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

ExpanDrive 6.1.8 - Access cloud storage...
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
DiskCatalogMaker 7.2.7 - Catalog your di...
DiskCatalogMaker is a simple disk management tool which catalogs disks. Simple, light-weight, and fast Finder-like intuitive look and feel Super-fast search algorithm Can compress catalog data for... Read more
DiskCatalogMaker 7.2.7 - Catalog your di...
DiskCatalogMaker is a simple disk management tool which catalogs disks. Simple, light-weight, and fast Finder-like intuitive look and feel Super-fast search algorithm Can compress catalog data for... Read more
Iridient Developer 3.2.1 - Powerful imag...
Iridient Developer (was RAW Developer) is a powerful image-conversion application designed specifically for OS X. Iridient Developer gives advanced photographers total control over every aspect of... Read more
BusyContacts 1.2.7 - Fast, efficient con...
BusyContacts is a contact manager for OS X that makes creating, finding, and managing contacts faster and more efficient. It brings to contact management the same power, flexibility, and sharing... Read more
MegaSeg 6.0.5 - Professional DJ and radi...
MegaSeg is a complete solution for pro audio/video DJ mixing, radio automation, and music scheduling with rock-solid performance and an easy-to-use design. Mix with visual waveforms and Magic... Read more
BusyContacts 1.2.7 - Fast, efficient con...
BusyContacts is a contact manager for OS X that makes creating, finding, and managing contacts faster and more efficient. It brings to contact management the same power, flexibility, and sharing... Read more
MegaSeg 6.0.5 - Professional DJ and radi...
MegaSeg is a complete solution for pro audio/video DJ mixing, radio automation, and music scheduling with rock-solid performance and an easy-to-use design. Mix with visual waveforms and Magic... Read more
Iridient Developer 3.2.1 - Powerful imag...
Iridient Developer (was RAW Developer) is a powerful image-conversion application designed specifically for OS X. Iridient Developer gives advanced photographers total control over every aspect of... Read more
iFFmpeg 6.6.1 - Convert multimedia files...
iFFmpeg is a comprehensive media tool to convert movie, audio and media files between formats. The FFmpeg command line instructions can be very hard to master/understand, so iFFmpeg does all the hard... Read more

Latest Forum Discussions

See All

The best deals on the App Store this wee...
A new week means new discounts on the App Store. This week's deals run the gamut of action-adventure titles, puzzle games, and one of the best narrative adventure series out there. If you're looking to fill out your mobile gaming library on a... | Read more »
What you need to know about Animal Cross...
We hope you've been hard at work on collecting all of those holiday items in Animal Crossing: Pocket Camp, because you're about to get a whole new list of fun things to do as the game receives its first big update sometime soon. There are a lot of... | Read more »
Reigns: Her Majesty guide - how to use e...
Ruling a kingdom isn't easy--doubly so for a queen whose every decision is questioned by the other factions seeking a slice of power. Reigns: Her Majesty builds on the original game's swipey tactics, adding items that you can use to move the story... | Read more »
The best new games we played this week -...
Friday has crept up on us once again, so it's time to honor the best new games we've played over the past few days. This past week was a pretty exciting one, with the debut of lots of beautiful new indies and some familiar faces returning to the... | Read more »
Portal Knights guide- beginner tips and...
Portal Knights is finally making the jump to iOS and Android, and it's already climbing the ranks to become the next big MMO experience on mobile. This sprawling sandbox game will let you pursue any adventure you wish, whether you want to sling... | Read more »
Reigns: Her Majesty guide - how to swipe...
Reigns: Her Majesty is storming the App Store this week, bringing more tinder-esque kingdom building to eager players everywhere. If you've played the original Reigns, you'll know that leading a kingdom is never easy. It's a careful balancing act... | Read more »
Getting Over It (Games)
Getting Over It 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: A game I madeFor a certain kind of person To hurt them. • Climb up an enormous mountain with nothing but a hammer and a pot.•... | Read more »
Reigns: Her Majesty (Games)
Reigns: Her Majesty 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: | Read more »
Pocket Legends Adventures guide - how to...
Pocket Legends Adventures is a fun action adventure RPG that takes control when you want it to, but also opens itself for player input, too, if you're looking to tkae a more active role in combat. Regardless of play style, the game can be quite... | Read more »
Portal Knights (Games)
Portal Knights 1.2.4 Device: iOS Universal Category: Games Price: $4.99, Version: 1.2.4 (iTunes) Description: Craft your adventure. Forge your hero. Become the ultimate Portal Knight! | Read more »

