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

Firetask Pro 4.2.2 - Innovative task man...
Firetask Pro uniquely combines the advantages of classical priority-and-due-date-based task management with GTD. Stay focused and on top of your commitments - Firetask Pro's "Today" view shows all... Read more
Bookends 13.4.3 - Reference management a...
Bookends is a full-featured bibliography/reference and information-management system for students and professionals. Bookends uses the cloud to sync reference libraries on all the Macs you use.... Read more
LibreOffice 6.4.5.2 - Free, open-source...
LibreOffice is an office suite (word processor, spreadsheet, presentations, drawing tool) compatible with other major office suites. The Document Foundation is coordinating development and... Read more
Thunderbird 68.10.0 - Email client from...
As of July 2012, Thunderbird has transitioned to a new governance model, with new features being developed by the broader free software and open source community, and security fixes and improvements... Read more
Firefox 78.0.1 - 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
BetterTouchTool 3.389 - Customize multi-...
BetterTouchTool adds many new, fully customizable gestures to the Magic Mouse, Multi-Touch MacBook trackpad, and Magic Trackpad. These gestures are customizable: Magic Mouse: Pinch in / out (zoom)... Read more
Slack 4.7.0 - Collaborative communicatio...
Slack brings team communication and collaboration into one place so you can get more work done, whether you belong to a large enterprise or a small business. Check off your to-do list and move your... Read more
OsiriX Lite 11.0.3 - 3D medical image pr...
OsiriX Lite is an image processing software dedicated to DICOM images (".dcm" / ".DCM" extension) produced by medical equipment (MRI, CT, PET, PET-CT, ...) and confocal microscopy (LSM and BioRAD-PIC... Read more
Wireshark 3.2.5 - Network protocol analy...
Wireshark is one of the world's foremost network protocol analyzers, and is the standard in many parts of the industry. It is the continuation of a project that started in 1998. Hundreds of... Read more
Dabble 1.6.1 - Organize your manuscript,...
Dabble organizes your manuscript, story notes, and plot. Dabble simplifies the story, leaving more room in your brain to create, which is what being a writer is really about. Organize your story.... Read more

Latest Forum Discussions

See All

Pokemon Go's July Community Day wil...
Pokemon Go developers have announced the details concerning the upcoming Gastly Community Day. This particular event was selected by the players of the game after the Gas Pokemon came in second place after a poll that decided which Pokemon would... | Read more »
Clash Royale: The Road to Legendary Aren...
Supercell recently celebrated its 10th anniversary and their best title, Clash Royale, is as good as it's ever been. Even for lapsed players, returning to the game is as easy as can be. If you want to join us in picking the game back up, we've put... | Read more »
Detective Di is a point-and-click murder...
Detective Di is a point-and-click murder mystery set in Tang Dynasty-era China. You'll take on the role of China's best-known investigator, Di Renjie, as he solves a series of grisly murders that will ultimately lead him on a collision course with... | Read more »
Dissidia Final Fantasy Opera Omnia is se...
Dissidia Final Fantasy Opera Omnia, one of Square Enix's many popular mobile RPGs, has announced a plethora of in-game events that are set to take place over the summer. This will include several rewards, Free Multi Draws and more. [Read more] | Read more »
Sphaze is a neat-looking puzzler where y...
Sphaze is a neat-looking puzzler where you'll work to guide robots through increasingly elaborate mazes. It's set in a visually distinct world that's equal parts fantasy and sci-fi, and it's finally launched today for iOS and Android devices. [... | Read more »
Apple Arcade is in trouble
Yesterday, Bloomberg reported that Apple is disappointed in the performance of Apple Arcade and will be shifting their approach to the service by focusing on games that can retain subscribers and canceling other upcoming releases that don't fit... | Read more »
Pixel Petz, an inventive platform for de...
Pixel Petz has built up a sizeable player base thanks to its layered, easy-to-understand creative tools and friendly social experience. It revolves around designing, trading, and playing with a unique collection of pixel art pets, and it's out now... | Read more »
The King of Fighters Allstar's late...
The King of Fighters ALLSTAR, Netmarble's popular action RPG, has once again been updated with a plethora of new content. This includes battle cards, events and 21 new fighters, which increases the already sizeable roster even more. [Read more] | Read more »
Romancing SaGa Re;univerSe, the mobile s...
Square Enix latest mobile spin-off Romancing SaGa Re;univerSe is available now globally for both iOS and Android. It initially launched in Japan back in 2018 where it's proven to be incredibly popular, so now folks in the West can finally see what... | Read more »
Away: Journey to the Unexpected is a sto...
Away: Journey to the Unexpected looks really quite lovely. Stylish, cute, and clearly heavily inspired by Japanese animation, it's amongst the best-looking mobile games on the horizon. Developed by a two-person team, this story-driven rogue-lite... | Read more »

