README.DOC File
Release Notes for the Microsoft(R) Macro Assembler
Professional Development System, Version 6.0
(C) Copyright Microsoft Corporation, 1991
This document contains release notes for version 6.0 of the
Microsoft Macro Assembler Professional Development System for
MS-DOS(R) and the Microsoft Operating System/2 (MS(R) OS/2). The
information in this document and in the Microsoft Advisor (online
help) is more up-to-date than that in the manuals.
Microsoft improves its languages documentation at the time of
reprinting, so some of the information in this file may already be
included in your manuals.
================================< Contents >================================
This file has 7 parts:
Part Contents
---- --------
1 Information for MASM 5.1 programmers
2 Notes on "Installing and Using"
3 Notes on "MASM 6.0 Reference"
4 Notes on "MASM 6.0 Programmer's Guide"
5 Using the DOS-Extended assembler
6 Changes to CMACROS.INC
7 Known assembler bugs
===============< Part 1: Information for MASM 5.1 programmers >=============
"Quick Start" booklet
---------------------
If you have programs that assemble with previous versions of MASM,
this booklet will help you to use MASM 6.0.
=================< Part 2: Notes on "Installing and Using" >================
Installation Program Notes
--------------------------
- Use "SETUP /M" if you are using a monochrome display adapter
as your primary display.
- Under OS/2, if you are already running QuickHelp as a keyboard
monitor, disable it before running SETUP so that it can copy
new versions of QuickHelp and MSHELP.DLL to your hard disk.
==================< Part 3: Notes on "MASM 6.0 Reference" >=================
Page Note
---- ----
16 MASM /D Option
--------------
The /D Option is translated as follows:
/D Creates a Pass 1 listing. Translated to /Fl /Sf.
17 ML /VM Option
-------------
/VM Enables virtual memory under MS-DOS.
33 EXITM Directive
---------------
The EXITM directive takes an optional textitem, not an
expression.
152 XCHG Instruction
----------------
The second example line should be as follows:
xchg dl, dh
==============< Part 4: Notes on "MASM 6.0 Programmer's Guide" >============
Reserved Words
--------------
Add this paragraph to the description of reserved words in Section
1.21, "Reserved Words," and Appendix D, "MASM Reserved Words":
With the /Zm command-line option or OPTION M510, keywords and
instructions that are not available in the current CPU mode (such as
ENTER under .8086) are not treated as keywords. The USE32, FLAT, FAR32,
and NEAR32 segment types and the 80386/486 registers are not keywords
with processor selection directives less than .386.
ALIGN, EVEN, and ORG in Structures and Unions
---------------------------------------------
Add this paragraph to Section 5.2, "Structures and Unions."
The ALIGN, EVEN, and ORG directives can be used during structure
definition to modify how offsets of elements are defined. The EVEN
and ALIGN directives will round the current field offset up to the
specified align value by inserting padding bytes into the skipped
space. The ORG directive may be used to change the current field
offset to a new value, either positive or negative. If the ORG
directive is used in a structure definition, you cannot create an
instance of the structure.
Nested Structure Example
------------------------
Change this line in the first example of Section 5.2.2, "Defining
Structure and Union Variables."
ITYPE UNION
should be:
UNION ITYPE
PUSHCONTEXT/POPCONTEXT Table
----------------------------
The table in Section 9.7.2, "Testing for Argument Type and
Environment" should be as follows:
Option Description
------ -----------
ASSUMES Saves segment register information
LISTING Saves listing and CREF information
CPU Saves current CPU and processor
RADIX Saves current default radix
ALL All of the above
New Anonymous Bitfield Syntax
-----------------------------
Add these paragraphs to Section 16.3.5, "Bit Fields."
H2INC translates anonymous bitfields by padding with a tag
corresponding to the bit position.
For example,
struct s
{
int :8;
int j:8;
}
becomes:
s RECORD j@s:8,
@8@s:8
Basic/MASM Far Externs
----------------------
Add these paragraphs to Section 20.3.3, "The Basic/MASM Interface."
When interfacing with Basic, all EXTERNs that are far must be
declared outside of a code or data segment.
This is incorrect:
.MODEL medium
.CODE
EXTERN StringAddress:FAR
This is correct:
.MODEL medium
EXTERN StringAddress:FAR
.CODE
New Command-line Options
------------------------
Add these paragraphs to Appendix C, "Generating and Reading Assembly
Listings."
With the PAGE directive, the default page length is 0 (infinite), and
the default page width is 0 (infinite). The allowable range of values
is 0 and 60-255 for page width, 0 and 10-255 for page length.
