TweetFollow Us on Twitter

June 93 - BE OUR GUEST

BE OUR GUEST

SYSTEM ENABLERS

C. K. HAUN

[IMAGE 107-108_Guest_col_rev1.GIF]

System 7.1 introducedsystem enablersto Macintosh system software architecture. Since their introduction on some of Apple's new machines, there's been some confusion about what system enablers are for, and developers have expressed interest in writing and using them. This column will shed some light on the subject.

THE BAD NEWS
Even before beginning to describe them, we have to emphasize that system enablers aresystem software,designed and intended solely for the use of Apple Computer. Detailed descriptions of their design and use will not be released. Their functionality and implementationwillchange; any developers who try to decipher enablers and implement their own are warned that they will fail in future system releases. Donot write your own enabler or modify a current one!

Kinda harsh, huh? But we really mean it: the functionality of system enablers makes sense only for system software. Also, modifying or creating an enabler without fully understanding how one works could cause the enabler mechanism to fail silently. This could result in a machine that appears to be working correctly but does not have the full enabler functionality active, causing very hard-to-isolate crashes or other problems.

OK, SO WHAT ARE THEY?
System enablers (which were called "gibblies" in early documentation and system development releases) replace the release strategy that Apple used in the past for minor system changes needed for new hardware. The old strategy was to release a new version of the system software, such as version 6.0.8 or 7.0.1. With enablers, the differences in hardware no longer require a new system release, but instead each new machine has its own enabler (if necessary) to make the system work for that hardware.

This change was made for two reasons:

  • Creating an enabler instead of a whole new system release reduces Apple's quality assurance and testing time. By creating an enabler, we're testing new code only on new machines; past machines aren't affected since the new enabler won't run on those machines. This also reduces your testing time as a third party, since you no longer have to install a new system release on all your older machines and test for compatibility; you know the system changes will affect only the newly released machines.
  • Enablers reduce user confusion and unnecessary upgrades. In the past, every time a machine was released, with its corresponding new software release, users of older machines were unsure whether they needed to upgrade to the new system. Many assumed that since it was newer, it was better. While this has been true occasionally, it usually isn't (upgrading from 7.0 to 7.0.1 on a Macintosh IIcx, for example, gives the user nothing new).

Apple will continue to use system extensions or components when new functionality is being added across the product line, as with QuickTime and Macintosh Easy Open. Enablers just broaden the range of options for enhancing the user's environment.

HOW DO THEY WORK?
Nope, no cheating -- we really won't be describing the internals of enablers. But here are some general rules about their behavior.

An enabler is essentially an extension to the System file; from a programmatic standpoint itis the System file. The Resource Manager was changed slightly to recognize references to the System file (CurResFile(0), for example) as being references to the System fileandthe current enabler. The code or other resources included in the enabler file appear to actually reside in the System file.

Any new machine may have a system enabler. The enabler will contain the system-level code necessary to implement changes required for that machine. A single enabler may be used for a family of machines, or a separate enabler may be created for each new machine.

If there are multiple enablers in a machine's System Folder, the system will use onlyoneof them. The system software (System file plus enabler) is responsible for arbitrating which enabler is used on a specific machine. It looks at the machine type it's currently running on, the machines that the enabler supports, and some enabler-internal applicability flags. Note that this is how the decision is currently made; as enablers are used for more machines and in different situations, more variables may be added to the decision process.

ENABLERS AND REFERENCE RELEASES
A specific enabler may not stay around forever. Apple has announced its intention to have "reference releases" every year to 18 months; these are the system upgrades that all users will be encouraged to install. Some enablers may be rolled into a reference release, so a machine that needed an enabler for System 7.1 may not need one for System 8. This is not a hard and fast rule; some enablers may stay around forever, depending on the functionality they enable.

THE BOTTOM LINE
System enablers make everyone's life easier by encapsulating system changes for new machines in one place. But they are not for non-Apple use, and developers cannot implement them with any hope of long-term success. The safest path to take is not to think of enablers as separate files. An enableristhe system; when you encounter one on a machine, you're looking at the System file. The traditional methods (INITs, cdevs, components, and so on) are still the only supported ways for developers to extend system functionality.

GIBBLY HISTORY

BY CHRIS DEROSSI
When system enablers were being designed, it was clear they were going to be a mechanism for extending the system. Engineers began calling them INITs, since they served much the same purpose. This caused some confusion with people who thought we really were talking about INITs, and issues were raised about possible conflicts with other INITs, loading order, and so on. (These issues don't apply to system enablers at all.)

It was obvious to me that we needed to change the name to differentiate system enablers from other types of system extension mechanisms. We couldn't use the term extension because that was the public name for INITs. We couldn't use addition because that term already referred to things like QuickDraw GX and AOCE.

