TweetFollow Us on Twitter

June 96 - The Veteran Neophyte: Manual Labor

The Veteran Neophyte: Manual Labor

JIM MENSCH

As a 14-year Apple veteran, why would I be writing a "neophyte" column? It's true that I've written system software for many Apple computers and I've been in every tech support capacity that Apple has ever dreamed of. I'm writing this because I'm in fact still wet behind the ears; I learn new things every day here at Apple. Most of what I learn involves problem solving and debugging. I believe that creative problem solving is the one trait that separates a great programmer from an average programmer. Great programmers must hone their problem-solving skills all the time, whether at a computer or not. In fact, sometimes examining how day-to-day problems are solved can help us develop proper coding and debugging skills at work. Here I'd like to relate a little fable to illustrate this point (the names have been changed to protect my automotive pride).

A FABLE

Bob and Stu were working on a primo 1963 Dodge Dart that they had just bought. It was a classic: push-button transmission, cherry upholstery, straight body. A classic car with a classic problem: it had been run dry of oil and the engine needed to be rebuilt. Flush with confidence (having just completed an engine rebuilding course at the local community college), Bob said, "No problem, man. Let's rebuild it ourselves; how hard can it be?" That, I suppose, was the first mistake.

So, Bob and Stu set out to rebuild the engine, using all new parts. A scant two months later, the ten-hour job was finished. Finally they were ready to install the engine. Struggling to get the 1000-pound engine into the car and onto two very small bolts that hold it at an angle too obtuse to allow it to drop in straight, they were cussing and cutting themselves constantly.

After a while it dawned on them that things were not going as planned. In a moment of brilliance, Stu said, "Hey, what does the manual say about installing this thing?" The manual! Every good car mechanic has a manual and follows it. Why didn't I -- er, Bob -- think of that? Reading the manual, they found that the torque converter (a big heavy round thing with teeth on it) was supposed to be mounted not to the engine but to the transmission!

They pulled out the engine and struggled for an hour to get the converter mounted to the transmission. After this the engine went in relatively easily (with the help of Thom the helpful Brit). Having connected all the hoses, belts, doodads, and whatnots, our intrepid pair looked at each other with giddy anticipation. "Could it be that we're ready to start this thing?" they wondered. So they tried to start it -- and they failed to start it. Just as with every major programming project, they had put in countless hours, and when the time came to fire the baby up, nothing happened.

It was time to debug this problem. "Hmm. Seems like a compression problem. Do we have compression?" asked Stu. "Yup, it's low, about 60%, but I guess that's because the engine hasn't been broken in yet," replied Bob. Were the plugs firing? Ground one side, turn out the lights, look for the blue spark: of course they were firing. Was the gas getting to the carburetor? Not yet, so they siphoned some up and tried again. Still no go.

So they started looking at the esoteric stuff. Was the timing chain on correctly? Well, we have compression, and it seems that we shouldn't if the timing is wrong. Three hours later, after Bob browbeat Stu into agreeing that the timing must be correct, Stu browbeat Bob into testing it anyway, since while Bob talked a good game it was always possible that he was wrong. They partly disassembled the engine and watched the little valve bits go up and down, and sure enough the timing was right. A victory for Bob, hollow as it may have been.

They continued to argue about what the problem could be, and finally decided to let it rest a while. This went on for weeks, until one day Bob remembered something that his teacher told him in class: a tablespoon of oil in every cylinder will get the seals sealing so that an engine could start. Could it be that easy? Could it be that the first thing that they had looked at -- the compression -- was in fact what was preventing the engine from starting? Bob put a little oil in each spark plug hole and the mighty engine roared to life! Our heroes stood dumbfounded at first, then quietly patted themselves on the back for such a fine job. Months after they had started their odyssey, they finally got the beast running.

YOU'RE NEVER TOO SMART TO READ THE MANUAL

The first thing to notice is that reading the manual was not the first step Bob and Stu took toward solving their problem. Neglecting to read the manual cost them hours of avoidable frustration and rework. Like Inside Macintosh, automotive manuals contain many hidden gems that are there for the asking. For instance, the shop manual didn't explicitly say, "Don't be a moron; the torque converter stays attached to the transmission!" but it did say, "Step 9. Remove torque flex plate screws, leaving converter attached to transmission."

