TweetFollow Us on Twitter

Nov 93 Tips, Tidbits
Volume Number:9
Issue Number:11
Column Tag:Tips & Tidbits

Tips & Tidbits

By Neil Ticktin, Editor-in-Chief

Tip of the Month

In the September, 1993 issue of MacTech Magazine, one reader wrote in asking about finding out if QuickTime is installed via the Gestalt call. We asked you, the readers, to respond and you a number of you did. Thanks to all of you who responded including: Gary Woodcock, Gary McGath and Mats Hummel who were among the first to respond.

The first answer came from Robert Howe with a nice “clean” answer. The most interesting answer came from Alain Danteny who not only answered this question, but more about Gestalt. Robert and Alain are splitting this month’s prize.

First, the direct answer from Robert Howe: There is a new gestalt selector. You can modify your GestaltEqu.h file (with Think C) to include the following:

/* 1 */

#define gestaltQuickTime 'qtim'

(Realize that this may be included in the new header files that come with the THINK C 6.0.1 update). You may then call it as you would any other gestalt call. If QuickTime is not installed, gestalt returns an error.

A quick boolean check could be written as

/* 2 */

#include <GestaltEqu.h>
 
if (QuickTimeInstalled());
     // play a movie
 

Boolean QuickTimeInstalled ( void ) {
     return (noErr == gestalt('qtim', &result)); 
}

- Robert Howe,

via America Online

More Gestalt information

Next, comes the additional information from Alain Danteny. If you want to have a full view of all currently installed and registered gestaltSelectors, follow these steps: First, call Gestalt with selector "tabl". The response (a pointer) is the starting address of an array containing all the gestaltSelector and procAddress. The format of each entry is:

{ 3 }

gestaltTableEntry = RECORD
      gestaltSelector : OSType;
      gestaltAddr : LongInt;
    END; {Pascal-like}

/* 4 */

struct{
    OSType gestaltSelector;
    long gestaltAddr;
}gestaltTableEntry;//C-like

The very first 2 entries are:

0000 000C xxxx xxxx ; (selector = $0000 000C in hexa)
0000 0007 yyyy yyyy ;

Those are undoubtly the selectors of Gestalt's developers at Apple: Carl C. Hewitt and <unknown?>. Moreover, under macsbug, if you type:

ip xxxx xxxx (see above)

you will decompile the gestaltProc and see that those selectors are probably used internaly by the traps Gestalt, NewGestalt, ReplaceGestalt... the gestaltProc uses two signatures: "carl" and "bbmc" (who's bbmc?)

Following entries are non-Apple gestaltSelectors: mainly INITS and cdev signatures (ADex, ADrk, MClk, NowT aso). Last are well-known Apple's system Selectors. This array ends up with longint $7FFF FFFF.

- Alain Danteny,

Nancy, France

MOVEM.L Warning!

The MOVEM is a 680x0 assembler instruction. It is used a lot for saving and restoring the values of multiple data and address registers. I tried to save off two address register values with the lower register first and then restoring it later using two MOVE.L instructions. I ran into an unexpected surprise. The instruction:

MOVEM.L A2/A4,-(A7)

is not equivalent as you would expect to the 2 instructions:

MOVE.L  A2,-(A7)
MOVE.L  A4,-(A7)

but instead to:

MOVE.L  A4,-(A7)
MOVE.L  A2,-(A7)

The instruction MOVEM.L stores the registers from high to low, ignoring the order you specify. In other words,

MOVEM.L A2/A4,-(A7)

does the same thing as:

MOVEM.L A4/A2,-(A7)

Using MOVEM pre-decriment, -(A7), in conjunction with MOVEM postincrement, (A7)+, addressing, saving off and restoring the same registers is what the instruction was apparently designed for and works just fine for that purpose.

- Marek Hajek

Hajek’s Solutions

Reno, Nevada

Toggle invisibles in MPW

I often need to see “invisible” characters in text files, because many of mine come from BBS captures and may have glitches in them. MPW’s sequence for turning the display of invisible characters on and off is cumbersome, so I added a menu and keyboard shortcut; a single command to toggle the display. The following command adds a “Toggle Invisibles” to the Edit menu, so Command-Option-Y (displayed as ¥, option-Y) does the trick.

/* 5 */

AddMenu Edit "Toggle Invisibles/¥" 
 'If `Format -x a "{Active}"` == "Ail" ; 
   Format -a AIl "{Active}" ; 
  Else ; 
   Format -a Ail "{Active}" ; 
  End'

What this does: The first Format command, `Format -x a "{Active}"`, emits a string describing the active window’s format attributes. The If statement compares this to a default string of “Ail”: “A” for Auto-indent on, “i” for invisibles off, and “l” for lock-scroll off. Based on the result of that comparison, another Format command is issued to turn the display of invisible characters on or off (Format -a AIl or Format -ia Ail, respectively).

The format attribute strings “Ail” and “AIl” assume the other defaults for the file format attributes are Auto-indent ON and lock-scroll OFF. These are the common defaults, but you can change them by switching the case of the A and L in the format command. For example, if you prefer to not auto-indent, the format attribute strings would be “ail” and “aIl” instead.

- Lee David Rimar

Absoft Corporation

Need information on your Macintosh?

Need some extensive information about your Mac? In AppleLink, press Option - Command - D.

