 
    After overloading-resolution.

14. Create implicitly-declared-subprograms
    For file-type and access-type 
    While analyzing.

15. Support extended-graphic-character 
    For Hangul comment.

16. Provided
    VHDL static-semantic-checker.


*** VDT Version 2.0 (Release: December 30, 1994)

1. Defined Basic object in files,
   interface.h interface.cc
   objman.h objman.cc

2. Defined Design object in files,
   desman.h desman.cc

3. Defined Lib object in files,
   libman.h libman.cc

4. Provided VDT utilities,
   VHDL-Code analyzer
   VHDL-Code generator
   Design-Library browser
   VIF (VHDL Intermediate Form) dumper.

