TweetFollow Us on Twitter

Sep 86 Letters
Volume Number:2
Issue Number:9
Column Tag:Letters

Letters

Fortran Bugs

Jim Bishara

New Orleans

Help, Help, I can't get SetItemStyle toolbox call to work. I've spent at least 40 hours reading the Microsoft Fortran manual and no luck. I'm running a Mac Plus under Finder 4.1 (dumb Microsoft), with version 2.1. I used the DEMO.INC file supplied with the Fortran. When it tries to execute the trap, a bomb message returns ID=02. What can be wrong?

call toolbx(GetItemStyle, menuhandle, itemcount, chstyle) {works fine}

call toolbx(SetItemStyle,menuhandle,itemcount, chstyle) {bombs like a champ with ID 02}

[Probably the toolbx.par file is wrong. We've found lots of errors in it in the past. SetItemStyle probably is not a VAR. Just a guess. -Ed]

Aztec C 1.06H Release

Don McCauley

Ridgecrest, CA

I purchased my Aztec C from ComputerWare, a MacTutor advertiser, and on May 20, I received a beta release of version 1.06H, created May 12th. This time I received tens of pages of update documentation from their new manual, fresh off the press. Included with this update is an index. Unfortunately, the index seldom includes the key words I've looked for. For example, try to find in the index where to find how many characters are significant in a variable declaration? I've had trouble with multiple defined symbols using "theWindow" from Takatsuka's book Using the Macintosh Toolbox with C, page 70. Struct assignments in SetRects don't seem to work right for me. Any help for us Aztec'ers in the ABC's of C column? As far as HFS goes, basically it's "so far, so good" with this version. I really love the Manx UNIX like vi editor, Z. Manx is worth it just for z. I'm excited about C as a language and more specifically, about Aztec C for my Mac Plus.

[I'm sorry to report that Bob Gordon, our ABC's of C author, became seriously ill this month and has been unable to work on his C column for some time. We've talked to him and he reports he is beginning to recover and hopes to contribute another ABC article next month. We wish Bob a speedy recovery as I'm sure all our C fans do. A few notes and letters to Bob would be most appreciated I'm sure. Send them to Bob care of MacTutor and we will forward them on. -Ed.]

What's Wrong with this Picture?

move.l  #4, D0
_NewHandle
LEA   #$40E132,A1  ;get icon pointer in rom
move.l  A1, (A0) ;save pointer in new handle
 pea  top(A5)  ;set up rom call
move.l  A0, -(SP)  ;handle to icon
_PlotIcon ; plot it

[Note: I tried to write an assembly routine to plot the famous stolen icon from ROM memory, but it didn't work. -Ed.]

Icon Problem Above

Lon Kelly

College, AK

Thank you for your recent letter regarding the stolen icon problem. The simple explanation for the failure is that the line

LEA #$A0E132, A1

is not a legal 68000 assembler statement. This is because LEA will not use the immediate mode for the effective address field: only control addressing modes are allowable (see Morotola's Programmer's Reference Manual, p. 102 and p. 53). However, Mac C will assemble the line, setting the effective address bits as though it were a MOVE instruction. The linker listing shows the code actually generated:

Mac C Linker Listing:

4: 43 FC 00 40 E1 32    lea   #$40E132, A1
A: 20 89  move.l a1, (a0)
C: 48 6D FF  FC  pea top(a5)

Note that the first six bits indicate the effective address mode. Mac Nosy version 2.1 will disassemble the errant code without comment, as shown by the Nosy listing, but it loses track of 2 bytes and the next instruction:

Nosy output:

4: 43FC 0040 E132  LEA  #$40E1232,A1
; where did location A go?
C: 486D FFFC     PEA glob1(A5)

The Mac Zap listing shows that the code is actually on the disk as in the linker listing and that Nosy just got confused. It is interesting that Mac Zap and TMON, which have relatively simple disassemblers, recognize the illegality, while the assembler and Nosy do not.

Mac Zap Disassembly:

00F3C4  43FC   DC.W $43FC  ;illegal 

I believe you have another, more insideous problem doe to direct manipulation of "master pointers" created by _NewHandle. You seem to simply write over them. This leaves the memory manager with a master pointer pointing to ROM or to part of your code, rather than to a "relocatable block". I've never done this, but I sure expect it would cause problems with heap compaction, etc. What will happen if you call _DisposeHandle for a "handle" to ROM?

