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               OS/2...  What is it?  Do I need it?  Do I want it?

                               by Brooks McNeely,

                          from the PC Register, ETPCUG

        First let me say that I have been using OS/2 since October  1988,
        and  I  would never consider going back to DOS for  any  extended
        period.  Every OS/2 user that I have come in contact  with  feels
        the  same way. But with the large amount of misinformation  about
        OS/2  published  each month in various trade  publications,  most
        OS/2 users tend to be a little defensive and bring a zealotry  or
        religious  fervor to their discussions of OS/2. Hopefully  I  can
        refrain from such excesses.

        Well  then, what is OS/2? First let us consider some history.  In
        1984  IBM came out with the AT computer based on the Intel  80286
        chip. Shortly thereafter plans were made for a new version of DOS
        which  would take advantage of the advanced functionality in  the
        new chip. IBM contracted Microsoft for this new system and  prom-
        ised  many  of their large customers that IBM would bring  out  a
        system  which  would  work on 80286 computers.  Before  this  new
        system  ever  even reached an announcement stage,  IBM  delivered
        their  next generation of PC called the PS/2, based on  both  the
        80286 chip and the newer 80386 chip. Several months later IBM and
        Microsoft announced the new operating system (OS) and its first 4
        incarnations. The original development effort occurred during the
        period from 1985 to 1987. IBM and Microsoft announced the  sched-
        ule  of  the first 4 releases in early 1987 (SE 1.0, SE  1.1,  EE
        1.0,  EE  1.1)  and SE 1.0 actually shipped  early.  EE  1.0  was
        several months late, but the SE 1.1 and EE 1.1 releases were very
        close to the schedule.

        The  original 8086 chip had a segmented memory  architecture  re-
        quiring  two 16 bit words to be combined to  generate  addresses.
        Within  a  64K  block of code, the memory could  be  accessed  by
        simpler  instructions, not requiring this  combination  overhead.
        (The  original  IBM  PC used the 8088 chip which  had  a  similar
        relation to the 8086 as the 80386SX has to the 80386DX chip). The
        80286 could emulate the earlier 8086 chip by running in what  was
        called REAL mode. In addition, it could also multitask in PROTECT
        mode  where it could access 16 megabytes of memory per task  with
        hardware protection between tasks. The 80386 chip can emulate the
        earlier chips plus added at least three new modes. One mode  also
        has  a segmented architecture that allows  multitasking  address-
        ability  of 64 terabytes (trillion) of virtual memory;  a  second
        mode  is a non-segmented, FLAT memory model which  allows  direct
        addressability  to 4 gigabytes (billion) of virtual memory  (this
        is  the primary mode for OS/2 2.0). Finally, in order to  correct
        the  problems associated with running REAL mode  applications  on
        the  80286,  a new "virtual" REAL mode emulation mode  was  added
        with  the added advantage that multiple instances  are  available
        with full protection.

        Early delays were caused by the difficulty in providing transpar-
        ent  compatibility running DOS programs on the 80286 chip.  Rumor
        has  it that Microsoft wanted to bypass the 80286 and  make  OS/2
        80386 specific, but IBM insisted on honoring their commitment  to
        their  80286 customers. OS/2 1.x is totally compatible  with  the
        80286  chip and will run acceptably on an original IBM PC  AT  (6
        mhz). Unfortunately few people with this hardware are  interested
        in running OS/2.

        IBM and Microsoft made many mistakes in their original marketing,
        primarily  because they felt that most users would recognize  the
        obvious advantages of OS/2 and would convert en masse. One of the
        biggest  mistakes  was  in the name -DOS 5.0 would  have  been  a
        natural,  but IBM especially wanted a new name they could  trade-

        mark, plus OS/2 would associate the system with their new line of
        personal  computers  -the  PS/2. (This turned out  to  hurt  OS/2
        because many users to this day think that OS/2 will only run on a
        PS/2).  Curiously, the trade press at the time reported the  name
        of the new OS would be DOS 5, DOS 286, CP/DOS, AOS, and others.

