TweetFollow Us on Twitter





[IMAGE 123-125_Puzzle_Page_rev1.GIF]

See if you can solve this programming puzzle, presented in the form of a dialog between Konstantin Othmer (KON) and Bruce Leak (BAL). The dialog gives clues to help you. Keep guessing until you're done; your score is the number to the left of the clue that gave you the correct answer. These problems are supposed to be tough. If you don't get a high score, at least you'll learn interesting Macintosh trivia.

100 BAL This guy has this program that leaves all the palette colors messed up after his program quits.

KON Yeah, I've seen it. He's probably got version 1.0 of that KeithPaint program.

90 BAL This is something he wrote with MPW C, and he spent days debugging his code with SADE. He's sure it's not his problem.

KON Sounds like some kind of Palette Manager nastiness.

80 BAL He sends you a copy and it works fine on your machine.

KON Which system is he running? How many monitors does he have?

75 BAL You're both running 6.0.7 on a Macintosh fx with one Apple 13-inch color monitor.

KON That's a nice programming environment. Why doesn't he upgrade to System 7 and buy himself a real monitor?

70 BAL Well, he has System 7 on a Macintosh Quadra with a 16-inch color monitor for reading NetNews and watching QuickTime movies. But the bug doesn't happen on that machine.

KON So it must be some INIT conflict. What's he got, ColorDesk or something?

65 BAL Nope, happens without any INITs.

KON He's using the Color Manager and calling some nasty thing like SaveEntries or RestoreEntries, and he isn't MultiFinder compatible. I tell him to use the Palette Manager.

60 BAL He's using the Palette Manager, and he's totally MultiFinder friendly.

KON Sounds impossible. I swap motherboards with him.

55 BAL Still happens, just on his machine. If you swapped hard drives it would happen on yours.

KON It's got to be some kind of GDevice color table thing. I check the GDevice color table before and after running his program.

BAL Wait a second. Who has which hard drive?

KON I have mine, he has his.

50 BAL The color tables are different on his GDevice, but the same on yours.

KON Well, who restores the color table? PaletteMgrExit or something like that, right?

45 BAL The Palette Manager changes the color environment only when a window with an associated palette comes to the front. This method assumes that people who need colors request them, and people who don't request colors don't care enough to affect the color environment. Unfortunately, with this approach to color management, when an application that's Palette Manager intensive quits, and an application such as the Finder which has no intensive color demands comes to the front, you're stuck with the nonstandard color state of the application that just quit. In 32-Bit QuickDraw David Van Brink extended the Palette Manager to include a routine called PaletteMgrExit. This routine is called automatically for you when your application quits, thus restoring the default color state.

KON Don't you have the same problem when twitching between layers? If you twitch to the Finder and the other application is still running, you'll be stuck with the nonstandard color state too.

40 BAL Yeah, but there's still an application around that needs those colors, and you can potentially see that application's documents, so it's a good bet to keep them. No one is specifically asking for the standard colors, and someone wants the others, so why not keep them around? If you twitch to another application that had palettes, obviously its color needs will be satisfied.

KON So in effect you start out with a default color world, and you launch an application that twists the colors to the demands of a particular document you're viewing or editing. Upon quitting that application your machine is left in some nonstandard color state. So PaletteMgrExit cleans up the mess.

35 BAL That's basically it, but just going back to the default color environment when an application quits isn't sufficient. PaletteMgrExit reverts to the default color set modified to accommodate the application coming to the front.

KON I set an ATB on PaletteMgrExit and see if it gets called.

30 BAL It's called on your machine, but not his.

KON Well, ExitToShell is supposed to call it, and it's hard to call ExitToShell wrong, so there must be some system problem.

25 BAL Welcome to the Puzzle Page, KON. Maybe this would be an excellent opportunity to fire up one of those many fine Macintosh debugging environments, Mr. MacsBug.

KON Clearly _ExitToShell is different. So I list ExitToShell with MacsBug and see who's there.

20 BAL It's in RAM.

KON I see whose heap it's in using HZ.

15 BAL It's above all heaps.

KON So it's in MultiFinder memory. He must be running an old version of MultiFinder that doesn't know about PMgrExit.