So, I decided to use a made-up word. I wanted a word that would be memorable and one that would sound funny when used in all seriousness by executives and upper management. Hence the name "gibblies."

The engineering documentation for gibblies states that the singular is "gibbly" and the plural is "gibblies." It also states that the "g" may be pronounced hard or soft depending on the speaker's preference. In practice, the hard form (as in "give") became the one used by those in the know.

There you have it. And, yes, it was very amusing to hear the made-up word being used all over the company in serious conversation.

K. HAUN works in Apple Developer Technical Support, where he is the perennial winner of the coveted "Most Documentation Heaped on the Floor" award. Before coming to Apple he was a commercial developer, writing educational, game, and utility software on Macintosh, IBM, and Apple II platforms. His main focus in DTS is interapplication communication and application toolbox support. He's also single again; please see ad #298700 in the personal ads section of this issue.

We welcome guest columns from readers who have something interesting or useful to say. Send your column idea or draft to AppleLink DEVELOP or to Caroline Rose at Apple Computer, Inc., 20525 Mariani Avenue, M/S 75-2B, Cupertino, CA 95014.*

Thanks to Chris Derossi, Greg Marriott, and Dean Yu for reviewing this column. *

 
AAPL
$524.94
Apple Inc.
+5.93
MSFT
$40.01
Microsoft Corpora
-0.39
GOOG
$536.10
Google Inc.
-20.44

MacTech Search:
Community Search:

Software Updates via MacUpdate

VMware Fusion 6.0.3 - Run Windows apps a...
VMware Fusion allows you to create a Virtual Machine on your Mac and run Windows (including Windows 8.1) and Windows software on your Mac. Run your favorite Windows applications alongside Mac... Read more
Tweetbot 1.5.1 - Popular iOS twitter cli...
Tweetbot is a full-featured OS X Twitter client with a lot of personality. Whether it's the meticulously-crafted interface, sounds and animation, or features like multiple timelines and column views... Read more
Mac DVDRipper Pro 4.1.7 - Copy, backup,...
Mac DVDRipper Pro is the DVD backup solution that lets you protect your DVDs from scratches, save your batteries by reading your movies from your hard disk, manage your collection with just a few... Read more
PDFpenPro 6.2 - Advanced PDF toolkit for...
PDFpenPro allows users to edit PDF's easily. Add text, images and signatures. Fill out PDF forms. Merge or split PDF documents. Reorder and delete pages. Even correct text and edit graphics! Create... Read more
PDFpen 6.2 - Edit and annotate PDFs with...
PDFpen allows users to easily edit PDF's. Add text, images and signatures. Fill out PDF forms. Merge or split PDF documents. Reorder and delete pages. Even correct text and edit graphics! Features... Read more
Monolingual 1.5.9 - Remove unwanted OS X...
Monolingual is a program for removing unnecesary language resources from OS X, in order to reclaim several hundred megabytes of disk space. It requires a 64-bit capable Intel-based Mac and at least... Read more
Maya 2015 - Professional 3D modeling and...
Maya is an award-winning software and powerful, integrated 3D modeling, animation, visual effects, and rendering solution. Because Maya is based on an open architecture, all your work can be scripted... Read more
Starcraft II: Wings of Liberty 1.1.1.180...
Download the patch by launching the Starcraft II game and downloading it through the Battle.net connection within the app. Starcraft II: Wings of Liberty is a strategy game played in real-time. You... Read more
Sibelius 7.5.0 - Music notation solution...
Sibelius is the world's best-selling music notation software for Mac. It is as intuitive to use as a pen, yet so powerful that it does most things in less than the blink of an eye. The demo includes... Read more
Typinator 5.9 - Speedy and reliable text...
Typinator turbo-charges your typing productivity. Type a little. Typinator does the rest. We've all faced projects that require repetitive typing tasks. With Typinator, you can store commonly used... Read more