        Microsoft  would  finish a release of OS/2, ship it  to  IBM  for
        their internal testing and modifications to take advantage of IBM
        hardware,  then  when IBM availability was  announced,  Microsoft
        would send OS/2 to other OEM licensees for similar  improvements.
        This would give IBM a head start (and marketing advantage).  This
        advantage, plus the lack of any mass adoption of OS/2 caused  the
        OEM's  to not emphasize OS/2. Many OEM's never shipped a  release
        past  1.1 and some never shipped a version at all. Most  releases
        were at least 6 months or longer after the IBM version.

        Some of OS/2's perceived drawbacks were considered its strengths.
        Being  a  multitasking  operating system,  applications  are  not
        allowed to write directly to the hardware since another  applica-
        tion  may  also  be using the hardware  concurrently.  OS/2  will
        intercept  such  requests  and communicate to  the  hardware  via
        device drivers. Any new device can be added to an OS/2 system  by
        merely supplying a suitable device driver. Without any  marketing
        pressure, many hardware vendors have never provided OS/2  drivers
        for  their hardware. Unless the hardware mimics a device  with  a
        pre-existing  driver  closely enough, the device cannot  be  used
        under OS/2. These problems can be irritating enough with  devices
        like  fax  boards,  printers, CD-ROM drives, etc.  But  when  the
        drivers  for hard disk controllers, video adapters,  floppy  disk
        controllers, and sometimes even keyboards or mice are not  avail-
        able, OS/2 will simply not run on a system. This widespread  lack
        of hardware support is the basis for the myth that OS/2  requires
        IBM hardware. IBM generally supplies device drivers for their own
        hardware,  but  sometimes handles their own  hardware  with  BIOS
        extensions  to  make the device look like a  generic  device  for
        which OS/2 provides intrinsic support.

        Many  people are using IBM's version of OS/2 on no  name  clones,
        but  IBM, reasonably enough, cannot promise that it will run  (or
        if it runs now, if it will run the next release). So even if OS/2
        is infinitely extensible with devices not even invented yet, many
        common  devices  cannot be used without a driver. Still,  if  IBM
        cannot test their modifications on other OEM hardware, and if the
        hardware  vendor  does not supply their version  of  OS/2,  IBM's
        version is probably the only choice, but with no guarantees.

        A company negotiating a large purchase of PC hardware, can  often
        require  that  the  hardware run IBM's OS/2.  For  an  individual
        without  this  leverage buying a system for OS/2, the  hard  disk
        controller  and super VGA video adapter card are most  likely  to
        cause  problems.  The newer SCSI adapter cards seem to  have  the
        most problems without a specific device.

        IBM's version of OS/2 1.x comes in two flavors, Standard  Edition
        (SE)  and Extended Edition (EE). SE is the base system, while  EE
        is an IBM only version which includes the base system in SE, plus
        two  OS/2 applications -Database Manager (DM) and  Communications
        Manager  (CM). In addition a LAN Requester function is  available
        under  EE which allows access to IBM's LAN Server product. DM  is
        the functional equivalent of IBM's premier relational database on
        mainframes -DB2. There is a high performance SQL database engine,
        the Query Manager front end, and a Remote Data Services  distrib-
        uted  database  component. CM is  a  multifaceted  communications
        package  with the broadest support of protocol  layers  available
        under  OS/2. The mainframe communications are excellent, but  the
        asynchronous communications is based on either VT100 or IBM  3101
        terminal  emulation with only XMODEM and mainframe file  transfer
        capability.  It is not nearly as complete as the 3270  emulation.
        IBM offers a complete TCP/IP package separately.

        The original OS/2 Version 1.0 had only a character mode interface
        like  DOS.  Beginning  with Version 1.1 (shipped at  the  end  of
        1988), OS/2 had a graphical user interface (GUI) known as Presen-
        tation Manager (PM). PM was a combination of Microsoft's  Windows
        technology, IBM's mainframe graphics technology GDDM, plus exten-
        sions available as a result of the
        added  features  of the OS/2 kernel. Some people equate  an  OS/2
        application  with  a PM application.  Although  this  distinction
        ignores the benefits of OS/2 to non-GUI applications, PM programs
        are better able to take advantage of the multiple threads  avail-
        able to OS/2 processes.