With the /Sf option, a first-pass listing will be generated even if
a fatal error occurs. The symbol table will be appended onto the end
of the listing file unless you give the /Sn option.
The first-pass listing is controlled by the same set of commands that
are used with the final listing.
Additional Error Messages
-------------------------
Add these new or changed error messages to Appendix F, "Error
Messages."
MASM fatal error A1006
invalid command-line option: 'option'
ML did not recognize the given parameter as an option.
This error is generally caused when there is a syntax error on the
command line. It can also be generated by trying to assemble multiple
assembly language files on the MLX driver command line.
MASM fatal error A1017
out of near memory
There was insufficient memory to assemble the program.
One of the following may be a solution:
- If you are using the NMAKE utility, try using NMK or
assembling outside of NMAKE.
- in PWB, try exiting and assembling using ML.
- In OS/2, try increasing the swap space.
- In DOS, remove terminate-and-stay-resident (TSR) software.
- If you have extended memory available, use the MLX.EXE driver.
- Change CONFIG.SYS to specify a lower number of buffers (the
BUFFERS= command) and fewer drives (the LASTDRIVE= command).
- Eliminate unnecessary INCLUDE directives.
MASM fatal error A1019
invocation failed : retry command line with /VM option
ML tried to restart itself with the /VM option but failed.
Enter the ML command line again, but add the /VM virtual-memory
option explicitly.
MLX fatal error A1800
processor not 80286 or above
You can only run MLX.EXE on an 80286 or above processor.
Use ML.EXE if you do not have an 80286 or 80386/486 processor.
MLX fatal error A1801
processor in protected or virtual 8086 mode
The MLX driver cannot run from XMS memory when in protected or
virtual 8086 mode.
MLX fatal error A1802
DPMI, VCPI, or XMS driver not installed
The MLX driver cannot find a compatible driver in memory.
You must have a DPMI, VCPI, or XMS driver, such as HIMEM.SYS,
installed before running MLX.EXE.
MLX fatal error A1803
unexpected initialization error
The MLX driver was unable to initialize the memory manager.
Make sure that you have a compatible DPMI, VCPI, or XMS driver
installed. HIMEM.SYS is a compatible XMS driver and is included in
this package.
MLX fatal error A1804
not enough near memory to load MLX.EXE
There was insufficient memory to start the DOS-extended assembler.
One of the following may be a solution:
- If you are using the NMAKE utility, try using NMK or
assembling outside of NMAKE.
- Remove terminate-and-stay-resident (TSR) software.
- Change CONFIG.SYS to specify a lower number of buffers (the
BUFFERS= command) and fewer drives (the LASTDRIVE= command).
MLX fatal error A1805
unable to run under Windows in standard mode
You can only run MLX.EXE in a Windows DOS box when running real or
386 enhanced mode.
MLX fatal error A1806
insufficient extended memory to load ML.EXE
There is not enough extended memory available to load the assembler
into high memory.
Change your configuration to give more memory to the DOS extender.
This may involve reducing the size of a RAM disk or cache.
MLX fatal error A1807
disk I/O error while loading program
The assembler encountered an error when trying to load ML into high
memory.
One of the following may be a cause:
- The disk has a bad sector.
- The file-access attribute is set to prevent reading.
- The drive is not ready.
MLX fatal error A1808
out of space in GDT
The MLX driver could not add enough entries to the Global
Descriptor Table (GDT).
You may be able to overcome this problem by rebooting your system
and running MLX.EXE before starting other programs.
MLX fatal error A1809
bad environment table
There was an invalid environment table passed to MLX.EXE.
The calling program passed a bad environment table. This error can
be caused by a corrupt version of COMMAND.COM.
MLX fatal error A1810
cannot load ML.EXE
The ML driver could not be found in the current path.
Make sure that the DOS version of ML.EXE was copied from the
distribution disks and is in the current path.
MLX fatal error A1811
ML.EXE not protected-mode compatible
An obsolete version of ML.EXE was found in the current path.
Make sure that the DOS version of ML.EXE was copied from the
distribution disks and is in the current path.
MLX fatal error A1850
unrecoverable fault
The MLX driver called ML.EXE, which generated a system error.
Note the circumstances of the error and notify Microsoft
Corporation by following the instructions in the Microsoft Product
Assistance Request form at the back of one of your manuals.
MASM error A2007
non-benign record redefinition
A RECORD definition conflicted with a previous definition.
One of the following occurred:
- There were different numbers of fields.
- There were different numbers of bits in a field.
- There was a different label.
- There were different initializers.
