TweetFollow Us on Twitter

Sep 92 Letters
Volume Number:8
Issue Number:5
Column Tag:Letters

Dialogue Box

By Neil Ticktin, Editor

Math Equations Ommission

I just received my writer's letter for my contribution to MacTutor. Thank you for the complimentary copy of July's MacTutor and thanks for the handsome cheque!

OOPs. Unfortunately you omitted the listing of the file CustomFn.c. In its place you printed Demo.c. CustomFn.c is an integral part of the compiler and the missing code will leave your readers wondering. [For those readers who need it, write to Xplain Corp. for the source code disk. This listing is on it. - Ed.]

- Dr. Kevin Raner

How many suggestions can you make in a letter?

l am very excited at the rebirth of MacTutor. As a person living in a foreign country, it is very difficult to find information on programming in English (especially stuff that does not cost a fortune). MacTutor provides a source of information on programming as well as tools that are available. l would like to offer my input on the following things.

1. Please make sure to include the fax and phone numbers for things mentioned in your magazine. [We give the fax numbers whenever we are given them. We’ll try even harder to get them in the future. - Ed.]

2. l would also like to see a classified listing in the magazine. For example, I am trying to do some programming in assembly language but l can not find any books in print regarding the subject. l would like to be able to place an ad requesting or offering these types of materials as well as others. [We are looking into such a section for later this year. - Ed.]

3. l would also like to see a greater diversity of types of programs. For example, programs that read and write data to the SCSI port, input device manipulation, and communications. [We are working on getting hardware articles that address some of these topics. - Ed.]

Again, l look forward to many interesting and helpful articles in the future and l wish MacTutor the best of luck.

- Brett Bibby, Kanebo, Ltd.

Modify Print Dialogs Article Corrections

First let me thank you for publishing my article “Modify Print Dialogs” in the June 1992 issue of MacTutor. It was a thrill to see it in print.

There where a couple of minor bugs in the code. The program usually operates “As Advertised”, but under some conditions the wrong radio button could be disabled.

In the DisableDraftMode routine there are three lines which look like:

if ((*the_title)  -=  (*draft_title))

This really only checks that the first letter of the title matches (in this case) draft_title. These lines should be changed to use strcmp, as in:

if (Istrcmp(the_title,  draft_title))

I also left out a small block of code at the end of the DisableDraftMode routine. After the end of the main for loop and before the ) which ends the routine, add the following lines:

/* 1 */
if (  draft_selected  )  {
/*  draft  mode  was  selected,  so  select  the  next  best  */ 
 if  (  better_item_no  )  item_no  =  better_item_no, else
 if  (  best_item_no  )  item_no  =  best_item_no,

GetDItem((DialogPtr)  theDialogPtr,  item_no,  &the_type,  &the_item, 
 &the_box), SetCtlValue((ControlHandle)  the_item,  1),
}

The variables better_item_no and best_item_no should also be initialized to zero at the start of the routine.

I hope this didn’t cause anyone too much grief. Boy, is my face red!

- Greg WiIson, Ontario , Canada

Two Seconds

I take 2 seconds to drop you a word:

Carry on the good work !!

We like and need you.

- JC Hadorn

How Long can an article be?

BigNum Article

You say you knew you were not including all the code? My goodness!! If you knew, you could have at least put in an editor's comment in brackets to tell readers where the code was. [You are right, we should have and will try to do so in the future. - Ed.]

I still think massive shrinking of the code to a very tiny size would be the best alternative to elimination of code. [Our readers have told us not to do this because they want to be able to read the code. If it is small they can’t read it.- Ed.]

I never send to MacTutor any code that is not relevant, and I explain in minute detail what's what.

[The reason that the code was cut was because the article was already 12 pages long and the rest of the code would not fit. Although Lisp is of interest to our readers, we need to make sure that we stay reasonable on the amount of Lisp in the magazine. If the code was put in, almost 25% of the magazine would have been Lisp. The real solution here is to give the readers the important information and not hold their hand through the code. Of course, as always, ALL the code is available on the source code disk which anyone can get by calling MacTutor. - Ed.]

- André van Meulebrouck

Sounds good to me!

I was in process of letting my MacTutor subscription drop (again) when you folks took it over. The first couple of issues look pretty good. I hope you work harder than the old owners at showing good, useful code and avoiding their tendency to send out buggy or compatibility-challenged stuff. It is somewhat depressing to see the only technical journal for the Mac publish stuff that consistently ignores both Apple HI and Apple Compatibility standards, because that comes back and hurts the readers when things start breaking (worse, apple gets blamed for it, even though mama apple said "no no!"). I also constantly got heebie-jeebies from the rampant typos and basic copy-editing mistakes (in my other life, I'm a writer). If they couldn't get the article right, how can you trust the code?

[Nowadays, we try to test the code and get a feel for whether it is any good. Although ultimately, the responsibility needs to be both the article’s author and yours because we cannot test every bit of code as extensively as you would like. In the meantime, we are keeping vigilant on reports of problems with code and printing that information. This way, we use the entire Macintosh community to check over code. We hear you and will do the best that we reasonably can. - Ed.]