I think it would be a lot safer to do something like this: first make a constant pointer in your code, then push it's address (which would be a handle in the sense of a pointer to a pointer, but not in the context of the memory manager) as a parameter to _PlotIcon. See the untested suggestion below:

romicon:  dc.l   $40E132
 pea  top(a5)
 pea  romicon
 _PlotIcon

More on the Icon Problem

Peter Brown

La Mirada, CA

Thank you for your response to my letter. I have to admit my surprise at receiving it. You must be swamped wiath mail and I really appreciate your taking time out to write.

I took a look at the code you sent me and the stolen mac icon problem in particular. I banged in the whole listing as it stood and then fiddled around with it. The problem looked like this: the "LEA" instruction does not require use of the immediate mode designator, '#'. If it wasn't just a handwriting boo-boo, I'm surprised your assembler took the statement. [See previous letter. -Ed] This is possible pitfall #1. Well, to test things out using TMON, I inserted an:

LEA $40AD40, A1 ; NOTE FOR OLD ROMS

instruction at the spot in question, set the program counter to the beginning of ICONSTUFF: and let 'er rip (an instruction at a time). Lo and behold, I got a bunch of barbage in the output icon.

I then thought I'd trace through the ROM code to see what it looked like. The routine itself is pretty compact and straight forward, and no special handling of address registers. After a few different efforts, including getting garbage plotted from the icon data in RAM, I realized that the LEA 'ROM' location, A1 instruction assembled as 6 bytes, not 4 as with the LEA ICON, A1 which uses program counter relative addressing. I was coding over the next instruction! This is possible pitfall #2.

After re-assembling the file with the LEA $40AD40, A1 in place, (and no typos!), the code worked! Best of luck and keep up the great work with MacTutor.

 lea  icon, a1 ;assembles in 4 bytes 
 move.l a1, (a0) ;move pointer to a0 h
 pea   top(a5) ;push rect
 move.l a0, -(SP);push handle
 _PlotIcon;plot icon

[The advantage of being Editor of MacTutor, is that I have 6,000 "registered" programmers to call on for assistance! Thanks guys! -Ed]

Loves TML

Micahael Rollins

Broken Arrow, OK

I appreciate all the help your publication has provided over the last few months. There is nothing better than good examples to help learn a system as sophisticated as the Mac's. Since I have started using MacTutor and programming with TML's Pascal, I have managed to come a long way up the learning curve on the Mac. I find that I turn frequently to Mactutor for help with ROM calls and Resource Files that are not well explained in Inside Macintosh. I looke forward to each month's copy. Keep up the good work.

Tutor and TML Great

Terry Permeuter

Seattle, WA

Just got the TML Pascal compiler and saw an issue of MacTutor. Both look great! Enclosed is my check for a year's subscription. If you haven't done so yet, could you plan on an article or two on the differences between MacPascal and TML? The ads say TML compiles MacPascal programs, but I've already found some walls when trying that. A short guide on what to look for would be helpful! Keep up the good work!

[MacPascal is so non-standard that it is a dis-service to try and maintain compatibility with it. See the new LightSpeed Pascal, which IS TML compatible. -Ed]

Thanks for the Review

Dan Weston

Famous Assembly Author

I hope that by now you have received a final manuscript copy of volume two of the Complete Book of Macintosh Assembly Language Programming that you so thoroughly reviewed at the mid-way point. I was able to incorporate many of your suggestions into the final version, but not all. In particular, I didn't write anything about AppleTalk because I haven't ever had the opportunity to use it in any real situation. I think the strength of my books is that they are derived from my experience as a software developer, so I am reluctant to write about things that I have no direct experience with. Also, AppleTalk seems to be worth an entire book all by itself. I am very grateful for the comments that you made however, because I think they helped me produce a better book in the end.

I don't know exactly when we will go into final editing, but I assume that it will begin July sometime. I expect the final book out sometime in November. Thanks for the nice words in MacTutor on my new books!

Language Fanatic

David Adamski

Tulsa, OK

Well, I see by the EXP 5/1/86 notcie on my mailing label that it's time to renew my subscription to MacTutor. Enclosed please find my personal check for $30. MacTutor is one programming journal that I would NOT want to be without. Although I subscribe to a variety of computer publications, I look forward to receiving yours each month. As a language fanatic I feel that MacTutor is by far the most informative Journal, with regular articles on all the popular programming languages for the Mac. Sorry to hear about your robbery, hope my renewal helps you get back on track. Keep up the good work, and I wish you luck in the future. [MacTutor is enjoying great success this summer, thank you. -Ed.]