10 BAL Yeah, you know that SetAside MultiFinder they still ship with SADE?

KON Version 6.1b9. Sounds like they never really finished it.

5 BAL Well, my hero Phil Goldman broke off the sources to add that SetAside stuff, but it was never shipped as an official Apple release, since System 7 was just around the corner. SADE needed that feature because they twitch in some weird way. So they're sort of stuck using that version, while the rest of the world moves on. And they keep shipping that old MultiFinder for those last two, die-hard, System 6 developers. System 7 SADE users don't have this problem.

KON Nasty.

BAL Yeah.

KONSTANTIN OTHMER AND BRUCE LEAKBetween vacations, KON and BAL often find themselves under a lot of pressure to catch up on their work load. When BAL gets himself in too deep, he calls

KON in for assistance. They try to hash out their puzzling problems at Apple's Fitness Center---although

KON admits to having trouble staying focused, due to what we can only call his "wandering eye." When not working on Puzzle Pages and develop  articles,

KON and

BAL actually write software. As a follow-on to their previous QuickDraw and QuickTime successes, look for QuickFit, featuring QuickTime-based exercise videos and QuickBuf protein powder. You read it here first! *


  • 90-100 So you're still using System 6 with SADE? Upgrade to System 7 immediately!
  • 60-80 Do you swear to tell the truth, the whole truth, and nothing but the truth?
  • 35-55 Good job. Next time you're in L.A., try out for "Jeopardy."
  • 5-30 Hey, we're with you! MacsBug users through and through. *

Thanks to Sean Callahan, Scott Douglass, and David Van Brink for reviewing this column.*


Community Search:
MacTech Search:

Software Updates via MacUpdate

World of Tanks Generals guide - Tips and...
World of Tanks Generals is a brand new card game by the developer behind the World of Tanks shooter franchise. It plays like a cross between chess and your typical card game. You have to keep in consideration where you place your tanks on the board... | Read more »
TruckSimulation 16 guide: How to succeed...
Remember those strangely enjoyable truck missions in Grand Theft Auto V whereit was a disturbing amount of fun to deliver cargo? TruckSimulation 16 is reminiscent of that, and has you play the role of a truck driver who has to deliver various... | Read more »
The best GIF making apps
Animated GIFs have exploded in popularity recently which is likely thanks to a combination of Tumblr, our shorter attention spans, and the simple fact they’re a lot of fun. [Read more] | Read more »
The best remote desktop apps for iOS
We've been sifting through the App Store to find the best ways to do computer tasks on a tablet. That gave us a thought - what if we could just do computer tasks from our tablets? Here's a list of the best remote desktop apps to help you use your... | Read more »
Warhammer 40,000: Freeblade guide - How...
Warhammer 40,000: Freebladejust launched in the App Store and it lets you live your childhood dream of blowing up and slashing a bunch of enemies as a massive, hulking Space Marine. It's not easy being a Space Marine though - and particularly if... | Read more »
Gopogo guide - How to bounce like the be...
Nitrome just launched a new game and, as to be expected, it's a lot of addictive fun. It's called Gopogo, and it challenges you to hoparound a bunch of platforms, avoiding enemies and picking up shiny stuff. It's not easy though - just like the... | Read more »
Sago Mini Superhero (Education)
Sago Mini Superhero 1.0 Device: iOS Universal Category: Education Price: $2.99, Version: 1.0 (iTunes) Description: KAPOW! Jack the rabbit bursts into the sky as the Sago Mini Superhero! Fly with Jack as he lifts impossible weights,... | Read more »
Star Wars: Galaxy of Heroes guide - How...
Star Wars: Galaxy of Heroes is all about collecting heroes, powering them up, and using them together to defeat your foes. It's pretty straightforward stuff for the most part, but increasing your characters' stats can be a bit confusing because it... | Read more »
The best cooking apps (just in time for...
It’s that time of year again, where you’ll be gathering around the dinner table with your family and a huge feast in front of you. [Read more] | Read more »
Square Rave guide - How to grab those te...
Square Rave is an awesome little music-oriented puzzle game that smacks of games like Lumines, but with its own unique sense of gameplay. To help wrap your head around the game, keep the following tips and tricks in mind. [Read more] | Read more »