Inside Macintosh contains many such tidbits waiting to be found. For instance, I was recently asked by a developer why a particular call to close a window wasn't causing the window behind it to redraw properly (it was leaving a desktop-patterned hole behind). Examining the problem a little further, we found that a resource that was needed had been purged and wasn't being reloaded. The code was smart enough not to crash when the purged resource was discovered, but it didn't seem to be able to reload the thing. As it turns out, the developer was using a rather strange strategy for manipulating the ResLoad attribute of the Resource Manager. He was turning it off when he wanted it off but not turning it back on again right away; instead he would turn it back on when he needed it on. I pointed out to the him that this was the problem, and he said, "I've been programming the Mac for almost 10 years and I've never read anywhere that the Window Manager assumes ResLoad is TRUE!"

While he's right about this on the surface, if we look we find that Inside Macintosh warns in the SetResLoad description that "If you call SetResLoad with the load parameter set to FALSE, be sure to . . . set [it] to TRUE as soon as possible. Other parts of system software that call the Resource Manager expect this value to be TRUE." (This has been in there so long that Caroline Rose wrote the first draft of it!) Since the WDEF is system software, it assumed that ResLoad would in fact be TRUE. After I pointed this out, the developer decided it was time to break out those manuals that had been collecting dust for so many years, and revisit some of the documentation he thought he had remembered.

YOUR FIRST INSTINCT IS USUALLY THE BEST

Another lesson to learn is that when problems arise, don't spend hours plodding through esoteric logic. First think, "What's the most obvious cause of this problem?" You might recall that Stu was right when he suspected a compression problem. By discarding the obvious without first examining it fully, we risk costing ourselves days of work only to find out that we were right all along. As a seasoned programmer, you'll learn that you can get a feel for why a problem exists. You may not have any ready logic to explain why an event occurred, but you might have a feeling anyway. Go with that feeling. The obvious things are the easiest to check (but don't make it too easy and stare past the real trouble). They're also usually the quickest to fix. Looking there first can save time, effort, aggravation, and lots of cussing. In my 14 years of problem solving for Apple, I've found that the simple, obvious solution is right 90% of the time.

CONFIRM YOUR LOGIC WITH REAL EXAMPLES

Why did Bob and Stu retest the timing, anyway? Experienced troubleshooters, they realized that simply arguing about a point may lead to a conclusion, but any conclusion that can be tested should be. Logic dictates that the cam shaft can be 180deg. out of phase (for every rotation of the cam shaft, the crankshaft rotates twice and thus will be in the same position at 0deg. cam rotation as 180deg. cam rotation), but you should check it anyway if you're stuck. It's easy to get your logical conclusions backwards and get your crankshaft 180deg. out of phase. On a car this might result in outright failure, while on a computer it can mean more insidious things.

I recently needed to use the Power Manager to control screen dimming, drive spindown, and CPU sleep. All of the calls had a "get" function that returned a Boolean, TRUE if the feature was on or FALSE if it was off. Strangely enough, two of the "set" calls required a value of TRUE to enable the feature but one required TRUE to disable the feature. I spent hours looking at the complex logic of IF statements before I simply watched it all go by in MacsBug and noticed that I was sending a TRUE value to a call named Disable. Going back through my logic again brought the error right out.

BACK TO WORK

If you've learned anything from the above tale, good. Remember, manuals contain quite a lot of information and they're a good place to start. Also remember that this isn't rocket (or automotive) science. Think simple thoughts; don't create extra work for yourself.

