TweetFollow Us on Twitter

Sep 92 Tips
Volume Number:8
Issue Number:5
Column Tag:Tips & Tidbits

Tips & Tidbits

By Neil Ticktin, Editor

This column is your opportunity to spread the word about little bits of information that you find out about. These tidbits can be programming related or they can be user tips that are particularly useful to programmers.

MacTutor will credit, in subscriptions or orders, $25 for every tip used, and $50 for the Tip of the Month. To submit a tip, send in a letter to the magazine.

Remember, AppleLink is our preferred communication method, but feel free to send something via America Online, GEnie or US Mail. If you do send snail mail, enclose a printed copy and a disk copy of the letter so that it does not have to be retyped.

Let us know what you think. Remember, this is your magazine. Try ‘em out and let us know...

Tip of the Month

When you have several applications running at once, and you hit the interrupt button, you will break into the application that happens to be executing at that time, which is not necessarily the one you want to debug.

To choose which application you break into, make sure that application is frontmost. Now hold down the mouse button somewhere over the menu bar (an empty portion will do), and with your other hand, press the interrupt button. You will end up in the desired application, somewhere in the middle of a call to MenuSelect.

Lawrence D’Oliveiro, Computer Services Dept

University of Waikato, Hamilton, New Zealand

MPW MAKE TIP #1

The Make tool in MPW differs from the UNIX original in that it only generates the build commands; it cannot execute them. Apple provides a script called BuildProgram, that invokes Make, captures the output in a temporary script file, and executes it. However, when you’re still at the stage of flushing out syntax errors from your code, it is quicker not to use BuildProgram. Instead, use Make, and capture its output in a temporary window, such as the Worksheet window. Select the generated commands and execute them.

When you hit a syntax error, find the compilation command where the error was encountered, and delete all the commands prior to this-that is, all the commands that were successfully completed. Find and fix the syntax errors in your source file. Now instead of reinvoking BuildProgram or Make, simply reselect the leftover build commands, and reexecute them. Continue in this fashion, deleting the completed commands each time you hit an error, until you’ve completed the build.

If you’ve got nothing else but build commands in the temporary window and you’re using MPW version 3.2 or later, you can quickly select the commands to be deleted, once you’ve found the beginning of the command where the error occurred, by typing command-option-shift-uparrow to select from the current position to the beginning of the file.

- Lawrence D’Oliveiro, New Zealand

MPW MAKE TIP #2

Many Makefiles are written with an initial rule that looks like this:

Everything ƒ Prog1 Prog2 Prog3

where Prog1, Prog2 and so on are the actual programs comprising the project. This is done so that if you invoke Make without any arguments, it will look for the first target by default, and putting this rule first will cause it to build the entire project.

However, if your project grows with more and more components, this becomes another rule that you have to remember to maintain in your Makefile. A more convenient technique is to invoke Make with the following command:

Make `Make -r`

The inner Make -r command returns a list of the “root” targets (that is, no other targets depend on these); the outer Make command builds all these targets. Now you can get rid of the Everything rule, and just keep adding new rules for the new components of your project, without having to worry about updating any existing rules.

- Lawrence D’Oliveiro, New Zealand

MPW BACKUP TIP #1

MPW’s Backup tool is very useful for backing up your projects, but things can get slightly complicated if there are too many files to fit on one disk. Without the -a option, Backup will only back up changed files; it won’t copy any files that aren’t already on the current backup disk.

But if you’ve been adding lots of files to your project, deciding which files should go onto which disks-and making sure you’ve backed them all up-can be too much trouble. You can make things much easier if you group your files into subfolders; just make sure that the contents of each subfolder will fit on one backup disk. Then you can use the command form Backup -a -r -level 1; the -r option means to check subfolders (and subfolders of subfolders, and so on), and -level 1 restricts the effect of -a (backup new as well as changed files) so it only applies to subfolders on down, not to files at the top level. This allows you to keep a handful of central files, such as your Makefile, at the top level, and they will only be backed up once.

If you have to move files from one subfolder to another, add the -d option to the Backup command; this will delete the moved files from their old subfolders on the backup disks.

Now, if Duplicate would only preserve the window positions of the icons it copies, my happiness would be complete...

- Lawrence D’Oliveiro, New Zealand

MPW BACKUP TIP #2

The following pair of commands will do a backup from the current directory onto a folder with the same name on a floppy disk in drive 1:

Set CurFolder "`Directory -q | 
 StreamEdit -d -e 
'/( :)*([¬:]*:)®1 / print ®1'`"

Backup -a -r -level 1 -from 
 : -to `Volumes 1`"{CurFolder}"

This uses the StreamEdit tool which was introduced in MPW 3.2. Put it on a custom menu somewhere in your UserStartup script, then you’ll never have to type it again...

- Lawrence D’Oliveiro, New Zealand

HIDING LAYERS FROM HYPERCARD

The following line of HyperTalk, executed from HyperCard 2.1, will hide the frontmost application:

DoMenu line 1 of menu "Application"

This works even if executed from a script running in the background! You can try other items in the application menu as well, but this doesn’t work for the “System Help” menu.