Questions

Bill Westcott

San Leandro

I got an idea! I've been trying to learn TML Pascal and Mac programming at the same time and your magazine has been a great help, but when my programs don't work, it's sort of like playing Zork. I keep trying everything till it works. Very time consuming. I noticed a green "3" sticker on one of my last MacTutor issues. That means that there are at least ten people in my three digit zip code who subscribe to your magazine. What do you think of a "Mac.Guru" program where people who know what they're doing might volunteer to answer stupid questions and your organization could somehow bring them together with askers of stupid questions? Just thought I'd ask. [Here's a stupid question: How would you do that? -Ed]

How do others do it?

J.M. Puckett

Austin, Tx

Oh No! I just received my April issue of MacTutor and on my label I see that my subscription is due to run out beginning of next month. So enclosed herein is a check for $30. Also I would like to know if you could send me an author's kit. I have just completed a series of desk accessories and applications using Megamax C, and am anxious to share some of the neat things I have found.

Yours is an excellent publication. I have learned a lot from it. However, I would like to submit a suggestion: Please suggest that some of your experts write articles on defining one's own menu, window, and control definitions. I have been attempting to write these kind of programming objects, and have had, for the most part, great success just by following the hints in Inside Macintosh; but I would sure like to see how others are creating such things. [Keep watching my Intermediate Mac'ing column especially last month's TML shell program. It had a lot of goodies! -Ed]

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Postbox 5.0.9 - Powerful and flexible em...
Postbox is a new email application that helps you organize your work life and get stuff done. It has all the elegance and simplicity of Apple Mail, but with more power and flexibility to manage even... Read more
VueScan 9.5.61 - 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
DiskCatalogMaker 6.5.16 - Catalog your d...
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... Read more
TrailRunner 3.8.827 - Route planning for...
TrailRunner is the perfect companion for runners, bikers, hikers, and all people wandering under the sky. Plan routes on a geographical map. Import GPS or workout recordings and journalize your... Read more
Civilization VI 1.0.1 - Next iteration o...
Sid Meier’s Civilization VI is the next entry in the popular Civilization franchise. Originally created by legendary game designer Sid Meier, Civilization is a strategy game in which you attempt to... Read more
Chromium 55.0.2883.75 - Fast and stable...
Chromium is an open-source browser project that aims to build a safer, faster, and more stable way for all Internet users to experience the web. Version 55.0.2883.75: Security fixes: High CVE-2016... Read more
Google Chrome 55.0.2883.75 - Modern and...
Google Chrome is a Web browser by Google, created to be a modern platform for Web pages and applications. It utilizes very fast loading of Web pages and has a V8 engine, which is a custom built... Read more
VirtualBox 5.1.10 - x86 virtualization s...
VirtualBox is a family of powerful x86 virtualization products for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers... Read more
Pixa 1.1.9 - Quickly and easily organize...
Pixa is an image-organizing application. The new app functions well, is easy to use, and helps people organize their images quickly and easily on their computers. For those who prefer not to use the... Read more
VirtualBox 5.1.10 - x86 virtualization s...
VirtualBox is a family of powerful x86 virtualization products for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers... Read more

Latest Forum Discussions

See All

Amateur Surgeon 4 Guide: Become the worl...
It's time to wield your trusty pizza cutter again, as Amateur Surgeon has returned with a whole fresh set of challenges (and some old, familiar ones, too). Starting anew isn't easy, especially when all you have at your disposal is a lighter, the... | Read more »
Le Parker: Sous Chef Extraordinaire (Ga...
Le Parker: Sous Chef Extraordinaire 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: | Read more »
Telltale Games really is working on a Gu...
Telltale Games' next episodic adventure is indeed Guardians of the Galaxy. A document tied to the voice actors strike suggested that the project was in the work, but now we have direct confirmation following an announcement at the Game Awards that... | Read more »
Amateur Surgeon returns to iOS and Andro...
Amateur Surgeon and its two sequels disappeared from the App Store some time and it was sad days for all. But now, just in time for the holidays, the Adult Swim favorite makes its joyous return in the shape of Amateur Surgeon 4, a remake with... | Read more »
The best board games on mobile
Sometimes you need to ditch all of the high speed, high action games in favor of something a little more traditional. If you don't feel like parting ways from your mobile device, though, there are still plenty of ways to get that old-school fix.... | Read more »
The best Facebook Messenger Instant Game...
Facebook's new Instant Games is now here, meaning you can play games with your friends directly via Facebook. It's a fun new way to connect with friends, of course, but it's also proving to be a solid gaming experience in its own right, with a... | Read more »
You can now play game's on Facebook...
Facebook launched its new Instant Games platform in an exciting new attempt to engage its user base. As a result, you can now play a number of different games directly through Facebook Messenger. All of these games run with HTML5, meaning you play... | Read more »
Apollo Justice Ace Attorney (Games)
Apollo Justice Ace Attorney 1.00.00 Device: iOS Universal Category: Games Price: $.99, Version: 1.00.00 (iTunes) Description: Court Is Back In Session Star as rookie defense attorney, Apollo Justice, as he visits crime scenes,... | Read more »
KORG iWAVESTATION (Music)
KORG iWAVESTATION 1.0 Device: iOS Universal Category: Music Price: $19.99, Version: 1.0 (iTunes) Description: A revolutionary new world of sound.The Wave Sequence Synthesizer for iPad - KORG iWAVESTATION | Read more »
Don't Grind Guide: Tips for becomin...
Don’t Grind is a surprising, derpy little one touch game with fun hand-drawn graphics. The goal is simple -- get the high score without being chopped to bits. That can be tough when you’re not used to the game, and that’s compounded by the fact... | Read more »

