TweetFollow Us on Twitter

Function Logging
Volume Number:8
Issue Number:7
Column Tag:C Workshop

Function Logging in Think C

For debugging, optimizing, and better understanding a program’s execution path

By Eric Shapiro, Ann Arbor, Michigan

About the author

Eric Shapiro’s works include Business Simulator®, EzTape®, and two new QuickTime™ programs: Spectator™, a screen recorder from Baseline Publishing and VideoBeep™, a silly Control Panel from Sound Source Unlimited.

Eric has taught Mac programming seminars for Apple and developed the course materials for Apple’s Macintosh Device Driver seminar. He is best known, however, as the author of everyones favorite singing trash can, The Grouch.

Overview

This article presents a simple way to log all function calls into a text file using Think C 5.0. The technique presented here is useful for debugging, optimizing, and obtaining a better understanding of a program’s execution path.

History

In the old days before source level debugging, function logging was an important way to debug Mac programs. On one of my first Mac projects, I remember sending function names out the serial port to a machine running a terminal program in order to figure out where the program was crashing. At MacHack this year, Marshall Clow from Hewlett Packard showed how to log function calls to MacsBug in MPW. Preferring Think C to MPW, I decided that I’d do a similar project for Think C. This article presents the results.

To Use the Logger

If all you want to do is use the function logger, here’s what you need to do:

• Add the file LogToFile.c to your Think C project.

• Add the file ANSI or ANSI-Small to your project (for some string utilities).

• Turn both the profiling and stack frame options on for the project.

• Call LogInit during program initialization (with appropriate parameters).

• Call LogDInit during program de-initialization.

• Recompile your code.

That’s all there is to it! You can control logging more precisely as follows:

• The following line of code turns profiling on for an entire file (if it appears outside of all functions) or for a single routine (if it appears within a function):

/* 1 */
 #pragma options( profile, force_frame )

• Likewise, the following line of code turns profiling off:

/* 2 */
 #pragma options( !profile, !force_frame ) 

• You can determine if logging is active at compile-time using:

/* 3 */
      #if _option( profile )

• Call SetLogState( true ) or SetLogState( false ) to turn logging on or off during program execution. You can do this via a menu selection, for example.

• Call SetLogFlush( true ) or SetLogFlush( false ) to turn flushing on or off during program execution. Performance suffers considerably when flushing is active, but it can help find the location where a crash occurs.

Note: Writing to disk when debugging a program can be a dangerous activity. Be sure you have adequate backups before trying any new debugging technique.

Note: By default, the function logger handles calling depths up to 100 levels. This should be sufficient for all but the most recursive programs. You can change the constant kMaxLogDepth to control the maximum depth.

How The Logger Works

When profiling is active, Think C generates a call to the function _profile_ at the beginning of every function call. Actually, only functions that generate stack frames call _profile_, which is why we turn on the stack frame option as well (stack frames are described below). The _profile_ function has the following form:

/* 4 */
void _profile_( void *functionNamePString )

The first version of _profile_ I wrote simply logged the function name to a file. While this is adequate for some uses, I really wanted to create an indented list of function calls so a programmer can tell exactly who called each function. To do this, our code needs to be notified when a function exits as well as when it is entered. Here’s where life gets a bit complicated.

Unfortunately, Think C’s profiler doesn’t generate a function call whenever a function exits. I looked at Think C’s profiler source code and used a similar technique for my logger. The technique involves replacing return addresses on the stack with the address of our own routine. When a function exits via an rts instruction, it will unknowingly call our exit handler. Our exit handler will decrement a depth counter, write some text to the log file, and jump to the original return address. To understand how we trace back the stack to find return addresses, we need to know exactly how Think C handles stack frames.

Stack Frames

Before and during function execution, space must be allocated for the following items:

• The function’s parameters

• The caller’s return address

• The function’s local variables

• Additional information, such as register contents, that the function may want to store

The first two items, the parameters and return address, are placed on the program stack by the calling code. Space for the the local variables and register storage is also allocated on the stack, but by the function itself. For convenience, the compiler uses register A6 to reference local variables while the stack pointer itself can be lowered and raised during function execution. The previous value of A6 is also placed on the stack so the compiler can easily clean up the stack when a function exits.