The same thing should also work from one of your own applications: call SystemMenu, passing it a menu ID of

-16489 (the application menu) and the appropriate item ID (e.g., 1 to hide the frontmost application, 2 to hide all but the frontmost, and 3 to show all applications).

- Lawrence D’Oliveiro, New Zealand

A 68040 Bug

A few months ago a rather large application I wrote started "hanging" on a Quadra 700. After poking around I tracked the problem to a small assembly language routine which is used to allow main thread and interrupt code to access the same linked list of messages.

The problem arises when the CAS2 instruction is used in the following form:

CAS2.l  Dn:Dn,D1:D0,(A0):(A1)

When the comparison fails, Dn gets updated from the second memory operand, (A1), instead of the first memory operand. Motorola has just verified the bug. A portion of Motorola's response, as relayed to me through DTS, says...

"I am responding to your question on the CAS2 instruction. You have indeed found a bug. Your analysis is correct.

If the compare registers for CAS2 are the same and the comparisons with the memory operands fail, then the FIRST memory operand should be stored in the data register, however, the 68040 incorrectly stores the second memory operand in the data register."

Note that this problem does not exist on the 68020 or the 68030.

- Bob Peters, Fermilab

Omega SANE backpatching!

I spent one entire Sunday to catch the bomb in this code:

(1) <if condition then>
(2)   <push a selector on stack>
(3) <else>
(4)   <push another selector on stack>
(5) _FP68K

On the first call Omega SANE analyzes the code and finds that (4) and (5) constitutes a “normal” SANE call. So, in the name of optimization, those 6 bytes are replaced in runtime by a direct JSR to the actual SANE routine. Imagine the spectacular view on a later occasion when (2) and (5) are executed!

- Sigmund Tveit, Norway

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Google Earth 7.1.7.2602 - View and contr...
Google Earth gives you a wealth of imagery and geographic information. Explore destinations like Maui and Paris, or browse content from Wikipedia, National Geographic, and more. Google Earth combines... Read more
ClamXav 2.10 - Virus checker based on Cl...
ClamXav is a popular virus checker for OS X. I have been working on ClamXav for more than 10 years now, and over those years, I have invested a huge amount of my own time and energy into bringing... Read more
Tweetbot 2.4.4 - Popular Twitter client.
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
Sierra Cache Cleaner 11.0.1 - Clear cach...
Sierra Cache Cleaner is an award-winning general purpose tool for macOS X. SCC makes system maintenance simple with an easy point-and-click interface to many macOS X functions. Novice and expert... Read more
Things 2.8.8 - Elegant personal task man...
Things is a task management solution that helps to organize your tasks in an elegant and intuitive way. Things combines powerful features with simplicity through the use of tags and its intelligent... Read more
Remotix 4.1 - Access all your computers...
Remotix is a fast and powerful application to easily access multiple Macs (and PCs) from your own Mac. Features Complete Apple Screen Sharing support - including Mac OS X login, clipboard... Read more
Airfoil 5.1.2 - Send audio from any app...
Airfoil allows you to send any audio to AirPort Express units, Apple TVs, and even other Macs and PCs, all in sync! It's your audio - everywhere. With Airfoil you can take audio from any... Read more
Firefox 49.0.1 - Fast, safe Web browser.
Firefox offers a fast, safe Web browsing experience. Browse quickly, securely, and effortlessly. With its industry-leading features, Firefox is the choice of Web development professionals and casual... Read more
Default Folder X 5.0.7 - Enhances Open a...
Default Folder X attaches a toolbar to the right side of the Open and Save dialogs in any OS X-native application. The toolbar gives you fast access to various folders and commands. You just click on... Read more
Safari Technology Preview 10.1 - The new...
Safari Technology Preview contains the most recent additions and improvements to WebKit and the latest advances in Safari web technologies. And once installed, you will receive notifications of... Read more