- William Modesitt

Maui Software

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Ellipsis - Touch. Explore. Survive. (...
Ellipsis - Touch. Explore. Survive. 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: | Read more »
Ys Chronicles II (Games)
Ys Chronicles II 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: After a hard fight to recover the six sacred books in Ys Chronicles I, Adol is back for a sequel! | Read more »
FINAL FANTASY Ⅸ (Games)
FINAL FANTASY Ⅸ 1.0.4 Device: iOS Universal Category: Games Price: $16.99, Version: 1.0.4 (iTunes) Description: ==========●Special sale price for the FINAL FANTASY IX release! ●20% off from February 10 to February 21, 2016... | Read more »
Tennis Club Story (Games)
Tennis Club Story 1.03 Device: iOS Universal Category: Games Price: $4.99, Version: 1.03 (iTunes) Description: Aim for the ace position of tennis club prestige in this simulation! Your leadership decides if players make it to the big... | Read more »
Juggernaut Wars guide - How to use skill...
Juggernaut Warsis a brand new auto-RPG on iOS and Android that challenges you to build a team of heroes, send them out into various different missions to defeat waves of heroes, and level them up to increase their power. The actual combat itself... | Read more »
Check out the new Pirate Attack update i...
Love pirates and board games? Well, you'll love the new Pirate Attack themed update that just launched in Game of Dice. It adds a bunch of new content themed around pirates, like an all new event map based on a pirate ship which revamps the toll... | Read more »
Splash Cars guide - How to paint the tow...
Splash Cars is an arcade driving game that feels like a hybrid between Dawn of the Plow and Splatoon. In it, you'll need to drive a car around to repaint areas of a town that have lost all of their color. Check out these tips to help you perform... | Read more »
The best video player on mobile
We all know the stock video player on iOS is not particularly convenient, primarily because it asks us to hook a device up to iTunes to sync video in a world that has things like Netflix. [Read more] | Read more »
Four apps to help improve your Super Bow...
Super Bowl Sunday is upon us, and whether you’re a Panthers or a Broncos fan you’re no doubt gearing up for it. [Read more] | Read more »
LooperSonic (Music)
LooperSonic 1.0 Device: iOS Universal Category: Music Price: $4.99, Version: 1.0 (iTunes) Description: LooperSonic is a multi-track audio looper and recorder that will take your loops to the next level. Use it like a loop pedal to... | Read more »

Price Scanner via MacPrices.net

App Annie Reveals Future of the App Economy:...
App Annie, a San Francisco based mobile app data and insights platform, has launched its first comprehensive app economy forecast. This new offering will provide brands, agencies, investors and app... Read more
Apple restocks Certified Refurbished Mac mini...
Apple has restocked Certified Refurbished 2014 Mac minis, with models available starting at $419. Apple’s one-year warranty is included with each mini, and shipping is free: - 1.4GHz Mac mini: $419 $... Read more
What iPad Pro Still Needs To Make It Truly Pr...
I love my iPad Air 2. So much that I’m grudgingly willing to put up with its compromises and limitations as a production tool in order to take advantage of its virtues. However, since a computer for... Read more
21-inch 3.1GHz 4K on sale for $1399, $100 off...
B&H Photo has the 21″ 3.1GHz 4K iMac on sale $1399 for a limited time. Shipping is free, and B&H charges NY sales tax only. Their price is $100 off MSRP: - 21″ 3.1GHz 4K iMac (MK452LL/A): $... Read more
Apple price trackers, updated continuously
Scan our Apple Price Trackers for the latest information on sales, bundles, and availability on systems from Apple’s authorized internet/catalog resellers. We update the trackers continuously: - 15″... Read more
Save up to $240 with Apple Certified Refurbis...
Apple is now offering Certified Refurbished 12″ Retina MacBooks for up to $240 off the cost of new models. Apple will include a standard one-year warranty with each MacBook, and shipping is free. The... Read more
Apple refurbished 13-inch Retina MacBook Pros...
Apple has Certified Refurbished 13″ Retina MacBook Pros available for up to $270 off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free: - 13″ 2.7GHz... Read more
Apple refurbished Time Capsules available for...
Apple has certified refurbished Time Capsules available for $120 off MSRP. Apple’s one-year warranty is included with each Time Capsule, and shipping is free: - 2TB Time Capsule: $179, $120 off - 3TB... Read more
13-inch 2.5GHz MacBook Pro (refurbished) avai...
Apple has Certified Refurbished 13″ 2.5GHz MacBook Pros available for $829, or $270 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.5GHz MacBook Pros... Read more
Apple refurbished 15-inch Retina MacBook Pros...
Apple has Certified Refurbished 2015 15″ Retina MacBook Pros available for up to $380 off the cost of new models. An Apple one-year warranty is included with each model, and shipping is free: - 15″ 2... Read more

Jobs Board

Lead Engineer - *Apple* OSX & Hardware...
Lead Engineer - Apple OSX & Hardware **Job ID:** 3125919 **Full/Part\-Time:** Full\-time **Regular/Temporary:** Regular **Listed:** 2016\-02\-10 **Location:** Cary, Read more
Simply Mac *Apple* Specialist- Service Repa...
Simply Mac is the largest premier retailer of Apple products in the nation. In order to support our growing customer base, we are currently looking for a driven Read more
Infrastructure Engineer - *Apple* /Mac - Rem...
…part of a team Requires proven problem solving skills Preferred Additional: Apple Certified System Administrator (ACSA) Apple Certified Technical Coordinator (ACTC) Read more
Lead Engineer - *Apple* OSX & Hardware...
Lead Engineer - Apple OSX & Hardware **Job ID:** 3125919 **Full/Part\-Time:** Full\-time **Regular/Temporary:** Regular **Listed:** 2016\-02\-10 **Location:** Cary, Read more
*Apple* System Analyst - ATOS IT Services...
Apple System AnalystReference no.198783CountryUSARegionUS - CALIFORNIACityUS - CALIFORNIA - BURBANKPosition TypeProfessionalJob AreaIT SupportJob TypeFull Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.