If FuncA calls FuncB, and FuncB calls FuncC, the stack looks like that shown in Figure 1.

As you can see, register A6 always points to the start of a linked list of previous A6 values. This is how debuggers such as MacsBug can back-trace function calls (using the SC command). In the _profile_ routine, we need to find the return address of the function that called the function that called us. The assembly language code finds this value on the stack at 4 + the previous A6 value. We save the old return address in a global array before modifying the stack so we know where to return to when our exit handler is called.

Note: If Think C’s force stack frame option is not active, the compiler doesn’t generate a stack frame for functions that have no local variables or parameters. Our _profile_ code is not called for these functions.

Sample Output

The code shown below produces the very simple log file also shown below. Note that the recursion in Func1 works properly. The braces in the output allow you to select an entire function using Think C’s Balance command.

/* 5 */

void DoSomething( void )
{
 Func1();
 Func2( 10 );
}

void Func1( void )
{
 static short  x = 0;
 if ( ++x < 2 )
 Func1();
}

short Func2( short x )
{
 return( 2 * x );
}

Here is the sample output from the code:

/* 6 */

DoSomething
{
 Func1
 {
 Func1 {}
 }
 Func2 {}
}

A simple object-oriented example produces the following output. Note how easy it is to follow the calling sequence of the constructors and destructors for both a base class and a child class.

/* 7 */

DoSomeOopStuff
{
 BaseClass::BaseClass {}
 ChildClass::ChildClass {}
 ChildClass::MiscFunc
 {
 BaseClass::MiscFunc {}
 }
 ChildClass::~ChildClass {}
 BaseClass::~BaseClass {}
}

Summary

A fairly simple technique was given to log function names to a text file for any Think C project, including object-oriented ones. The technique can be used to debug and optimize programs as well as to investigate a program’s runtime activity.

Possible future additions include:

• Put more information into the log file, such as the stack and register contents.

• Make the output look better, perhaps by drawing a graph of the program’s runtime activity.

• Do some validity checking on the heap and file id to make sure that the system is in a reasonably safe state for writing.

• Optionally log information to MacsBug using DebugStr() instead of to the log file.

• Support for interrupt-driven code and trap patches

This would involve setting some semaphores, restoring the global variable context, and changing the I/O calls to be asynchronous. I don’t think it would be very difficult, but as most Mac programmers know, nothing is difficult until you have to implement it.

Good luck, and let me know if you find any bugs.

Listing LogToFile.c
/*
 LogToFile.c
 © 1992 Rock Ridge Enterprises. All Rights Reserved.

 Requires Think C 5.0x

 To use this file:
 1a) Turn on the profiling and stack frame options for your    
 entire project from the Edit/Options/Debugging dialog.
 
 1b) Or, if you prefer, add the following line to your files:
 #pragma options( profile, force_frame )
 Place it within a function to profile just that function,
 within a file for just that file, or in a header file.

 2)Call LogInit at program initialization. For example:
 LogInit( NULL, true, false, true );
 
 3)Call LogDInit at program de-initialization. For example:
 LogDInit();

 4)You can call SetLogState( true ) or SetLogState( false )
 to turn logging on and off dynamically.
*/

#include <string.h>
#include <files.h>
#include <errors.h>
#include <memory.h>
#include <pascal.h>

#include “LogToFile.h”

#define kMaxLogDepth 100  // maximum 100 calls deep

 // create Think C text files as output
#define kThinkCreatorID   ‘KAHL’
#define kTextFileType‘TEXT’

 // strings written to output file
#define kTabString ((void*) “\t” )
#define kReturnString((void*) “\r” )
#define kOpenBraceString  ((void*) “{“)
#define kCloseBraceString ((void*) “}”)
// exiting a function that called nobody
#define kSimpleExitString “ {}”  