        OS/2  provides  preemptive multitasking even on the  80286  plat-
        forms. By preemptive, we mean that multiple tasks can be  coordi-
        nated better and more smoothly (tasks can be easily interrupted).
        Although an OS/2 program can be written to monopolize  resources,
        most  programs run well without tuning. With Windows  3.0  multi-
        tasking  can  only occur in ENHANCED mode,  on  80386  computers,
        under  what is euphemistically called  cooperative  multitasking.
        What  this means is that under Windows, programs have to  be  de-
        signed to multitask well with other programs. Most Windows appli-
        cations  are not designed this way. Said another way, under  OS/2
        programs  can be interrupted by the system, under Windows a  pro-
        gram has to release its control so other programs can run.

        Another  difference  with DOS-based programs is that  under  OS/2
        hardware generates interrupts which can then be processed by  the
        system. Under DOS, programs often poll hardware to determine when
        further  processing is necessary. This polling causes DOS to  use
        much  more  CPU resources than OS/2. This means little in  a  DOS
        single-tasking environment, but can be a performance killer in  a
        multitasking  environment.  As an example, assume I'm  running  a
        word  processor,  and  it is waiting on my  next  keystroke.  The
        program  might check the keyboard controller, "Got  anything  for
        me?  No. Hmmm, better try again. Got anything for me?  ....",  ad
        infinitum. If the machine is also running a database sort,  back-
        ground  communications, etc at the same time, this  tight  little
        loop  will adversely affect the performance of these other  jobs.
        In OS/2, the processor is freed for other work until the keyboard
        is  struck and an interrupt is generated to signal the  operating
        system that there is something to do in the word processor  task.
        One  common reason for printer problems under OS/2 is  that  some
        cheap parallel printer cables do not have all the pins  function-
        al.  They work fine under DOS, but do not signal conditions  that
        cause  OS/2 interrupts. Under OS/2 2.0 a number of  DOS  settings
        are configurable to control gluttonous DOS programs.

        Many small utility programs that require TSR's under DOS are easy
        to  implement under OS/2. Several facilities are available  under
        1.3  that are only available as TSR's under DOS. One useful  fea-
        ture is the command line history buffer. Previous commands can be
        paged through using the cursor keys, and full editing of previous
        commands  is  easy using insert, delete,  backspace,  and  cursor
        keys.  Another  utility is one which will lock the  keyboard  and
        mouse after a specified interval of inactivity. A screen  blanker
        is  also included. Many of these niceties are recently  available
        in DOS 5.0 and DR-DOS and earlier in other utility packages,  but
        they are part of OS/2 and mostly have been for some time.

        There  are several shortcomings and restrictions with  OS/2  1.3.
        Early  versions  were plagued by poor printer support,  but  most
        popular  printers are now supported. The biggest problem  is  the
        lack of applications. There are OS/2 versions of many DOS charac-
        ter  based  applications  including:  WordPerfect  5.0,   Paradox
        (Version  2), PkZIP, ARC, RBASE, Lotus 123, Microsoft Word,  etc.
        There  are  some PM applications  available  including  Microsoft
        Excel  and Word, 123/G, Freelance, CorelDraw, Describe Word  Pub-
        lisher, PageMaker 3.0, Ventura Publisher, etc. Some of these  are
        pure  PM  applications, and some are Windows programs  ported  to
        OS/2  using Microsoft's earlier Software Migration Kit  (SMK)  or
        Windows  Library for OS/2 (WLO). The problems with WLO  ports  of
        Windows programs is that they typically do not take advantage  of
        OS/2  features  like multi-threading, and they seem to  run  less
        efficiently than native PM applications.

        Another problem is the restrictions on the DOS compatibility box.
        Although  the  DOS box is given 640K, the amount of  free  memory
        available is usually 20K -40K less than a real DOS machine, since
        the OS/2 Device Drivers are resident in the lower 640K of memory.
        This  produces an integrity vulnerability since a misbehaved  DOS
        program can corrupt the OS/2 device drivers and crash the system.
        Additionally  the  DOS box is active only when it has  the  fore-
        ground  focus.  OS/2 programs continue to execute  in  the  back-
        ground, but when the DOS session is placed in the background,  it
        is suspended. This is the reason that communications programs are
        not considered to operate reliably in the DOS box. TSR's and some
        programs that require direct access to the hardware may not work.
        I  CAN say that all the programs I have tried do work in the  DOS
        box.