Price Scanner via MacPrices.net

Green Monday deal: 15″ 2.8GHz MacBook Pro on...
B&H Photo has the 15″ 2.8GHz Space Gray MacBook Pro on sale for $250 off MSRP for today only as part of their Green Monday/Holiday sale. Shipping is free, and B&H charges sales tax for NY... Read more
Green Monday sale: B&H offers 12″ Apple i...
B&H Photo has 12″ iPad Pros on sale for up to $150 off MSRP as part of their Green Monday/Holiday sale. Shipping is free, and B&H charges sales tax in NY & NJ only: – 12″ 64GB WiFi iPad... Read more
Holiday deal: 21″ and 27″ Apple iMacs on sale...
MacMall has 2017 21″ and 27″ Apple iMacs on sale for up to $200 off MSRP. Shipping is free: – 21″ 2.3GHz iMac: $999 $100 off MSRP – 21″ 3.0GHz iMac: $1199 $100 off MSRP – 21″ 3.4GHz iMac: $1379 $120... Read more
Holiday deal: Apple Mac minis for up to $150...
MacMall has Mac minis on sale for up to $100 off MSRP, each including free shipping: – 1.4GHz Mac mini: $399 $100 off MSRP – 2.6GHz Mac mini: $599 $100 off MSRP – 2.8GHz Mac mini: $949 $50 off MSRP... Read more
Beats by Dr. Dre – BeatsX Earphones on sale f...
Best Buy has BeatsX Earphones on sale for $109, $40 off, on their online store. Sale price for online orders only. Choose free store pickup, if available, or choose free shipping. Read more
10″ 64GB WiFi Apple iPad Pros on sale for $59...
MacMall has 10.5″ 64GB Apple iPad Pros on sale for $599 including free shipping. That’s $50 off MSRP and among the lowest prices available for these iPads from any Apple reseller. Read more
15″ 2.2GHz MacBook Pros on sale for $200-$300...
B&H Photo has the 15″ 2.2GHz MacBook Pro available for $200 off MSRP including free shipping plus NY & NJ sales tax only: – 15″ 2.2GHz MacBook Pro (MJLQ2LL/A): $1799 $200 off MSRP Apple has... Read more
Holiday sale: 15″ MacBook Pros for $200-$420...
MacMall has 15″ MacBook Pros on sale for $220-$300 off MSRP, each including free shipping: – 15″ 2.8GHz MacBook Pro Space Gray (MPTR2LL/A): $2179, $220 off MSRP – 15″ 2.8GHz MacBook Pro Silver (... Read more
Holiday sale: 13″ MacBook Airs for up to $150...
B&H Photo has 13″ MacBook Airs on sale for $100 off MSRP as part of their Holiday sale. Shipping is free, and B&H charges sales tax for NY & NJ residents only: – 13″ 1.8GHz/128GB MacBook... Read more
The best Holiday sale prices on 13″ MacBook P...
B&H Photo has 13″ MacBook Pros on sale this weekend, with models available for $100-$150 off MSRP. Shipping is free, and B&H charges sales tax for NY & NJ residents only: – 13-inch 2.3GHz... Read more

Jobs Board

*Apple* Retail - Multiple Positions - Apple,...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Information Security - Security Data...
# Apple Information Security - Security Data Analyst Job Number: 113119545 Austin, Texas, United States Posted: 10-Nov-2017 Weekly Hours: 40.00 **Job Summary** This Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.