 // write this string the top of every log file
#define kStringForNewFile ((void*) “” )

 // write this string between program runs when appending to
 // the log file
#define kStringForReusedFile((void*)
 “\r\r*****************************\r”)

 // the largest buffer we’ll need (+ a little extra)
#define kMaxStringLength  ( kMaxLogDepth + 100 )

 // the default output file is on the root of the boot disk
#define kBootVol -1
#define kRootDir 2L
#define kDefaultPName“\PLog File.txt”

 // don’t profile our profile handler
#pragma options( !profile )

/*
 Permanent storage for this file
*/
static short   gLogFileID = 0;
// vRefNum of log file’s disk
static shortgLogFileVol = -1; 
// true = call FlushVol after every write
static Boolean   gAlwaysFlush = false; 
// true = logging is active
static Boolean   gLogActive = false; 
static FSSpec  gDefaultFileLoc = { kBootVol, kRootDir,
 kDefaultPName };

/*
 Info on the calling chain
*/
// how many calls deep are we?
static long gDepth = 0;   
// the return addresses
static void *gStack[ kMaxLogDepth ]; 
// are braces needed for this function?
static Boolean   gNeedBraces[ kMaxLogDepth ];

/*
 Internal routine prototypes
*/
void    _profile_( void *pFuncName );
void    StringPtoC( void *source, void *target );
OSErr   WriteOpenBrace( short howDeep );
OSErr   WriteFunctionEntry( void *pString );
OSErr   WriteFunctionExit( void );
OSErr   WriteOpenBrace( short howDeep );

/**********************************
 LogInit - Call at program start
 fileLoc- set to NULL or a valid FSSpec for the                
 output file
 deleteOld- true => truncate old log file
 alwaysFlush- true => call FlushVol a lot (better log          
  file if you crash)
 startLogging  - true => turn logging on, false => don’t       
  log yet
**********************************/
OSErr LogInit( FSSpec *fileLoc, Boolean deleteOld,
 Boolean alwaysFlush, Boolean startLogging )
{
 OSErr  err = noErr;
 BooleancreatedFile = false;
 
 if ( !fileLoc )
 // use default if user doesn’t specify one
 fileLoc = &gDefaultFileLoc;

 // in case user calls init twice
 if ( !gLogFileID )
 {
 /*
 Create the file & open the data fork for writing.
 */
 err = FSpCreate( fileLoc, kThinkCreatorID,
 kTextFileType, 0 );
 if ( !err )
 createdFile = true;
 
 err = FSpOpenDF( fileLoc, fsRdWrPerm, &gLogFileID );
 if ( err ) goto DONE;
 }

 /*
 Clear out the file if the user requests it.
 */
 if ( deleteOld )
 {
 err = SetEOF( gLogFileID, 0L );
 if ( err ) goto DONE;
 }

 /*
 Append to the file
 */
 err = SetFPos( gLogFileID, fsFromLEOF, 0 );
 if ( err ) goto DONE;

 /*
 Setup the globals and write ‘****’ to the file.
 */
 gAlwaysFlush = alwaysFlush;
 gLogActive = startLogging;
 gLogFileVol = fileLoc->vRefNum;
 
 // write a header to the file
 if ( deleteOld || createdFile )
 err = WriteLogString( kStringForNewFile );
 else
 err = WriteLogString( kStringForReusedFile );
 
 DONE:
 if ( err )
 LogDInit();

 return( err );
}

/**********************************
 LogDInit - Call at program exit
**********************************/
OSErr LogDInit( void )
{
 OSErr  err;

 if ( !gLogFileID )
 return( openErr );
 
 /*
 Close the file and flush the data to the disk.
 */
 err = FSClose( gLogFileID );
 if ( !err )
 err = FlushVol( NULL, gLogFileVol );
 