I'd also like to see more of a focus on the primary languages (Think, MPW) and less on the esoterica (Lisp, Fortran, Forth). Make it a journal for the folks doing the leading edge, which the side languages aren't. They're hobbyist toys.

And does anyone really find the Mousehole stuff useful? I'd rather see a more focussed "Ask the expert" column where questions get real answers rather than a random data stream where I have no clue if they know what they're talking about. [We actually do get a lot of compliments on the Mousehole, but I will keep both your comments in mind. - Ed.]

It was cute when MacTutor was three guys in a garage, but this is a real magazine now.

Dave Mark is a great addition to the team. [We think so too. - Ed.]

Keep it up.

Good luck!

- Chuq Von Rospach

Speeding up Random Numbers

I was glad to see Jon Bell's recap of Lemer's method and Park and Miller's excellent paper on minimal standard random number generators (cacm v31n10). This is an important area for implementers to learn about since the effort required to do it right is very low, and the results of doing it wrong can be disasterous. The further excursion into assembly level coding leaves a bit to be desired, though. If speed is what you're after, the following routine

;2
UpdateSeed
    MOVE.L  seed(A5), D1
    MULU.L#33614, D0:D1
 ; 33614 is 16807 * 2
    LSR.L   #1, D1
    ADD.L   D0, D1
    BPL.S   @1
    ADDI.L  #$80000001, D1
@1  MOVE.L  D1, seed(A5)
    RTS

takes less than half as much time as the one presented in the article, and computes the same result. This code takes advantage of the fact that the modulus is one less than a power of two. There is no need in this case to perform a divide to find the remainder. To convince yourself that it works, think about multiplying mod 9 (one less than a power of 10). (3 * 4) mod 9 = 12 mod 9 = 3, note that 3 is 1 + 2, the digits of the result of the multiplication. The only complication is when the sum overflows (e.g., (8 * 8) mod 9 = 64 mod 9 = 1, 6 + 4 = 10... 1 + 0 = 1). In this case we need to "carry around" in the result as is done by the ADDI above.

Lemer's method is important when the facilities of a CISC processor are not available (as in Pascal or C), but carrying the technique into (CISC) assembly code is inappropriate. In particular, even without the power of two minus one requirement of my implementation, it is not necessary to do two separate multiplies in Update Seed since the M680x0 will do double precision multiplies and divides...

;3
UpdateSeed
    MOVE.L  seed(A5), D0
    MULU.L  #a, D1:D0
    DIVS.L  #m, D1:D0
    MOVE.L  D1, seed(A5)
    RTS

Also, neither of these UpdateSeed routines suffer from the need to artificially restrict the range of the multiplier “a” -- although I've never been tempted to search for my own values: I recommend you stick with the values tested and certified by the experts.

Regards,

- Doug Currie

Flavors Technology, Inc.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Firefox 37.0 - 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
Arq 4.11 - Online backup to Google Drive...
Arq is super-easy online backup for the Mac. Back up to your own Google Drive storage (15GB free storage), your own Amazon Glacier ($.01/GB per month storage) or S3, or any SFTP server. Arq backs up... Read more
MacFamilyTree 7.3.4 - Create and explore...
MacFamilyTree gives genealogy a facelift: it's modern, interactive, incredibly fast, and easy to use. We're convinced that generations of chroniclers would have loved to trade in their genealogy... Read more
Yummy FTP 1.10.2 - FTP/SFTP/FTPS client...
Yummy FTP is an FTP + SFTP + FTPS file transfer client which focuses on speed, reliability and productivity. Whether you need to transfer a few files or a few thousand, schedule automatic backups, or... Read more
VueScan 9.5.08 - Scanner software with a...
VueScan is a scanning program that works with most high-quality flatbed and film scanners to produce scans that have excellent color fidelity and color balance. VueScan is easy to use, and has... Read more
Iridient Developer 3.0.1 - 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
Air Video Server HD 2.1.0 - Stream video...
Air Video Server HD streams videos instantly from your computer on your iPhone, iPad, iPod touch or Apple TV. No need to worry about converting or transferring files. We took everything that was... Read more
Duplicate Annihilator 5.7.5 - Find and d...
Duplicate Annihilator takes on the time-consuming task of comparing the images in your iPhoto library using effective algorithms to make sure that no duplicate escapes. Duplicate Annihilator... Read more
BusyContacts 1.0.2 - 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
Capture One Pro 8.2.0.82 - RAW workflow...
Capture One Pro 8 is a professional RAW converter offering you ultimate image quality with accurate colors and incredible detail from more than 300 high-end cameras -- straight out of the box. It... Read more

