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
$104.83
Apple Inc.
+1.84
MSFT
$45.02
Microsoft Corpora
+0.64
GOOG
$543.98
Google Inc.
+11.27

MacTech Search:
Community Search:

Software Updates via MacUpdate

Delicious Library 3.3.2 - Import, browse...
Delicious Library allows you to import, browse, and share all your books, movies, music, and video games with Delicious Library. Run your very own library from your home or office using our... Read more
Art Text 2.4.8 - Create high quality hea...
Art Text is an OS X application for creating high quality textual graphics, headings, logos, icons, Web site elements, and buttons. Thanks to multi-layer support, creating complex graphics is no... Read more
Live Interior 3D Pro 2.9.6 - Powerful an...
Live Interior 3D Pro is a powerful yet very intuitive interior designing application. View Video Tutorials It has every feature of Live Interior 3D Standard, plus some exclusive ones: Create multi... Read more
The Hit List 1.1.7 - Advanced reminder a...
The Hit List manages the daily chaos of your modern life. It's easy to learn - it's as easy as making lists. And it's powerful enough to let you plan, then forget, then act when the time is right.... Read more
jAlbum Pro 12.2.4 - Organize your digita...
jAlbum Pro has all the features you love in jAlbum, but comes with a commercial license. With jAlbum, you can create gorgeous custom photo galleries for the Web without writing a line of code!... Read more
jAlbum 12.2.4 - Create custom photo gall...
With jAlbum, you can create gorgeous custom photo galleries for the Web without writing a line of code! Beginner-friendly, with pro results Simply drag and drop photos into groups, choose a design... Read more
ExpanDrive 4.1.7 - Access remote files o...
ExpanDrive builds cloud storage in every application, acts just like a USB drive plugged into your Mac. With ExpanDrive, you can securely access any remote file server directly from the Finder or... Read more
OmniOutliner Pro 4.1.3 - Pro version of...
OmniOutliner Pro is a flexible program for creating, collecting, and organizing information. Give your creativity a kick start by using an application that's actually designed to help you think. It'... Read more
Evernote 5.6.2 - Create searchable notes...
Evernote allows you to easily capture information in any environment using whatever device or platform you find most convenient, and makes this information accessible and searchable at anytime, from... Read more
OmniOutliner 4.1.3 - Organize your ideas...
OmniOutliner is a flexible program for creating, collecting, and organizing information. Give your creativity a kick start by using an application that's actually designed to help you think. It's... Read more

Latest Forum Discussions

See All

Toca Boo (Education)
Toca Boo 1.0.2 Device: iOS Universal Category: Education Price: $2.99, Version: 1.0.2 (iTunes) Description: BOO! Did I scare you!? My name is Bonnie and my family loves to spook! Do you want to scare them back? Follow me and I'll... | Read more »
Intuon (Games)
Intuon 1.1 Device: iOS Universal Category: Games Price: $.99, Version: 1.1 (iTunes) Description: Join the battle with your intuition in a new hardcore game Intuon! How well do you trust your intuition? Can you find a needle in a... | Read more »
Ravenous Rampage (Games)
Ravenous Rampage 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: | Read more »
Partia 2 (Games)
Partia 2 1.0.1 Device: iOS Universal Category: Games Price: $5.99, Version: 1.0.1 (iTunes) Description: Partia 2 is a SRPG (Strategy Role-playing) video game inspired by Fire Emblem and Tear Ring Saga series. In a high fantasy... | Read more »
Puzzle to the Center of the Earth Review
Puzzle to the Center of the Earth Review By Campbell Bird on October 23rd, 2014 Our Rating: :: SPELUNKING PUZZLESUniversal App - Designed for iPhone and iPad Do some puzzles to make some platforms in this smart and fun free-to-play... | Read more »
Sleep Attack TD Review
Sleep Attack TD Review By Jennifer Allen on October 23rd, 2014 Our Rating: :: A TRUE TWISTUniversal App - Designed for iPhone and iPad Sleep Attack TD is a tower defense game with a difference – you can rotate the layout – and it’s... | Read more »
Mecanic (Education)
Mecanic 1.0 Device: iOS Universal Category: Education Price: $1.99, Version: 1.0 (iTunes) Description: Plates, screws, wheels ... Everything you need to achieve whatever you want... MECHANICWith 'MECANIC' kids will have fun... | Read more »
Earn Your Master Camper Badge in Camp Po...
Earn Your Master Camper Badge in Camp Pokemon Posted by Jessica Fisher on October 23rd, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Garruk Gets His Revenge in a New Magic 2...
Garruk Gets His Revenge in a New Magic 2015 Expansion, Coming This November Posted by Jessica Fisher on October 23rd, 2014 [ permalink ] | Read more »
Sentinels of the Multiverse Review
Sentinels of the Multiverse Review By Rob Thomas on October 23rd, 2014 Our Rating: :: SENTINELS ASSEMBLEiPad Only App - Designed for the iPad Greater Than Games’ tabletop classic, Sentinels of the Multiverse swoops in to save the... | Read more »