 /*
 Clear out the globals so we know we’re not active.
 */
 gLogFileID = 0;
 gLogActive = false;

 return( err );
}

/**********************************
 SetLogState - Call to start or restart logging. 
 Returns previous state.
**********************************/
Boolean SetLogState( Boolean startLogging )
{
 Booleanresult;
 
 result = gLogActive;
 gLogActive = startLogging;

 return( result );
}

/**********************************
 SetLogFlush - Call to start or restart flushing. 
 Returns previous state.
**********************************/
Boolean SetLogFlush( Boolean startFlushing )
{
 Booleanresult;
 
 result = gAlwaysFlush;
 gAlwaysFlush = startFlushing;

 return( result );
}

/**********************************
 ClearLogFile - Call to zero out the log file
**********************************/
OSErr ClearLogFile( void )
{
 OSErr  err = noErr;
 OSErr  err2;
 
 if ( !gLogFileID )
 return( openErr );
 
 err = SetEOF( gLogFileID, 0L );

 if ( gAlwaysFlush )
 {
 err2 = FlushVol( NULL, gLogFileVol );
 if ( !err )
 err = err2;// return the first error to occur
 }

 return( err );
}

/**********************************
 WriteLogString - Write a C string to the log file
**********************************/
OSErr WriteLogString( void *cString )
{
 OSErr  err = noErr;
 OSErr  err2;
 long   numBytes;
 
 if ( !gLogFileID )
 return( openErr );

 /*
 Write the data to the file
 */
 numBytes = strlen( cString );
 err = FSWrite( gLogFileID, &numBytes, cString );
 
 /*
 Flush the volume if we always flush
 */
 if ( gAlwaysFlush )
 {
 err2 = FlushVol( NULL, gLogFileVol );
 if ( !err )
 err = err2;
 }

 return( err );
}

/**********************************
 StringPtoC - Convert a pascal string to a c string
**********************************/
static void StringPtoC( void *source, void *target )
{
 BlockMove( source, target, 1 + *( (unsigned char*)source ));
 PtoCstr( target );
}

/**********************************
 WriteFunctionEntry - called by _profile_ whenever a function  is entered

 The following string is written to the output:
 <CR> + <TABS> + FunctionName
 Where <CR> is a carriage return and <TABS> indicates 1        
 tab per depth.
**********************************/
static OSErr WriteFunctionEntry( void *pString )
{
 Str255 cString;
 unsigned char   theString[ kMaxStringLength ];
 long   count;
 OSErr  err;

 // convert func name to c string
 StringPtoC( pString, cString );   

 // start with a carriage return
 strcpy( (void*)theString, kReturnString );  
 
 // 1 tab for each level
 for ( count=0; count<gDepth; count++ )
 strcat( (void*)theString, kTabString );
 
 // the function name
 strcat( (void*)theString, (void*)cString );

 // write the string
 err = WriteLogString( theString );
 return( err );
}

/**********************************
 WriteFunctionExit - called whenever a function is exited
 by our exit handler

 If this function called another function, write the
 following string:
 <CR> + <TABS> + }
 Otherwise, write:
 {}
 Where <CR> is a carriage return and <TABS> indicates 1
 tab per depth.
**********************************/
static OSErr WriteFunctionExit( void )
{
 OSErr  err = noErr;
 long   count;
 unsigned char   theString[ kMaxStringLength ];
 
 if ( gNeedBraces[ gDepth ] )
 {
 // start with a carriage return
 strcpy( (void*)theString, kReturnString );
 // indent 1 tab for each level
 for ( count=0; count<gDepth; count++ )
 strcat( (void*)theString, kTabString );
 // then a close-brace
 strcat( (void*)theString, kCloseBraceString );
 }
 else
 {
 // just write “exit”
 strcpy( (void*)theString, kSimpleExitString );
 }

// write the string
 err = WriteLogString( theString );
 return( err );
}

/**********************************
 WriteOpenBrace - adds some tabs and an open brace to the
 output

