MS-DOS/v2.0/source

                         MSDOS 2.0 RELEASE





The 2.0 Release of MSDOS includes five 5 1/4 double density single sided

diskettes or three 8 iinch CP/M 80 format diskettes.



The software/documentation on the five inch diskettes is arranged

as follows:



1.   DOS distribution diskette.  This diskette contains files which

     should be distriibuted to all users.  This allows the DOS distri-

     bution diskette to meet the requirements of users of high level

     language compilers as well as users running only applications.

     Many compilers marketed independently through the retail channel

     (including those of Microsoft) assume LINK comes with the DOS, as

     in the case of IBM.  How you choose to distrubute BASIC (contracted

     for separately) is up to you.



2.   Assembly Language Development System diskette.  This diskette

     contains files of interest to assembly language programmers.

     High level language programmers do not need these programs unless

     they are writing assembly language subroutines.  IBM chose to

     unbundle this package from the DOS distribution diskette (except

     for DEBUG), but you do not have to do so.



3.   PRINT and FORMAT diskette.  This diskette contains .ASM source

     files which are necessary to assemble the print spooler, which you

     may wish to customize for greater performance.  .OBJ files are also

     included for the FORMAT utility.



4.   Skeltal BIOS and documentation diskette.  This diskette contains

     the skeltal BIOS source code and the SYSINIT and SYSIMES object

     modules which must be linked with your BIOS module.  The proper

     sequence for linking is BIOS - SYSINIT - SYSIMES.

     A profiler utiliity is also included on the diskette, but this

     is not intended for end-users.  This is distributed for use by

     your development staff only and is not supported by Microsoft

     If you do decide to distribute it, it is at your own risk!





5.   Documentation.  Features of 2.0 are documented on this disk.



The user manual contains some significant errors.  Most of these are

due to last minute changes to achieve a greater degree of compatibility

with IBM's implementation of MS-DOS (PC DOS).  This includes the use

of "\" instead of "/" as the path separator, and "/" instead of "-"

as the switch character.  For transporting of batch files across

machines, Microsoft encourages the use of "\" and "/" respectively

in the U.S. market.  (See DOSPATCH.TXT for how you can overide this.

The user guide explains how the end-user can override this in CONFIG.SYS).

Both the printer echo keys and insert mode keys have now been made to

toggle.  The default prompt (this may also be changed by the user

with the PROMPT command) has been changed from "A:" to "A>".

We apologize for any inconveniences these changes may have caused

your technical publications staff.





Here is what you need to do to MSDOS 2.0 to create a shipable product:

(see "Making a Bootable Diskette" below)



1.  BIOS.  If you have developed a BIOS for the Beta Test 2.0 version

    You should link your BIOS module to SYSINIT.OBJ and SYSIMES.OBJ.

    You must modify your BIOS to accomodate the call back to the BIOS

    at the end of SYSINIT.  If you have no need for this call, simply

    find a far RET and label it RE_INIT and declare it public.

    An example of this can be found in the skeletal BIOS.  In addition

    please add support for the new fast console output routine as

    described in the device drivers document.  We strongly recommend

    that you adapt the standard boot sector format also described in

    device drivers.  Once again, please refer to the skeletal BIOS.

    If you have not yet implemented version 2.0 please read the device

    drivers document.  Microsoft strongly recommends that machines

    incorporating integrated display devices with memory mapped video

    RAM implement some sort of terminal emulations through the use of

    escape sequences.  The skeletal  BIOS includes a sample ANSI

    terminal driver.



2.  Please refer to DOSPATCH.TXT for possible changes you might wish

    to make.  We strongly recommend that you not patch the switch

    characters for the U.S. market.  Your one byte serial number

    will be issued upon signing the license agreement.  Please patch

    the DOS accordingly.  If you wish to serialize the DOS, this is

    described in DOSPATCH.TXT.  Please patch the editing template

    definitions.  Please note the addition of the Control-Z entry

    at the beginning of the table.   Also note that the insert switches

    have now both been made to toggle.



3.  Utilities.  FORMAT must be configured for each specific system.

    GENFOR is a generic example of a system independent format module,

    but it is not recommended that this be distributed to your customers.

    Link in the following order:  FORMAT, FORMES, (your format module).

    The print spooler is distributed as an executable file, which only

    prints during wait for keyboard input.  If you wish with your

    implementation to steal some compute time when printing as well,

    you will need to customize it and reassemble.  Please note that

    you can use a printer-ready or timer interrupt.  The former is more

    efficient, but ties the user to a specific device.  Sample code

    is conditionaled out for the IBM PC timer interrupt.



The following problems are known to exist:



1.  Macro assembler does not support the initialization of 10-byte

    floating point constants in 8087 emulation mode - the last two bytes

    are zero filled.



2.  LIB has not been provided.  The version which incorporates support

    for 2.0 path names will be completed in a couple of weeks.  The

    1.x version should work fine if you cannot wait.  Because the library

    manager acts as a counterpart to the linker, we recommend that it

    be distributed with the DOS distribution diskette as opposed to the

    assembly language development system.



3.  International (French, German, Japanese, and U.K.) versions will be

    available in several months.



4.  COMMAND.ASM is currently too large to assemble on a micro.  It is

    being broken down into separate modules so it can be asembled on

    a machine.  Source licensees should realize that the resultant

    binaries from the new version will not correspond exactly to the

    old version.



5.  If you have any further questions regarding the MSDOS 2.0 distribution

    please contact Don Immerwahr (OEM technical support (206) 828-8086).





    Sincerely yours,





    Chris Larson

    MS-DOS Product Marketing Manager

    (206) 828-8080







            BUILDING A BOOTABLE (MSDOS FORMAT) DISKETTE





1.  In implementing MSDOS on a new machine, it is highly recommended

    that an MSDOS machine be available for the development.

    Please note that utilities shipped with MSDOS 2.0 use MSDOS 2.0

    system calls and WILL NOT not run under MSDOS 1.25.



2.  Use your MSDOS development machine and EDLIN or a word processor

    package to write BOOT.ASM, your bootstrap loader BIOS.ASM and

    your Format module.



3.  Use MASM, the Microsoft Macro-86 Assembler, to assemble these

    modules.  LINK is then used to link together the .OBJ modules in

    the order specified.



4.  Link creates .EXE format files which are not memory image files

    and contain relocation information in their headers.  Since your

    BIOS and BOOT routines will not be loaded by the EXE loader in

    MSDOS, they must first be turned into memory image files by

    using the EXE2BIN utility.



5.  The easiest thing to do is to (using your development machine)

    FORMAT a single sided diskette without the system.  Use DEBUG

    to load and write your BOOT.COM bootstrap loader to the BOOT

    sector of that diskette.  You may decide to have your bootstrap

    load BIOS and let the BIOS load MSDOS or it may load both.  Note that

    the Bootstrap loader will have to know physically where to go on

    the disk to get the BIOS and the DOS.   COMMAND.COM is loaded

    by the SYSINIT module.



6.  Use the COPY command to copy your IO.SYS file (what the

    BIOS-SYSINIT-SYSIMES module is usually called) onto the disk

    followed by MSDOS.SYS and COMMAND.COM.   You may use DEBUG

    to change the directory attribute bytes to make these files hidden.



CAUTION:



At all times, the BIOS writer should be careful to preserve the state

of the DOS - including the flags.  You should be also be cautioned that

the MSDOS stack is not deep.  You should not count on more than one or

two pushes of the registers.

�����������������������������������������������������������������������������������