4 games like Burly Men at Sea to inspire...
Burly Men at Sea is out today and it looks a treat. It tells the tale of three Scandinavian fishermen who leave the humdrum of their daily lives to go exploring. It’s a beautiful folksy story that unfurls as you interact with the environment... | Read more »
3 reasons you need to play Kingdom: New...
Developed by a tag team of indie developers - Thomas "Noio" van den Berg and Marco "Licorice" Bancale - Kingdom is a vibrant medieval fantasy adventure that casts players as a king or queen who must expand their empire by exploring the vasts lands... | Read more »
JoyCity have launched a brand new King o...
Great news for all of you Game of Dice fans out there - JoyCity have just released a brand new limited edition pack with a really cool twist. The premise of Game of Dice is fairly straightforward, asking you to roll dice to navigate your way around... | Read more »
Burly Men at Sea (Games)
Burly Men at Sea 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: Burly Men at Sea is a folktale about a trio of large, bearded fishermen who step away from the ordinary to seek adventure. | Read more »
3 tips for catching the gnarliest waves...
Like a wave breaking on the shore, Tidal Rider swept its way onto the App Store charts this week settling firmly in the top 10. It’s a one-touch high score-chaser in which you pull surfing stunts while dodging seagulls and collecting coins. The... | Read more »
The beginner's guide to destroying...
Age of Heroes: Conquest is 5th Planet Games’ all new turn-based multiplayer RPG, full of fantasy exploration, guild building, and treasure hunting. It’s pretty user-friendly as far as these games go, but when you really get down to it, you’ll find... | Read more »
Infinite Tanks (Games)
Infinite Tanks 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: | Read more »
Agatha Christie - The ABC Murders (FULL)...
Agatha Christie - The ABC Murders (FULL) 1.0 Device: iOS Universal Category: Games Price: $6.99, Version: 1.0 (iTunes) Description: Agatha Christie: The ABC Murders Your weapon is your knowledge. Your wits will be put to the ultimate... | Read more »
HeadlessD (Games)
HeadlessD 1.0 Device: iOS Universal Category: Games Price: $.99, Version: 1.0 (iTunes) Description: HeadlessD is hand-painted dungeon crawler with intuitive touch controls and NO in-app purchases. | Read more »
Leaf for Twitter (Social Networking)
Leaf for Twitter 1.0.1 Device: iOS iPhone Category: Social Networking Price: $4.99, Version: 1.0.1 (iTunes) Description: | Read more »

Price Scanner via MacPrices.net

Apple refurbished 2015 13-inch MacBook Airs a...
Apple has Certified Refurbished 2015 13″ MacBook Airs available starting at $759. An Apple one-year warranty is included with each MacBook, and shipping is free: - 2015 13″ 1.6GHz/4GB/128GB MacBook... Read more
MacBook Airs on sale for up to $100 off MSRP
B&H Photo has 13″ and 11″ MacBook Airs on sale for up to $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 11″ 1.6GHz/128GB MacBook Air: $799 $100 MSRP - 11″ 1.6GHz/256GB... Read more
Apple refurbished 12-inch 128GB iPad Pros ava...
Apple has Certified Refurbished 12″ Apple iPad Pros available for up to $160 off the cost of new iPads. An Apple one-year warranty is included with each model, and shipping is free: - 32GB 12″ iPad... Read more
Phone2Action Unveils New Voter Turnout Techno...
Phone2Action, a leading digital advocacy platform, today launched its Tech to Vote Civic Action Center digital advocacy and communications platform on National Voter Registration Day September 27.... Read more
Apple & Deloitte Team Up to Help Business...
Apple and international professional services firm Deloitte have announced a partnership to help companies quickly and easily transform their workflow dynamics by maximizing the power, ease-of-use,... Read more
Chop Commute – See Traffic and Drive Times on...
Shrewsbury, Massachusetts based Indie developer, InchWest has released Chop Commute 1.61, a Mac app that takes the guesswork out of daily commute by showing real-time traffic and drive times right on... Read more
12-inch 32GB WiFi iPad Pros on sale for $50 o...
B&H Photo has 12″ 32GB WiFi Apple iPad Pros on sale for $50 off MSRP, each including free shipping. B&H charges sales tax in NY only: - 12″ Space Gray 32GB WiFi iPad Pro: $749 $50 off MSRP -... Read more
Recent price drops on refurbished iPad minis...
Apple recently dropped prices on several Certified Refurbished iPad mini 4s and 2s as well as iPad Air 2s. An Apple one-year warranty is included with each model, and shipping is free: - 16GB iPad... Read more
Apple refurbished Mac minis available startin...
Apple has Certified Refurbished Mac minis available starting at $419. Apple’s one-year warranty is included with each mini, and shipping is free: - 1.4GHz Mac mini: $419 $80 off MSRP - 2.6GHz Mac... Read more
13-inch 2.5GHz MacBook Pro available for $928...
Overstock has the 13″ 2.5GHz MacBook Pro available for $927.99 including free shipping. Their price is $171 off MSRP. Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
Restaurant Manager (Neighborhood Captain) - A...
…in every aspect of daily operation. WHY YOU'LL LIKE IT: You'll be the Big Apple . You'll solve problems. You'll get to show your ability to handle the stress and Read more
*Apple* Wireless Lead - T-ROC - The Retail O...
…wealth of knowledge in wireless sales and activations to the Beautiful and NEW APPLE Experience store within MACYS.. THIS role, APPLE Wireless Lead, isbrandnewas Read more
Lead *Apple* Advocate - T-ROC - The Retail...
…Company, is proud of its unprecedented relationship with our partner and client, APPLE ,in bringing amazing" APPLE ADVOCATES"to "non" Apple store locations. Read more
*Apple* Advocate - T-ROC - The Retail Outsou...
…Company, is proud of its unprecedented relationship with our partner and client, APPLE ,in bringing amazing" APPLE ADVOCATES"to "non" Apple store locations. Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.