Price Scanner via MacPrices.net

Save up to $125 on Retina MacBook Pros
B&H Photo has the new 2014 13″ and 15″ Retina MacBook Pros on sale for up to $125 off MSRP. Shipping is free, and B&H charges NY sales tax only. They’ll also include free copies of Parallels... Read more
Apple refurbished Time Capsules available sta...
The Apple Store has certified refurbished Time Capsules available for up to $60 off MSRP. Apple’s one-year warranty is included with each Time Capsule, and shipping is free: - 2TB Time Capsule: $255... Read more
Textilus New Word, Notes and PDF Processor fo...
Textilus is new word-crunching, notes, and PDF processor designed exclusively for the iPad. I haven’t had time to thoroughly check it out yet, but it looks great and early reviews are positive.... Read more
WD My Passport Pro Bus-Powered Thunderbolt RA...
WD’s My Passport Pro RAID solution is powered by an integrated Thunderbolt cable for true portability and speeds as high as 233 MB/s. HighlightsOverviewSpecifications Transfer, Back Up And Edit In... Read more
Save with Best Buy’s College Student Deals
Take an additional $50 off all MacBooks and iMacs at Best Buy Online with their College Students Deals Savings, valid through November 1st. Anyone with a valid .EDU email address can take advantage... Read more
iPad Air 2 & iPad mini 3 Best Tablets Yet...
The new iPads turned out to be pretty much everything I’d been hoping for and more than I’d expected.”More” particularly in terms of a drinking-from-a-firehose choice of models and configurations,... Read more
Drafts 4 Reinvents iOS Productivity App
N Richland Hills, Texas based Agile Tortoise has announced the release of Drafts 4 for iPhone and iPad. Drafts is a quick capture note taking app with flexible output actions. Drafts 4 scales from... Read more
AT&T accepting preorders for new iPads fo...
AT&T Wireless is accepting preorders for the new iPad Air 2 and iPad mini 3, cellular models, for $100 off MSRP with a 2-year service agreement: - 16GB iPad Air 2 WiFi + Cellular: $529.99 - 64GB... Read more
Apple offering refurbished Mac Pros for up to...
The Apple Store is offering Apple Certified Refurbished 2013 Mac Pros for up to $600 off the cost of new models. An Apple one-year warranty is included with each Mac Pro, and shipping is free. The... Read more
Select MacBook Airs $100 off MSRP, free shipp...
B&H Photo has 2014 a couple of MacBook Airs on sale for $100 off MSRP. Shipping is free, and B&H charges NY sales tax only. They also include free copies of Parallels Desktop and LoJack for... Read more

Jobs Board

Senior Event Manager, *Apple* Retail Market...
…This senior level position is responsible for leading and imagining the Apple Retail Team's global event strategy. Delivering an overarching brand story; in-store, 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
Project Manager / Business Analyst, WW *Appl...
…a senior project manager / business analyst to work within our Worldwide Apple Fulfillment Operations and the Business Process Re-engineering team. This role will work Read more
*Apple* Retail - Multiple Positions (US) - A...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Position Opening at *Apple* - Apple (United...
…customers purchase our products, you're the one who helps them get more out of their new Apple technology. Your day in the Apple Store is filled with a range of Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.