Price Scanner via MacPrices.net

July 4th Sale: Woot offers wide range of Macs...
Amazon-owned Woot is blowing out a wide range of Apple Macs and iPads for July 4th staring at $279 and ranging up to just over $1000. Models vary from older iPads and 11″ MacBook Airs to some newer... Read more
Apple Pro Display XDR with Nano-Texture Glass...
Abt Electronics has Apple’s new 32″ Pro Display XDR model with the nano-texture glass in stock and on sale today for up to $144 off MSRP. Shipping is free: – Pro Display XDR (nano-texture glass): $... Read more
New 2020 Mac mini on sale for up to $100 off...
Amazon has Apple’s new 2020 Mac minis on sale today for $40-$100 off MSRP with prices starting at $759. Shipping is free: – 2020 4-Core Mac mini: $759 $40 off MSRP – 2020 6-Core Mac mini: $998.99 $... Read more
July 4th Sale: $100 off every 2020 13″ MacBoo...
Apple resellers have new 2020 13″ MacBook Airs on sale for $100 off Apple’s MSRP as part of their July 4th sales. Starting at $899, these are the cheapest new 2020 MacBooks for sale anywhere: (1) B... Read more
This hidden deal on Apple’s site can save you...
Are you a local, state, or federal government employee? If so, Apple offers special government pricing on their products, including AirPods, for you as well as immediate family members. Here’s how... Read more
Apple Watch Series 3 models on sale for new l...
Amazon has Apple Watch Series 3 GPS models on sale for $30 off MSRP, starting at only $169. Their prices are the lowest available for these models from any Apple reseller. Choose Amazon as the seller... Read more
Deal Alert! Get these refurbished 2018 13″ Ma...
Apple has restocked and lowered prices on select Certified Refurbished 2018 13″ MacBook Airs, starting at only $679. Each MacBook features a new outer case, comes with a standard Apple one-year... Read more
July 4th Sale: 13″ 2.0GHz MacBook Pros for $2...
B&H Photo has new 2020 13″ 2.0GHz MacBook Pros on sale for $200 off Apple’s MSRP as part of their July 4th sale. Prices start at $1599. These are the same MacBook Pros sold by Apple in their... Read more
July 1 only: $100 off Apple iPhone 11, 11 Pro...
Boost Mobile is offering Apple iPhone 11, 11 Pro, and iPhone 11 Pro Max models for $100 off MSRP with service. Their discount reduces the cost of an iPhone 11/64GB to $599, iPhone 11 Pro to $899 for... Read more
Apple offers $50-$100 Education discount on i...
Purchase a new 12.9″ or 11″ iPad Pro at Apple using your Education discount, and Apple will take $50-$100 off their MSRP. All teachers, students, and staff of any educational institution with a .edu... Read more

Jobs Board

Operating Room Assistant, *Apple* Hill Surg...
Operating Room Assistant, Apple Hill Surgical Center - Full Time, Day Shift, Monday - Saturday availability required Tracking Code 62363 Job Description Operating Read more
Perioperative RN - ( *Apple* Hill Surgical C...
Perioperative RN - ( Apple Hill Surgical Center) Tracking Code 60593 Job Description Monday - Friday - Full Time Days Possible Saturdays General Summary: Under the Read more
Product Manager, *Apple* Commercial Sales -...
Product Manager, Apple Commercial Sales Austin, TX, US Requisition Number:77652 As an Apple Product Manager for the Commercial Sales team at Insight, you Read more
*Apple* Mac Product Engineer - Barclays (Uni...
Apple Mac EngineerWhippany, NJ Support the development and delivery of solutions, products, and capabilities into the Barclays environment working across technical Read more
Blue *Apple* Cafe Student Worker - Pennsylv...
…enhance your work experience. Student positions are available at the Blue Apple Cafe. Employee meal discount during working hours. Duties include food preparation, Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.