JIM MENSCH (mensch@applelink.apple.com, AppleLink MENSCH) has spent the last 14 years as a wage slave at Apple. Before that he did real work that involved cleaning and lifting and toting stuff and working with tools. While his mother is his real inspiration in life, he looks to the relaxed masses for guidance. An avid book collector and cook, he has absolutely no time for computers when he's not at work. His personal motto is "Eat more beets."*

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Path Finder 7.5 - Powerful, award-winnin...
Path Finder makes you a master of file management. Take full control over your file system. Save your time: compare and synchronize folders, view hidden files, use Dual Pane and full keyboard... Read more
Merlin Project 4.2.3 - $349.00
Merlin Project is the leading professional project management software for OS X. If you plan complex projects on your Mac, you won’t get far with a simple list of tasks. Good planning raises... Read more
TextSoap 8.4 - Automate tedious text doc...
TextSoap can automatically remove unwanted characters, fix up messed up carriage returns, and do pretty much anything else that we can think of to text. Save time and effort. Be more productive. Stop... Read more
Smultron 9.4 - Easy-to-use, powerful tex...
Smultron 9 is an elegant and powerful text editor that is easy to use. Use it to create or edit any text document. Everything from a web page, a note or a script to any single piece of text or code.... Read more
QuarkXPress 13.0.0.0 - Desktop publishin...
QuarkXPress 2017 is the new version that raises the bar for design and productivity. With non-destructive graphics and image editing directly within your layout, you no longer have to choose between... Read more
Brackets 1.9.0 - Open Source Web design...
Brackets is an Open-Source editor for Web design and development built on top of Web technologies such as HTML, CSS, and JavaScript. The project was created and is maintained by Adobe, and is... Read more
Audio Hijack 3.3.4 - Record and enhance...
Audio Hijack (was Audio Hijack Pro) drastically changes the way you use audio on your computer, giving you the freedom to listen to audio when you want and how you want. Record and enhance any audio... Read more
Tunnelblick 3.7.1a - GUI for OpenVPN.
Tunnelblick is a free, open source graphic user interface for OpenVPN on OS X. It provides easy control of OpenVPN client and/or server connections. It comes as a ready-to-use application with all... Read more
Amazon Chime 4.3.5721 - Amazon-based com...
Amazon Chime is a communications service that transforms online meetings with a secure, easy-to-use application that you can trust. Amazon Chime works seamlessly across your devices so that you can... Read more
BBEdit 11.6.6 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more

Latest Forum Discussions

See All

Jaipur: A Card Game of Duels (Games)
Jaipur: A Card Game of Duels 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: ** WARNING: iPad 2, iPad Mini 1 & iPhone 4S are NOT compatible. ** *** Special Launch Price for a limited... | Read more »
Subdivision Infinity (Games)
Subdivision Infinity 1.03 Device: iOS Universal Category: Games Price: $2.99, Version: 1.03 (iTunes) Description: Launch sale! 40% Off! Subdivision Infinity is an immersive and pulse pounding sci-fi 3D space shooter. https://www.... | Read more »
Clash of Clans' gets a huge new upd...
Clash of Clans just got a massive new update, and that's not hyperbole. The update easily tacks on a whole new game's worth of content to the hit base building game. In the update, that mysterious boat on the edge of the map has been repaired and... | Read more »
Thimbleweed Park officially headed to iO...
Welp, it's official. Thimbleweed Park will be getting a mobile version. After lots of wondering and speculation, the developers confirmed it today. Thimbleweed Park will be available on both iOS and Android sometime in the near future. There's no... | Read more »
Pokémon GO might be getting legendaries...
The long-awaited legendary Pokémon may soon be coming to Pokémon GO at long last. Data miners have already discovered that the legendary birds, Articuno, Moltres, and Zapdos are already in the game, it’s just a matter of time. [Read more] | Read more »
The best deals on the App Store this wee...
If you’ve got the Monday blues we have just the thing to cheer you up. The week is shaping up to be a spectacular one for sales. We’ve got a bunch of well-loved indie games at discounted prices this week along with a few that are a little more... | Read more »
Honor 8 Pro, a great choice for gamers
Honor is making strides to bring its brand to the forefront of mobile gaming with its latest phone, the Honor 8 Pro. The Pro sets itself apart from its predecessor, the Honor 8, with a host of premium updates that boost the device’s graphical and... | Read more »
The 4 best outdoor adventure apps
Now that we're well into the pleasant, warmer months, it's time to start making the most of the great outdoors. Spring and summer are ideal times for a bit of trekking or exploration. You don't have to go it alone, though. There are plenty of... | Read more »
Things 3 (Productivity)
Things 3 3.0.1 Device: iOS iPhone Category: Productivity Price: $7.99, Version: 3.0.1 (iTunes) Description: Meet the all-new Things! A complete rethinking of the original, award-winning task manager – with a perfect balance between... | Read more »
Oddball mash-up Arkanoid vs Space Invade...
In a move no one was really expecting, Square Enix has put forth an Arkanoid/Space Invaders mash-up aptly titled Arkanoid vs Space Invaders. The game launched today on both iOS and Android and the reviews are actually quite good. [Read more] | Read more »