MASM error A2202
illegal use of segment register
You cannot use segment overrides for the FS or GS segment registers
when generating floating-point emulation instructions with the /FPi
command-line option or OPTION EMULATOR.
MASM error A2203
cannot declare scoped code label as PUBLIC
A code label defined with the "label:" syntax was declared PUBLIC.
Use the "label::" syntax, the LABEL directive, or OPTION NOSCOPED
to eliminate this error.
MASM error A2204
.MSFLOAT directive is obsolete : ignored
The Microsoft Binary Format is no longer supported.
You should convert your code to the IEEE numeric standard, which is
used in the 80x87-series coprocessors.
MASM error A2205
ESC instruction is obsolete : ignored
The ESC (Escape) instruction is no longer supported. All numeric
coprocessor instructions are now supported directly by the assembler.
MASM warning A4005
unknown default prologue argument
An unknown argument was passed to the default prologue.
The default prologue understands only the FORCEFRAME and LOADDS
arguments.
MASM warning A4013
line number information for segment without class 'CODE'
There were instructions in a segment that did not have a class
name that ends with "CODE". The assembler did not generate
CodeView information for these instructions.
CodeView cannot process modules with code in segments with
class names that do not end with "CODE".
MASM warning A4014
instructions and initialized data not supported in AT segments
An instruction or initialized data was found in a segment defined
with the AT attribute. The code or data will not be loaded at run
time.
Data in AT segments must be declared with the ? initializer.
MASM warning A6004
procedure argument or local not referenced
You passed a procedure argument or created a variable with the LOCAL
directive that was not used in the procedure body.
Unnecessary parameters and locals waste code and stack space.
MASM warning A6005
IF condition may be pass-dependent
Under the /Zm command-line option or the OPTION M510 directive,
the value of an IF condition changed between passes.
This error message may indicate that the code is pass-dependent and
must be rewritten.
H2INC fatal error HI1801
incomplete model specification
Only part of a custom memory-model specification was specified on
the command line.
When you specify a custom memory model with the /A command-line
option, you must specify code pointer distance, data pointer distance,
and DS register setup. This error is equivalent to the D2013 error
message for CL.
=================< Part 5: Using the DOS-extended assembler >===============
MLX: The DOS-Extended Assembler
-------------------------------
There is a new DOS-extended driver for ML called MLX. MLX loads
ML.EXE into high memory so that the assembler takes up very little
space in the first 640K of memory.
MLX uses extended memory to run ML in protected mode. If you have
multiple extended memory drivers available, MLX will select the
driver to use in this order:
- DPMI
- VCPI
- XMS
The HIMEM.SYS XMS driver is included in the MASM 6.0 package and
is automatically copied by setup into the real-mode executables
directory as MLX.EXE. To use HIMEM.SYS, put the following line
into your CONFIG.SYS file:
DEVICE = <path>HIMEM.SYS
Where <path> is the path to the location of HIMEM.SYS.
Use MLX only if running ML with the /VM virtual-memory option fails
due to an out of memory error. Because it runs in real mode, ML
with the /VM command-line option can run significantly faster than
MLX.
MLX Requirements
----------------
MLX requires an active DPMI, VCPI or XMS driver and at least 384K
of available extended memory to operate.
Differences between ML and MLX
------------------------------
The MLX DOS-extended driver can only assemble one source file at
a time. You must split multiple-file assemblies into several
invocations of MLX.
If you want to use MLX from the PWB command line, you must manually
change your makefile to reflect the name of the MLX driver. Change
the line:
ASM = ML
to
ASM = MLX
======================< Part 6: Changes to CMACROS.INC >====================
Using CMACROS.INC
-----------------
There is a new, MASM 6.0-compatible version of CMACROS.INC included
with the assembler. If you work with the Windows 3.0 Software
Development Kit, or the C 6.0 or FORTRAN 5.0 startup code, use the
new version of CMACROS.INC.
C and FORTRAN Startup Sources
-----------------------------
To build the C or FORTRAN start-up sources, change the ASMFLAGS line
of MAKEFILE from
ASMFLAGS= -Mx -Dmem_$(MODEL) -I$(INC)
to
ASMFLAGS= -Mx -Dmem_$(MODEL) -I$(INC) -DMS_STARTUP
=====================< Part 7: Known assembler bugs >===================
Ambiguous Radix Characters
--------------------------
The assembler accepts numeric characters outside the range of the
current radix. These characters are given their appropriate
values but are handled under the current radix. For example,
.RADIX 10
mov ax, 1F
mov bx, 1Fh
loads ax with 25 (10 from the tens digit and 15 from the ones).
The bx register is loaded properly.