2K Announces WWE 2K, Mobile's First...
It seems like this month has been pretty big for wrestling. First Wrestlemania, then 2K has announces that they're releasing  WWE 2K for iOS. It's a simulation-based WWE game where you'll get to play with several WWE superstars such as John Cena, ... | Read more »
How the Apple Watch Could Change the Fac...
The Apple Watch is still a ways out, but my previous musings on the wearable’s various features got me thinking: what might it be like a year after launch? Two years? Five years? What if it becomes a symbiotic part of the iOS framework to the point... | Read more »
Pie In The Sky: A Pizza Odyssey (Games)
Pie In The Sky: A Pizza Odyssey 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: A game about delivering pizza. In space. | Read more »
Chosen Gives Hopeful Singers, Songwriter...
If YouTube videos and reality TV shows like The Voice have taught us one thing, it’s that there are a lot of people out there who are anxious to show the world their talents. And if they’ve taught us a second thing, it’s that there’s an almost... | Read more »
Android's Popular OfficeSuite Now A...
Once only available for Android devices, OfficeSuite has finally landed on the app store. The Mobile Systems app lets you view, edit, create, and share Word, Excel, and PowerPoint documents as well as convert them to/from PDFs. It's touted as being... | Read more »
Warhammer: Arcane Magic is Coming Soon,...
Turbo Tape Games has announced that they're joining forces with Games Workshop to bring the turn-based strategy board game, Warhammer: Arcane Magic, to life on the iOS. | Read more »
Fast & Furious: Legacy's Creati...
| Read more »
N-Fusion and 505's Ember is Totally...
| Read more »
These are All the Apple Watch Apps and G...
The Apple Watch is less than a month from hitting store shelves, and once you get your hands on it you're probably going to want some apps and games to install. Fear not! We've compiled a list of all the Apple Watch apps and games we've been able to... | Read more »
Appy to Have Known You - Lee Hamlet Look...
Being at 148Apps these past 2 years has been an awesome experience that has taught me a great deal, and working with such a great team has been a privilege. Thank you to Rob Rich, and to both Rob LeFebvre and Jeff Scott before him, for helping me... | Read more »

Price Scanner via MacPrices.net

Adobe Brings Powerful Layout-Design Capabilit...
Adobe today announced the availability of Adobe Comp CC, a free iPad app that enables rapid creation of layout concepts for mobile, Web and print projects. With Comp CC, designers can rough out and... Read more
Apple offering refurbished 27-inch 5K iMacs f...
The Apple Store is offering Apple Certified Refurbished 27″ 3.5GHz 5K iMacs for $2119 including free shipping. Their price is $380 off the price of new models, and it’s the lowest price available for... Read more
16GB iPad mini on sale for $199, save $50
Walmart has 16GB iPad minis (1st generation) available for $199.99 on their online store, including free shipping. Their price is $50 off MSRP. Online orders only. Read more
New 128GB MacBook Airs on sale for $50 off MS...
 B&H Photo has 128GB 11″ and 13″ 2015 MacBook Airs on sale today for $50 off MSRP including free shipping plus NY sales tax only: - 11″ 1.6GHz/128GB MacBook Air (Model #MJVM2LL/A): $849 $50 off... Read more
13-inch 2.6GHz Retina MacBook Pro (refurbishe...
The Apple Store has Apple Certified Refurbished 13″ 2.6GHz/128GB Retina MacBook Pros available for $979 including free shipping. Original MSRP for this model was $1299. Read more
Save up to $600 with Apple refurbished Mac Pr...
The Apple Store is offering Apple Certified Refurbished Mac Pros for up to $600 off the cost of new models. An Apple one-year warranty is included with each Mac Pro, and shipping is free. The... Read more
Samsung Galaxy S 6 and Galaxy S 6 edge U.S. P...
Samsung Electronics America, Inc. has announced the Galaxy S 6 and Galaxy S 6 edge will be available in the U.S. beginning April 10, with pre-orders being accepted now. “We have completely reimagined... Read more
13-inch 2.5GHz MacBook Pro (refurbished) avai...
The Apple Store has Apple Certified Refurbished 13″ 2.5GHz MacBook Pros available for $829, or $270 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.... Read more
Save up to $80 on iPad Air 2s, NY tax only, f...
 B&H Photo has iPad Air 2s on sale for $80 off MSRP including free shipping plus NY sales tax only: - 16GB iPad Air 2 WiFi: $469.99 $30 off - 64GB iPad Air 2 WiFi: $549.99 $50 off - 128GB iPad... Read more
iMacs on sale for up to $205 off MSRP
B&H Photo has 21″ and 27″ iMacs on sale for up to $205 off MSRP including free shipping plus NY sales tax only: - 21″ 1.4GHz iMac: $1019 $80 off - 21″ 2.7GHz iMac: $1189 $110 off - 21″ 2.9GHz... Read more

Jobs Board

DevOps Software Engineer - *Apple* Pay, iOS...
**Job Summary** Imagine what you could do here. At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring Read more
*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
Sr. Technical Services Consultant, *Apple*...
**Job Summary** Apple Professional Services (APS) has an opening for a senior technical position that contributes to Apple 's efforts for strategic and transactional Read more
Lead *Apple* Solutions Consultant - Retail...
**Job Summary** Job Summary The Lead ASC is an Apple employee who serves as the Apple business manager and influencer in a hyper-business critical Reseller's store Read more
*Apple* Pay - Site Reliability Engineer - Ap...
**Job Summary** Imagine what you could do here. At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.