Price Scanner via MacPrices.net

A Kaby Lake Processor Upgrade For The MacBook...
Now they tell me! Well, actually Apple hasn’t said anything official on the subject, but last week Bloomberg News’s Mark Gurman and Alex Webb cited unnamed “people familiar with the matter”... Read more
Kodak’s Camera-First Smartphone EKTRA Launche...
The Eastman Kodak Company and Bullitt Group have announced the availability of a U.S. GSM version of the KODAK EKTRA Smartphone. The U.S. launch coincides with a software update addressing requests... Read more
Apple Launches App Development Curriculum for...
Apple today launched a new app development curriculum designed for students who want to pursue careers in the fast-growing app economy. The curriculum is available as a free download today from Apple... Read more
Check Apple prices on any device with the iTr...
MacPrices is proud to offer readers a free iOS app (iPhones, iPads, & iPod touch) and Android app (Google Play and Amazon App Store) called iTracx, which allows you to glance at today’s lowest... Read more
9.7-inch 2017 iPad available for $298, save $...
Sams Club has 32GB 9.7″ Apple iPads available for $298 for Sams Club members. That’s $21 off MSRP. Order online and choose free local store pickup (if available) or free shipping. Read more
touchbyte Releases PhotoSync 3.2 for iOS With...
Hamburg, Germany based touchbyte has announced the release of PhotoSync 3.2 for iOS, a major upgrade to the versatile and powerful app to transfer, backup and share photos and videos over the air.... Read more
Emerson Adds Touchscreen Display and Apple Ho...
Emerson has announced the next evolution of its nationally recognized smart thermostat. The new Sensi Touch Wi-Fi Thermostat combines proven smarthome technology with a color touchscreen display and... Read more
SurfPro VPN for Mac Protects Data While Offer...
XwaveSoft has announced announce the release and immediate availability of SurfPro VPN 1.0, their secure VPN client for macOS. SurfPro VPN allows Mac users to protect their internet traffic from... Read more
13-inch Touch Bar MacBook Pros on sale for $1...
B&H Photo has 13″ MacBook Pros in stock today for up to $150 off MSRP. Shipping is free, and B&H charges NY & NJ sales tax only: - 13″ 2.9GHz/512GB Touch Bar MacBook Pro Space Gray (... Read more
Tuesday deal: $200 off 27-inch Apple iMacs
Amazon has select 27″ iMacs on sale for $200 off MSRP, each including free shipping: - 27″ 3.3GHz iMac 5K: $2099 $200 off MSRP - 27″ 3.2GHz/1TB Fusion iMac 5K: $1799 $200 off MSRP Keep an eye on our... Read more

Jobs Board

*Apple* Mobile Master - Best Buy (United Sta...
**508456BR** **Job Title:** Apple Mobile Master **Location Number:** 000040-Eau Claire-Store **Job Description:** **What does a Best Buy Apple Mobile Master Read more
Director *Apple* ERP Integration Lead - Ast...
…make a real difference. Come, shine with us! Astellas is announcing a Director Apple ERP Integration Lead opportunity in Northbrook, IL. Purpose & Scope: This role Read more
Director *Apple* Platform, IS Data Manageme...
…a real difference. Come, shine with us! Astellas is announcing a Director Apple Platform, IS Data Management Lead opportunity in Northbrook, IL. Purpose & Scope: Read more
Associate Director *Apple* Platform -- SAP...
…real difference. Come, shine with us! Astellas is announcing a Associate Director Apple Platform -- SAP Security, Risks and Controls Lead opportunity in Northbrook, Read more
*Apple* Media Products - Commerce Engineerin...
Apple Media Products - Commerce Engineering Manager Job Number: 57037480 Santa Clara Valley, California, United States Posted: Apr. 18, 2017 Weekly Hours: 40.00 Job Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.