Latest Forum Discussions

See All

Have a Special Dead Trigger 2 Easter Bas...
Have a Special Dead Trigger 2 Easter Basket Full of Goodies, Courtesy of Madfinger Games Posted by Rob Rich on April 18th, 2014 [ permalink ] Dead Trigger 2 | Read more »
Almost All of Playdek’s Library is on Sa...
Almost All of Playdek’s Library is on Sale Right Now, and You Should Check it Out Posted by Rob Rich on April 18th, 2014 [ permalink ] Playdek has released quite a few great iOS ports of board and card games over the years, and now most of them... | Read more »
Zynga Launches Brand New Farmville Exper...
Zynga Launches Brand New Farmville Experience with Farmville 2: Country Escape Posted by Tre Lawrence on April 18th, 2014 [ permalink ] | Read more »
David. Review
David. Review By Cata Modorcea on April 18th, 2014 Our Rating: :: MINIMALISTIC IN A DIFFERENT WAYUniversal App - Designed for iPhone and iPad David is a minimalistic game wrapped inside of a soothing atmosphere in which the hero... | Read more »
Eyefi Unveils New Eyefi Cloud Service Th...
Eyefi Unveils New Eyefi Cloud Service That Allows Users to Share Media Across Personal Devices Posted by Tre Lawrence on April 18th, 2014 [ permalink ] | Read more »
Tales from the Dragon Mountain: The Lair...
Tales from the Dragon Mountain: The Lair Review By Jennifer Allen on April 18th, 2014 Our Rating: :: STEADY ADVENTURINGiPad Only App - Designed for the iPad Treading a safe path, Tales from the Dragon Mountain: The Lair is a... | Read more »
Yahoo Updates Flickr App with Advanced E...
Yahoo Updates Flickr App with Advanced Editing Features and More Posted by Tre Lawrence on April 18th, 2014 [ permalink ] | Read more »
My Incredible Body - A Kid's App to...
My Incredible Body - A Kid's App to Learn about the Human Body 1.1.00 Device: iOS Universal Category: Education Price: $2.99, Version: 1.1.00 (iTunes) Description: Wouldn’t it be cool to look inside yourself and see what was going on... | Read more »
Trials Frontier Review
Trials Frontier Review By Carter Dotson on April 18th, 2014 Our Rating: :: A ROUGH LANDINGUniversal App - Designed for iPhone and iPad Trials Frontier finally brings the famed stunt racing franchise to mobile, but how much does its... | Read more »
Evernote Business Notebook by Moleskin I...
Evernote Business Notebook by Moleskin Introduced – Support Available in Evernote for iOS Posted by Tre Lawrence on April 18th, 2014 [ permalink ] | Read more »

Price Scanner via MacPrices.net

Free HopTo 2.2 Helps Enhance Your Productivit...
The HopTo app helps you do more on your iPad by providing more and easier adaccess to files and documents. Version 2.2 adds Egnyte and HopTo’s Mac OSX File Connector. If you already have the hopTo... Read more
National Distracted Driving Awareness Month:...
As the country recognizes National Distracted Driving Awareness Month, Sprint is reminding wireless consumers to focus on driving while behind the wheel, to not text or email while driving, and to... Read more
13-inch 2.4GHz Retina MacBook Pro available f...
Abt has the 13″ 2.4GHz 128GB Retina MacBook Pro available for $1229 including free shipping. Their price is $70 off MSRP. Read more
iMacs on sale for up to $160 off MSRP this we...
Best Buy has iMacs on sale for up to $160 off MSRP for a limited time. Choose free home shipping or free instant local store pickup (if available). Prices are valid for online orders only, in-store... Read more
iPad Airs on sale this weekend for up to $100...
Best Buy has WiFi iPad Airs on sale for $50 off MSRP and WiFi + Cellular iPad Airs on sale for $100 off MSRP on their online store for a limited time, with prices now starting at $449. Choose free... Read more
Apple restocks refurbished Mac minis starting...
The Apple Store has restocked Apple Certified Refurbished Mac minis for up to $150 off the cost of new models. Apple’s one-year warranty is included with each mini, and shipping is free: - 2.5GHz Mac... Read more
Hyundai Brings Apple CarPlay To The 2015 Sona...
Hyundai Motor America has announced it will bring Apple CarPlay functionality to the 2015 Sonata. CarPlay is pitched as a smarter, safer and easier way to use iPhone in the car and gives iPhone users... Read more
Updated iPads Coming Sooner Than We Had Thoug...
MacRumors, cites KGI securities analyst Ming Chi Kuo, well-respected as an Apple product prognisticator, saying that Apple will introduce an upgraded iPad Air and iPad mini in 2014/Q3, meaning the... Read more
Toshiba Unveils New High And Low End Laptop M...
Toshiba has announced new laptop models covering both the high-end and low-end of the notebook computer spectrum. Toshiba 4K Ultra HD Laptop Toshiba’s new Satellite P55t features one of the world’s... Read more
Save up to $270 with Apple refurbished 13-inc...
The Apple Store has Apple Certified Refurbished October 2013 13″ Retina MacBook Pros available starting at $1099, with models up to $270 off MSRP. Apple’s one-year warranty is standard, and shipping... Read more

Jobs Board

*Apple* Automotive Parts Department position...
Apple Automotive is one of the fastest growing dealer…and it shows. Consider making the switch to the Apple Automotive Group today! At Apple Automotive, we Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Retail - Manager - Holyoke - Apple I...
Job Summary Keeping an Apple Store thriving requires a diverse set of leadership skills, and as a Manager, you’re a master of them all. In the store’s fast-paced, Read more
*Apple* Retail - Manager - Apple (United Sta...
Job SummaryKeeping an Apple Store thriving requires a diverse set of leadership skills, and as a Manager, you're a master of them all. In the store's fast-paced, dynamic Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.