Re: Ada Run-time for embedded systems

[CONDIC@PSAVAX.PWFL.COM]

From: Marin David Condic, 407.796.8997, M/S 731-93
Subject: Re: Ada Run-time for embedded systems
Original_To:  PROFS%"SMTP@PWAGPDB"
Original_cc:  CONDIC



Garlington KE <l107353@CLIFFY.LFWC.LOCKHEED.COM> Writes:
>
>: I don't know how y'all would like to define what an "embedded"
>: system is, but I'd say that if it has a screen, QWERTY keyboard
>: and a mouse, we're _probably_ not talking about one.
>
>"Probably" is right! The Automated Target Handoff System in the AFTI/F-16
>aircraft has a screen (head-down display), an alpha-numeric keyboard (for
>sending messages to the target designator on the ground), and a mouse (a
>cursor slew on the stick). A user interface is _not_ a determinant of
>"embedded." Furthermore, "Embedded" and "Real-time" have nothing to do with
>each other.
>
O.K. I *did* include the "Probably" proviso for a good reason -
there's always exceptions.

I've worked on avionics which have had CRT displays for the pilot
and buttons which they could push to get behavior from the
system - I'd still call that "embedded" even though it
technically speaking has a screen and a keyboard. I think you're
missing my point:

Plugging a Sun/Unix workstation into an aircraft via a 1553 bus
does not seem to me to constitute an "embedded" system - even
though, as you observe, it might very well be considered a
"realtime" system.

I think my point was to observe that the word "embedded" and the
word "realtime" tend to get abused rather badly and this can
confuse the discussion - especially as it related to the original
theme of COTS on "embedded" machines. I'd still like to ask if
anyone has an effective definition of either term such that it
can exclude from the discussion IBM mainframe payroll programs.
(Of course, there are always us obstinate Philidelphia Lawyers
who'd argue the point just to be arguing something! ;-)

I personally think some of the attributes of an "embedded
computer" probably (and note my equivocation - PROBABLY) ought to
include the following:

    * It is physically contained within a machine or device.

    * The purpose of the machine or device is something other
      than computing.

    * The computer controls or influences or monitors the
      behavior of the machine or device.

    * The computer is dedicated to and specifically designed for the
      control/influence/monitoring of the machine or device.

    * The computer's software is dedicated to and specifically
      designed for the control/influence/monitoring of the
      machine or device.

    * Both the computer and it's software are optimized for their
      designed task. (Id est, neither contains stuff which isn't
      related to the task, except by accident.)

I don't know if anyone else would consider this list sufficient
or accurate, but if you'd accept these points as significant, it
makes it difficult to talk about IBM-PClones running MS-DOS being
"embedded" computers. It also reduces - if not eliminates - the
possibility of COTS being installed on an "embedded" machine.

Pax,
Marin

Marin David Condic, Senior Computer Engineer    ATT:        407.796.8997
M/S 731-93                                      Technet:    796.8997
Pratt & Whitney, GESP                           Internet:   CONDICMA@PWFL.COM
P.O. Box 109600                                 Internet:   MDCONDIC@AOL.COM
West Palm Beach, FL 33410-9600
===============================================================================
    "There are like two kinds of jobs: One is called 'Jobs,' which is
    for jobs that suck, and the other kind is called 'Careers,' which
    also suck, but for longer."

        --  Beavis & Butt-Head
===============================================================================