        OS/2 was designed from the beginning to be a single-user,  multi-
        tasking operating system as similar and backwardly compatible  as
        possible  to  DOS, but free of the memory restrictions  and  with
        added functionality and integrity. It was designed to work better
        in  the single-user, multitasking environment than either DOS  or
        UNIX, while retaining much of the same command interface as  DOS.
        Since  version  1.2 OS/2 has offered the  High  Performance  File
        System  (HPFS) as an option for fixed disks. HPFS  offers  higher
        performance, better integrity and recoverability, long file names
        (254  characters), extended attributes (EA's). With OS/2  EE  1.2
        and  both  1.3  releases IBM has  supplied  Procedure  Language/2
        (REXX). This is a replacement for the DOS and OS/2 batch language
        with much greater functionality and programmability.

        The advantages of OS/2 become more apparent the more you use your
        computer.  For  software developers OS/2 is almost  a  necessity.
        Some  people recommend OS/2 only for server applications, but  it
        is  much  more  valuable in a user environment.  The  ability  to
        multitask  dramatically  changes the way one uses  the  computer.
        "Why do I need multitasking? I never do more than one thing at  a
        time."  I felt this way once myself, and maybe it's true most  of
        the  time. But there are those not too infrequent times  that  we
        have to do those menial tasks associated with computing -backups,
        downloads,  formatting diskettes, printing, etc. And we are  tied
        to our computers waiting for it to finish so we can go on to  the
        next  thing  we  need to do. One afternoon several  weeks  ago  I
        noticed  that  I was in the middle of a download of a  200K  file
        from  a  BBS, copying a 100 page ASCII text file to  my  printer,
        writing a document in WordPerfect, and occasionally switching  to
        a  command line session to format some diskettes to copy  what  I
        was downloading. During this time I had a call about changing the
        nightly DB2 backups at K25. While all this was running, I  logged
        on to the K25 MVS system and updated a DB2 table in a 3270  wind-
        ow.  Admittedly this extent of overlap in my work doesn't  happen
        that often, but it soon becomes second nature when it does.

        IBM  has announced the next generation of OS/2. Version 2.0  will
        ship at the end of March 1992. It will require an 80386 processor
        and  will  fix  most of the problems with the  DOS  emulation  in
        versions 1.x. It will allow the multitasking of DOS applications,
        use  of  EMS  and XMS memory, greater than 620K  of  free  memory
        counting network drivers, the use of DOS-specific device drivers,
        the  ability  to boot specific DOS versions (or even  DR-DOS)  if
        necessary for certain applications. Windows 2.x and 3.0  applica-
        tions will run in these boxes transparently and with interprocess
        communication  with  PM programs (and without having  to  install
        Windows).  It will support programs written for the 32  bit  FLAT
        memory  model, as well as older 1.x 16 bit programs.  Because  of
        compatibility problems with other vendors hardware, IBM is trying
        to  verify OS/2 on many of the major clone companies'  computers.
        Instead  of  having a separate EE package, IBM will offer  a  new
        product  called Extended Services (ES) which will run on  top  of
        IBM  and other vendors' OS/2. ES Version 1.0 will still be  a  16
        bit application and can run under 2.0 or on 1.x. ES will  contain
        DM  and CM. The LAN Requester product will be packaged  with  the
        LAN Server product. Due to user request, ES will be split up into
        separate DM and CM products by the end of 1992.

        Another new feature in 2.0 is the addition of the WorkPlace Shell
        (WPS). This is a chameleon-like shell that is object-oriented and
        somewhat  reminiscent of the Macintosh. But it can be  configured
        to look and operate similarly to OS/2 1.x, Windows Program Manag-
        er,  DOS, and maybe even the Mac itself. This shell is a  glimpse
        of  the  future and is based on earlier work in  a  collaborative
        effort with Metaphor Corporation originally for the  OfficeVision
        product.