 The following string is written to the output:
 <CR> + <TABS> + {
 Where <CR> is a carriage return and <TABS> indicates 1
 tab per depth.
**********************************/
static OSErr WriteOpenBrace( short howDeep )
{
 OSErr  err;
 unsigned char   theString[ kMaxStringLength ];
 
 // start with a return
 strcpy( (void*)theString, kReturnString );  
 // 1 tab per level deep
 while( howDeep- > 0 )
 strcat( (void*)theString, kTabString );
 // add an open-brace
 strcat( (void*)theString, kOpenBraceString );

 err = WriteLogString( theString );
 return( err );
}

/**********************************
 _profile_ - Called every time a function is entered
 
 This more complicated version does the following:
 1) Prints the function name to the file in
    an indented list
 2) Saves the return address of the caller’s
    caller into gStack[]
 3) Modifies the stack so that the caller returns
    to our code and not to its caller.
 4) Prints exit info when the function is exited and
    then jumps to the correct return address.
**********************************/
void _profile_( void *pFuncName )
{
 OSErr  err;

 if ( !gLogFileID ) return; // output file not opened
 if ( !gLogActive ) return; // logging is off
 if ( gDepth >= kMaxLogDepth ) return; // we’re too deep

 /*
 We have to put an open brace in the output if the parent      
 function hasn’t called any other functions until now.
 */
 if ( gDepth > 0 )
 if ( !gNeedBraces[gDepth-1] )
 {
 gNeedBraces[gDepth-1] = true;
 err = WriteOpenBrace( gDepth-1 );
 if ( err ) return;
 }

 // write the function name
 err = WriteFunctionEntry( pFuncName );
 if ( err ) return;

 gNeedBraces[ gDepth ] = false;
 

 /*
 Save the return address that the caller will return to.
 Modify the stack so that the caller will return to us         
 instead.
 */
 asm
 {
 ; gStack[ gDepth ] = return address where caller
 ; will return to

 ; A1 = &gStack[ gDepth ]
 lea.l  gStack, A1
 move.l gDepth, D0
 lsl.l  #2, D0
 adda.l D0, A1
 
 move.l (A6), A0 ; A0 = A6 from previous call
 move.l 4(A0), (A1); gStack[ gDepth ] = ret Addr
 
 ; Change the return address on the stack to
 ; point to our code
 lea    @FuncExit, A1
 move.l A1, 4(A0)

 addq.l #1, gDepth ; we’re one level deeper now
 
 ; return to caller
 unlk   A6
 rts
 }

 /*
 This code is executed when a profiled function exits
 */
 FuncExit:
 asm
 {
 move.l D0, -(SP); save return value onto stack
 subq.l #1, gDepth ; we’re one level more shallow

 ; write exit info to the file
 jsr    WriteFunctionExit

 ; get the real return address from our array
 ; and jump to it
 
 ; A0 = &gStack[ gDepth ]
 lea.l  gStack, A0
 move.l gDepth, D0
 lsl.l  #2, D0
 adda.l D0, A0
 
 move.l (SP)+, D0; restore return value
 move.l (A0), A0 ; A0=real return address
 jmp    (A0); jump to real return address
 }
}
 

Community Search:
MacTech Search:

Software Updates via MacUpdate

TotalFinder 1.12.2 - Adds tabs, hotkeys,...
TotalFinder is a universally acclaimed navigational companion for your Mac. Enhance your Mac's Finder with features so smart and convenient, you won't believe you ever lived without them. Features... Read more
Duet 2.3.0.3 - Use your iPad as an exter...
Duet is the first app that allows you to use your iDevice as an extra display for your Mac using the Lightning or 30-pin cable. Note: This app requires a $9.99 iOS companion app. Version 2.3.0.3:... Read more
FileMaker Pro Advanced 18.0.3 - Powerful...
FileMaker Pro Advanced is the tool you use to create a custom app. You also use FileMaker Pro Advanced to access your app on a computer. Start by importing data from a spreadsheet or using a built-in... Read more
OsiriX Lite 10.0.6 - 3D medical image pr...
OsiriX Lite is an image processing software dedicated to DICOM images (".dcm" / ".DCM" extension) produced by medical equipment (MRI, CT, PET, PET-CT, ...) and confocal microscopy (LSM and BioRAD-PIC... Read more
Ableton Live 10.1.5 - Record music using...
Ableton Live lets you create and record music on your Mac. Use digital instruments, pre-recorded sounds, and sampled loops to arrange, produce, and perform your music like never before. Ableton Live... Read more
Burn 2.7.8 - Easily burn data, audio, vi...
Burn... There are a lot of ways to approach burning discs. Burn keeps it simple, but still offers a lot of advanced options. Create data discs with advanced data settings like, file permissions, the... Read more
Malwarebytes 4.0.30.3073 - Adware remova...
Malwarebytes (was AdwareMedic) helps you get your Mac experience back. Malwarebytes scans for and removes code that degrades system performance or attacks your system. Making your Mac once again your... Read more
Acorn 6.5.3 - Bitmap image editor.
Acorn is a new image editor built with one goal in mind - simplicity. Fast, easy, and fluid, Acorn provides the options you'll need without any overhead. Acorn feels right, and won't drain your bank... Read more
Fantastical 2.5.13 - Create calendar eve...
Fantastical is the Mac calendar you'll actually enjoy using. Creating an event with Fantastical is quick, easy, and fun: Open Fantastical with a single click or keystroke Type in your event... Read more
A Better Finder Rename 11.05 - File, pho...
A Better Finder Rename is the most complete renaming solution available on the market today. That's why, since 1996, tens of thousands of hobbyists, professionals and businesses depend on A Better... Read more

Latest Forum Discussions

See All

Eternal Warfare is a new idle clicker fo...
Idle games are a popular genre on mobile, they might not be to everyone's taste but they're made with such regularity and receive a lot of downloads, so it's hard to argue it's not big business. Eternal Warfare is set to join the sea of idle games... | Read more »
New heroes and balance updates set to ar...
It feels like Hearthstone: Battlegrounds only launched yesterday, and already the auto batter addition to Blizzard's megahit card game is set to receive new heroes and balance updates. [Read more] | Read more »
Pre-register for Hello Kitty AR: Kawaii...
Hello Kitty — the cute cat that launched a multi-billion-pound franchise — has been brought to life… sort of. Sanrio has teamed up with the Bublar Group to create a new mobile game that uses AR tech to turn the real world into Hello Kitty’s... | Read more »
Gorgeous and tranquil puzzler Spring Fal...
One-man indie studio SPARSE//GameDev has now launched its tranquil puzzler, Spring Falls. It's described as "a peaceful puzzle game about water, erosion, and watching things grow". [Read more] | Read more »
Black Desert Mobile gets an official rel...
Pearl Abyss has just announced that its highly-anticipated MMO, Black Desert Mobile, will launch globally for iOS and Android on December 11th. [Read more] | Read more »
Another Eden receives new a episode, cha...
Another Eden, WFS' popular RPG, has received another update that brings new story content to the game alongside a few new heroes to discover. [Read more] | Read more »
Overdox guide - Tips and tricks for begi...
Overdox is a clever battle royale that changes things up by adding MOBA mechanics and melee combat to the mix. This new hybrid game can be quite a bit to take in at first, so we’ve put together a list of tips to help you get a leg up on the... | Read more »
Roterra Extreme - Great Escape is a pers...
Roterra Extreme – Great Escape has been described by developers Dig-It Games as a mini-sequel to their acclaimed title Roterra: Flip the Fairytale. It continues that game's tradition of messing with which way is up, tasking you with solving... | Read more »
Hearthstone: Battlegrounds open beta lau...
Remember earlier this year when auto battlers were the latest hotness? We had Auto Chess, DOTA Underlords, Chess Rush, and more all gunning for our attention. They all had their own reasons to play, but, at least from where I'm standing, most... | Read more »
The House of Da Vinci 2 gets a new gamep...
The House of Da Vinci launched all the way back in 2017. Now, developer Blue Brain Games is gearing up to deliver a second dose of The Room-inspired puzzling. Some fresh details have now emerged, alongside the game's first official trailer. [Read... | Read more »