Price Scanner via

Cyber Monday: Apple MacBooks on sale for up t...
Apple resellers have MacBook Pros, MacBook Airs, and MacBooks on sale for up to $250 off MSRP for Cyber Monday 2015. The following is a roundup of the lowest prices available for new models from any... Read more
Cyber Monday: 15% off Apple products, and sto...
Use code CYBER15 on Cyber Monday only to take 15% on Apple products at Target, and store-wide. Choose free shipping or free local store pickup (if available). Sale prices for online orders only, in-... Read more
iPad Air 2 And iPad mini Among Top Five Black...
Adobe has released its 2015 online shopping data for Black Friday and Thanksgiving Day. The five best selling electronic products on Black Friday were Samsung 4K TVs, Apple iPad Air 2, Microsoft Xbox... Read more
All-in-one PC Shipments Projected To Drop Ove...
Digitimes’ Aaron Lee and Joseph Tsai report that all-in-one (AIO) PC shipments may drop a double-digit percentage on-year in 2015 due to weaker-than-expected demand, although second-largest AIO make... Read more
Sprint Offers iPad Pro
Sprint now offers Apple’s new iPad Pro with Wi-Fi + Cellular, featuring a 12.9-inch Retina display with 5.6 million pixels. Customers can pick up iPad Pro at select Sprint retail locations. It can... Read more
Cyber Monday: Target offers 15% discount on A...
Target has discounted Apple Watches by 15% for Cyber Monday. Choose free shipping or free local store pickup (if available). Sale prices for online orders only, in-store prices may vary: - Apple... Read more
Sunday roundup of Holiday weekend Mac sales:...
Take up to $500 off MSRP on the price of a new Mac at B&H Photo today as part of their Black Friday/Holiday weekend sale. Shipping is free, and B&H charges NY tax only. These prices are... Read more
Holiday weekend: Apple Watch on sale for $50-...
B&H Photo has the Apple Watch on sale today for $50-$100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - Apple Watch Sport: $50 off - Apple Watch: $50-$100 off Read more
Holiday weekend: iPad Air 2s on sale for up t...
B&H Photo has iPad Air 2s on sale for up to $80 off MSRP including free shipping plus NY sales tax only: - 16GB iPad Air 2 WiFi: $459 $40 off - 64GB iPad Air 2 WiFi: $569 $30 off - 128GB iPad Air... Read more
Holiday weekend Mac sales roundup: B&H Ph...
B&H Photo continues to have all new Macs on sale for up to $500 off MSRP as part of their Black Friday/Holiday weekend sale. Shipping is free, and B&H charges NY tax only: - 15″ 2.2GHz Retina... Read more

Jobs Board

Technical Program Manager, Strategic Merchant...
# Technical Program Manager, Strategic Merchants - Apple Pay Job Number: 44001177 Santa Clara Valley, Califo ia, United States Posted: Oct. 30, 2015 Weekly Hours: 40.00 Read more
Frameworks Engineer, *Apple* Watch - Apple...
# Frameworks Engineer, Apple Watch Job Number: 41403122 Santa Clara Valley, Califo ia, United States Posted: Jul. 1, 2015 Weekly Hours: 40.00 **Job Summary** Join the Read more
Software Engineer - *Apple* Pay - Apple (Un...
# Software Engineer - Apple Pay Job Number: 44003246 Santa Clara Valley, Califo ia, United States Posted: Nov. 16, 2015 Weekly Hours: 40.00 **Job Summary** Apple Pay Read more
Merchant Operations Manager: *Apple* Pay -...
# Merchant Operations Manager: Apple Pay Job Number: 43593822 Santa Clara Valley, Califo ia, United States Posted: Nov. 10, 2015 Weekly Hours: 40.00 **Job Summary** The Read more
Product Design Engineer - *Apple* Watch - A...
# Product Design Engineer - Apple Watch Job Number: 41727161 Santa Clara Valley, Califo ia, United States Posted: Jul. 22, 2015 Weekly Hours: 40.00 **Job Summary** Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.