Re: Why couldn't an operating system be written in ada

["Robert C. Leif, Ph.D." <rleif@MAIL.CTS.COM>]

The following appeared on Comp.Lang.Ada
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Date:    Mon, 15 Jul 1996 02:12:25 GMT
From:    Nasser Abbasi <nasser@APLDBIO.COM>
Subject: Re: Why couldn't an operating system be written in ada

   >From: Mark  McKinney <mckmark@mail.concentric.net>


  Mark  McKinney> > It has been claimed that the capability to interface
with other  >>languages  is a great asset to ada. Sometimes interfacing can
be a tremendous
> > liability. Besides the OS could perform most of work that the language
>> runtime does. So why not build an OS in ADA?
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Nasser Abbasi >The question should be: why build another OS ? we already have
>too many.
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The question, "So why not build an OS in ADA"? requires more than a yes or
no response.

Firstly, one should define, what constitutes an operating system. Then, one
should determine what parts will be improved by recreating and redesigning
them in Ada.

Since Windows is the best selling operating system, I will take the liberty
of offending some of you by defining an operating system as what one
purchases when buying Windows. This is NOT meant as an endorsement of
Microsoft's code.

Component               Should be Ada       Comment
---------------                 ---------------------
Executive (core).          Yes
GUI                                 Needs a binding.
Device Drivers              Use off the shelf. If not available,  create in Ada.
Applets                          Use what is provided.
File System                   Use what is provided, and if necessary, add
Ada enhancements.
Ada POSIX Binding     Would help.

Executive: I suspect that for both real-time systems and pseudo embedded
systems where the operating system only runs one application. These include
medical instruments and other dedicated devices.

GUI: I would prefer a thick binding for my applications. The use of some
standard to permit portability will greatly help. My present guess is that
HTML will be the successful portable solution.

Device Drivers: A major real advantage of Windows is the availability of
device drivers. Parenthetically, the major disadvantage of Ada is the lack
of device drivers for boards, such as analog to digital converters,
printers, and high resolution displays.

The only applets from Windows, where Ada would obviously help are those to
do with communication. Applets such as games, screen savers, and file viewers

The Windows 95 Explorer is a great improvement. However, a database based
system would be a further improvement.

Ada POSIX bindings would increase portability. I quite well understand that
it is probably too costly to provide a complete POSIX binding. However,
where possible, the Ada POSIX binding syntax should be employed. The
exceptions: Can_Not_Be_Implemented or Not_Implemented probably will need to
be created and used fairly often.

Lastly, I wish to emphasize that the present GUIs are often far beyond the
capabilities of most users. Many individuals, including some of considerable
ability in other fields, are still quite happy with DOS applications, such
as WordPerfect. A 32 bit version of DOS might still be a profitable enterprise.

Robert C. Leif, Ph.D.

Robert C. Leif, Ph.D., PMIAC,
Vice President & Research Director
Ada_Med, A Division of Newport Instruments
Tel. & Fax (619) 582-0437