Price Scanner via MacPrices.net

Holiday sale: Apple MacBook Airs available fo...
B&H Photo has 13″ MacBook Airs on sale for $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 1.6GHz/128GB MacBook Air (MMGF2LL/A): $899 $100 off MSRP - 13″ 1.6GHz/... Read more
13-inch Silver Touch Bar MacBook Pro in stock...
Amazon has the new 2016 13″ 2.9GHz/256GB Silver Touch Bar MacBook Pro (MLVP2LL/A) in stock today and on sale for $1749 including free shipping. That’s $50 off MSRP, and it’s the lowest price... Read more
Parallels Toolbox 1.3 for Mac Offers 25 Singl...
Parallels has launched Parallels Toolbox 1.3 for Mac, an upgrade that adds five new utilities to the stand-alone application which was released in August and is available exclusively online at http... Read more
OWC Mercury Elite Pro Dual mini Ultra-Portabl...
OWC has introduced the new OWC Mercury Elite Pro Dual mini, a powerful yet ultra-portable dual-drive RAID solution. The new Mercury Elite Pro Dual mini packs phenomenal performance into a small... Read more
Clearance 13-inch Retina MacBook Pros availab...
B&H Photo has clearance 2015 13″ Retina Apple MacBook Pros available for up to $200 off original MSRP. Shipping is free, and B&H charges NY tax only: - 13″ 2.7GHz/128GB Retina MacBook Pro: $... Read more
Roundup of 2016 13-inch 2.0GHz MacBook Pro sa...
B&H has the non-Touch Bar 13″ MacBook Pros in stock today for $50-$100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.0GHz MacBook Pro Space Gray (MLL42LL/A): $1449 $... Read more
New 13-inch 2.0GHz Space Gray MacBook Pro in...
Adorama has the new 13″ 2.0GHz Space Gray MacBook Pro (non-Touch Bar, MLL42LL/A) in stock for $1499 including a free 3-year AppleCare Protection Plan. Shipping is free, and Adorama charges sales tax... Read more
Finnair Adopts iOS Enterprise iPad Apps from...
Finnair and IBM have announced a first-of-its-kind agreement to utilize iOS enterprise apps from IBM to support the airline’s overall digital transformation. Finnair is focused on Asia-Europe traffic... Read more
Tech21 Launches Evo Go iPhone 7 Case Availabl...
Tech21 has announced the launch of the Evo Go case for Apple iPhone 7 and iPhone 7 Plus, exclusively at T-Mobile. Available online and at participating T-Mobile stores nationwide, Evo Go cases start... Read more
Apple Turns (RED) with More Ways to Join the...
In recognition of World AIDS Day, Apple is offering more ways than ever for customers to join (RED) in its mission to create an AIDS-free generation. Apple is the worlds largest corporate contributor... Read more

Jobs Board

*Apple* Retail - Multiple Positions- Kansas...
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- Chicago...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Hardware Design Validation Engineer - *Apple...
The Apple Watch team is looking for a Hardware Design Validation Engineer. This person will be part of the Apple Watch hardware team with responsibilities for Read more
SW Engineer *Apple* TV Frameworks - Apple I...
The Apple TV team is looking for a software...create features that reflect the look and feel of Apple TV. Description: Were looking for someone who is Read more
*Apple* Retail - Multiple Positions- Greenwi...
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
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.