From: mmunson@animal.es.com (Mark Munson)
Subject: Re: Mac multitasking?
Reply-To: mmunson@animal.es.com (Mark Munson)
Organization: Evans & Sutherland Computer Corp., Salt Lake City, UT
Distribution: na
Date: Sat, 12 Dec 1992 00:52:08 GMT

In article <1992Dec11.073923.8502@athena.mit.edu> Eric M Hermanson responds:

MM> OK, let's see how this works.  Explain how object oriented technology solves
MM> this upgrade problem:  
MM>
MM> You've got a monochome display computer that is running a B&W paint program.
MM> Suddenly to decide to get color capabilities and a color monitor.  How do
MM> you get your current B&W paint program to support color?  Do you have to
MM> upgrade your software to take full advantage of the upgrade?

EH> With the Next, all color information is handled by the color panel (object).
EH> When NeXT upgraded the color panel to include PANTONE color support, ALL
EH> applications that had a color panel (or variation thereof) in them 
EH> automatically took advantage of this change.  Since the objects (in this
EH> case color panel) are bound (read in) at the run time of the program, the
EH> new color panel object popped up when the user selected "Color.." from 
EH> the menu.  This new color panel allowed the users to select colors through
EH> the PANTONE color matching system.  This is another advantage of NeXT.  It
EH> has PANTONE color support BUILT into the operating system.  ANY program
EH> may take advantage of it.  On the Mac, only programs that are WRITTEN to 
EH> have PANTONE color picking have it.  Object oriented technology makes
EH> programs very modular.  In this way, if a "module" is upgraded, ALL 
EH> applications benefit.  It is INHERENT in the operating system. 

Sort of begging the question aren't we?  If the program is a B&W paint
package, then why would there be a "Color.." selection on the window?

BTW:  The Macintosh also has a system color picker that is called by 
Applications.  This object can be replaced with other formats to allow
revisions of the color selection process.  Toolbox routines can be
replaced and upgraded.  If a Tool is upgraded, All Mac applications 
benefit.  It is INHERENT in the operating system.


MM>
MM> OK, let's say that you upgraded your OS to handle 8-channel sound sequences
MM> and MIDI data.  Would your current spreadsheet, wordprocessor, and database
MM> applications be able to take full advantage of the upgrade?  Or would each
MM> need to be modified to deal with improvements outside of their intended scope?
MM>
MM> Just wondering what you think?
MM>
MM> [MGM]


EH> Well, I am not sure why you want your word processor to handle MIDI data, but
EH> in any event, with NeXT, MIDI is fully supported by the operating system, 
    ^^^^^^^^^^^^
Side stepping the question again ;)

EH> built in.  NeXT has a built in Digital Signal Processor (DSP) Chip and MIDI
EH> driver for sound systhesis.  The DSP is a Motorola 56001.  As far as 
EH> MIDI and object oriented technology, NeXT has developed the Music Kit.  The
EH> Kit is full of prewritten objects that talk to MIDI devices and synthesize
EH> music.  If the objects are upgraded, music programs take advantage of the
EH> upgrade automatically.  The objects are inherent in the NeXT operating
EH> system.  Very modular, very upgradable.  Designed solidly from the GROUND UP.

Your original argument was that Mac applications had to be rewritten to take
advantage of new system features, and that NeXT computers didn't suffer from
this due to it's object oriented structure.  But what you just told me was that
you would have to upgrade or get new software to take advantage of new
modules, although replacing or upgrading a currently used module would
not require this.

This is exactly how the Mac works.  If I want new or upgraded features I can
just drop them (extensions) into the system.