        Although  OS/2 can be criticized because of past mistakes by  IBM
        and Microsoft, its past, present, and future all contain elements
        to admire. IBM did produce the best OS system available today for
        80286  computers; one that takes advantage of the  80286  PROTECT
        mode -OS/2 1.3. Thus far IBM has provided FREE upgrades for  each
        new  release  of  OS/2 (I originally got 1.0  and  have  upgraded
        successively  to 1.1, 1.2, and 1.3). IBM has announced  that  the
        upgrade from 1.x to 2.0 will also be free. Owners of EE will  get
        a  free  upgrade to OS/2 2.0 and ES 1.0. Earlier  this  year  IBM
        reduced the price of OS/2 1.3 SE to $149, with a $99 upgrade from
        any  IBM  version of DOS. With a free upgrade to 2.0, this  is  a
        great  deal. When it ships in March OS/2 2.0 will have  a  retail
        price  of $199. IBM has stated that future  object-oriented  (OO)
        operating systems in development internally and in the IBM -Apple
        collaboration  will be able to run OS/2 applications.  OS/2  will
        continue to evolve over the next few years and will not be pushed
        into obsolescence.

        Compared  to Windows 3.x, OS/2 offers better integrity and  reli-
        ability. It more fully exploits the capabilities of modern  hard-
        ware.  Depending somewhat on the implementation, OS/2 offers  the
        capability  of much better performance, and this performance  gap
        will increase with OS/2 2.0. Windows has much better  application
        availability  and hardware support, but with its obvious  limita-
        tions  (mostly because of its reliance on DOS as a base),  Micro-
        soft  is  promoting  its Windows NT as the  next  generation  OS.
        Windows  NT is actually Microsoft's version of OS/2 with  the  PM
        API's removed and replaced by Windows API's. In theory it will be
        more  modular, but its final form and capabilities are  still  in
        flux. A good deal of speculation has been present concerning when
        Windows NT will be available. The current Windows magazine states
        3rd Quarter 1992 (within 3 months of OS/2 2.0 in one  editorial);
        more pessimistic observers have projected 4th Quarter 1993.  With
        the recent failures by Apple, IBM, Lotus, Microsoft, WordPerfect,
        etc. to meet stated shipment dates, I'm more inclined to  believe
        that Windows NT is still over a year away.

        As  an  early  Windows user (1.0 through 2.1  -by  the  time  3.0
        shipped  I  had found OS/2), and a long time IBM  mainframe  user
        (since  1966), I feel that I can better rely on IBM's  statements
        concerning  the future than Microsoft's. As a long time user  and
        fan  of  Excel  and the Microsoft C compiler,  I  am  reluctantly
        having  to abandon them as Microsoft childishly refuses to  allow
        these products to support OS/2 in the future so as to not  appear
        to  legitimize IBM's competitive system. When Microsoft  released
        Windows  3.0, most Windows applications could not run without  an
        upgrade.  I can still run programs I wrote, compiled, and  linked
        in  1970 on the latest and greatest IBM mainframe (not that  this
        is  uniformly  positive). Clearly IBM has  orphaned  some  highly
        touted systems in the past, but they also take public commitments
        more seriously than Microsoft.

        If  you  want to run an advanced operating system with  the  most
        compatibility  to  DOS; if you want to run a  system  that  fully
        utilizes  your  hardware investment; then try OS/2. What  do  you
        need? For 2.0 you will need at least an 80386SX. The more  memory
        the better the performance -I consider 4Mb an acceptable  minimum
        (1.3  will  run in 2Mb, 2.0 will need  approximately  3Mb).  Over
        committed  memory  will be written to a swap file  on  disk,  but
        applications  will  slow dramatically. Count on 12Mb to  20Mb  of
        hard  disk space for the base system. Additionally you will  need
        extra space for the swapper file (to be conservative, 8Mb to 16Mb
        would be nice on a 4Mb system). Clearly the entry point for  OS/2
        is  higher  than for Windows, but for all of you  actually  using
        Windows  and Windows applications, these are about the  same  re-
        quirements  that Windows REALLY needs. Try OS/2 for a  couple  of
        months and you too will share my enthusiasm for the system.