Price Scanner via MacPrices.net

B&H offers $100 discounts on 4-Core and 6...
B&H Photo has new 4-Core and 6-Core Mac minis in stock and on sale today for $100 off Apple’s MSRP. Prices start at $699. Overnight shipping is free to many addresses in the US: – 3.6GHz Quad-... Read more
Save $200 today on a 2019 13″ MacBook Air wit...
Apple has a full line of Certified Refurbished 2019 13″ MacBook Airs available starting at only $929 and up to $200 off the cost of new Airs. Each MacBook features a new outer case, comes with a... Read more
New Verizon Pre-Black Friday 2019 deal: Buy o...
Buy one new Apple iPhone 11 model or 2018 iPhone XS model at Verizon and get a second one for free. One new line of service required. Offer is valid from November 21, 2019 to November 27, 2019. Here... Read more
AirPods with Wireless Charging Case on sale t...
Abt Electronics has 2019 AirPods with the Wireless Charging Case on sale today for $163 shipped. Their price is $36 off Apple’s MSRP, and it’s currently the cheapest price for these AirPods from any... Read more
Apple continues to offer 2017 13″ Dual-Core n...
Apple has Certified Refurbished 2017 13″ 2.3GHz Dual-Core non-Touch Bar MacBook Pros still available starting at $1019. An standard Apple one-year warranty is included with each model, outer cases... Read more
Save up to $120 on the new 16″ MacBook Pro at...
Apple’s resellers are starting to receive stock of new 16″ MacBook Pros, and the first set of sales & deals are now available: (1) Amazon 16″ MacBook Pros start on sale for $100-$116 off Apple’s... Read more
Apple Watch Series 3 models on sale at Amazon...
Amazon has Apple Watch Series 3 GPS models on sale for $30 off MSRP, starting at only $169. There prices are the lowest we’ve ever seen for these models from any Apple reseller. Choose Amazon as the... Read more
The ‘Mac Potpourri’ Mailbag: Edition #1- Info...
COMMENTARY: 11.20.19- Welcome to the inaugural edition of the “Mac Potpourri” Mailbag where we take a look at correspondence received from readers of this column from all over the world who write in... Read more
13″ 2.4GHz MacBook Pros available for up to $...
Apple has a full line of Certified Refurbished 2019 13″ 2.4GHz 4-Core Touch Bar MacBook Pros available starting at $1529 and up to $300 off MSRP. Apple’s one-year warranty is included, shipping is... Read more
New at T-Mobile: Switch to T-Mobile, and get...
T-Mobile is offering a free 64GB iPhone 8 for new customers who switch to T-Mobile and open a new line of service. Eligible trade-in required, and discount applied over a 24 month period. The fine... Read more

Jobs Board

Best Buy *Apple* Computing Master - Best Bu...
**747303BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Sales **Store NUmber or Department:** 001413-Cypress-Store **Job Description:** **What Read more
*Apple* Mobility Pro - Best Buy (United Stat...
**743221BR** **Job Title:** Apple Mobility Pro **Job Category:** Store Associates **Store NUmber or Department:** 000230-Greenwood-Store **Job Description:** At Best Read more
*Apple* Mobility Pro - Best Buy (United Stat...
**747338BR** **Job Title:** Apple Mobility Pro **Job Category:** Store Associates **Store NUmber or Department:** 000254-Superstition Springs-Store **Job Read more
Best Buy *Apple* Computing Master - Best Bu...
**745516BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Store Associates **Store NUmber or Department:** 001101-Manhattan-Store **Job Read more
Best Buy *Apple* Computing Master - Best Bu...
**746655BR** **Job Title:** Best Buy Apple Computing Master **Job Category:** Sales **Store NUmber or Department:** 002518-Atlantic Center-Store **Job Description:** Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.