TweetFollow Us on Twitter

Apr 86 Letters
Volume Number:2
Issue Number:4
Column Tag:Letters

Letters

Stolen From a Mac?

Erik Westra

Wellington, New Zealand

Your magazine is absolutely fantastic. I find that I can use something from every artical, even though I work mostly in assembler. I hope that the "Electrical Mac" column continues; it's got just the type of info that you can't normally get hold of.

Here's something you might be interested in. While I was poking about in the Mac's ROM, I took a look at the bit of code Steve Jasik mentioned on page 48 of your May 1985 issue. Steve said that the code blasts 32 long words into RAM and then hangs. This is the code he was talking about (on a 512K Mac):

40AD30: LEA $40AD40,A0
 MOVEQ  #$18,D1
40AD36: MOVE.L (40)+,(A1)
 ADDA.W D0,A1
 DBRA D1,$40AD36
 BRA  *-02

Looking at this, I thought that this might be the code that displays the "sad Macintosh" icon on the screen if the system bombs while booting. I displayed the 32 long words at $40AD40 as an icon using a program I'd writen in Kriya's NEON language, and look what I found (displayed at twice it's size):

Maybe the code is called by the RAM based operating system if it finds it's using funny hardware (eg, in a Mac lookalike).

[Our Forth editor, Jörg Langowski, recently paid us a visit here in Placentia while visiting from France, and I showed him Mr. Westra's letter. He was most intrigued and promtly wrote this little stolen icon finder program in Mach 1, the subject of his Threaded Code column this month. The icon is shown at twice it's normal size by this program. Note that the location of this code is different in the new ROMS! A sincere thank you Erik, for sharing this with your US friends. To my knowledge, this has never been revealed! -Ed.]

( demo to get the stolen Apple icon out of the ROM )
( c ) ( J. Langowski 1986 for MacTutor )
( start address of the icon is at $40E132, on a Mac Plus)
( and at $40AD40 on a 512K Mac, found with NOSY 2.0)

hex
variable icon   variable icnrect 4 vallot
40e132 icon !
00800080 icnrect ! 00c000c0 icnrect 4 + ! ( use double size )

: stolen icnrect icon call ploticon ; 
   ( don't know why to use pointer instead of handle for ICON )

Feature Articles?

Paul Devey

Ottawa, Ontario

Mactutor is the best Journal I have seen anywhere for any price. I have waited for years for a journal of your calibur. Please sign me up for a one year subscription as well as all of the back issues. How about sometimes having a feature section or feature issues on different topics such as graphics, sound, I/O etc. Keep up the great work. The only place you should be able to find PHLUFF is between your toes. [This month we feature desk accessories! -Ed.]

Abstract Wanted

William T. Cox

Madison, Wi.

Have you considered offering a subscription to source disks? I have no idea what your demand is, but ( based on the last year) I believe that many people would be intersted. Have you considered offering an index/abstract list for volume 1? A Microsoft File data disk would be a useful offering. A brief abstract or keyord list could be included with each article record. Thanks for a fine magazine! [Maybe the folks at MacBriefs would make us one. -Ed]

Likes Fortran

John Fineout

Duncanville, Tx

Enclosed is my payment for 1986 MacTutor subscription. I depend on your publication heavily to learn insights into programing the Macintosh. I am using Mac Fortran 2.1 forom Microsoft and Macintosh Pascal. I have missed the articles on Fortran in the alast few issues. I have ported several progams from an DEC VAX 11/750 over to the Macintosh with very little problem. I am interested to learn more on how to create a Macintosh environment for input and output for such routines. Other unknowns are how to make use of the keypad and detect tab and enter as a line terminator.

The following Mac Fortran program can be used in substitution for the VAX Fortran time and date system call. It can be made into a subroutine that returns the 23 character time and date sring similar to the VAX. [Note: code below is re-typed from a letter, not pasted from source code as we normally do, so beware. -Ed.]

 Program Time_Date
 Character Months(12)*3,APM*3,datetime*23
 Integer Seconds,MM,DD,YY,L,M
 Real Hours
 Data Months/'JAN','FEB','MAR','APR','MAY','JUN', 
2      'JUL','AUG', 'SEP',''OCT','NOV','DEC'/
 Call Time(Seconds)
 Hours = Seconds/86400.0*24.0
 L = AINT(Hours)
 Mins = (Hours - L)* 60.0
 if (L .gt. 12) then
 APM = ' pm'  
 L = L - 12
 Else
 APM = ' am'
 End if
 Call Date(MM,DD,YY)

 Write(datetime,fmt='I2,A,I2.2,A3,
2     a6,I2,a,A3,a,I2')  L,char(58),Mins,APM,
2     ' Date ',DD,char(45), Months(MM),char(45),YY
 Write (9,100)datetime
100Format ('Time is now ',a23)
 pause
 stop
 end

Maybe this will be helpful to someone. Please deep the Fortran articles coming. [What would be the most help is to convince Microsoft to support and upgrade Fortran to run under HFS on the Mac Plus before 1988, and to make their linker more MDS compatible and bug free. A decent Mac interface would be nice also. And don't forget to mention finishing the parameter glue file support and documentation! -Ed.]

Notes on Basic

Gary Voth

Ontario, Ca

I want to say that I enjy Dave Kelly's fine columns on BASIC programming. BASIC is a favorite language of mine, despite its limitations. I love the interactive pampering that only an interpreted language can give.

However, I spotted an error or two in the January article on using scroll bars from BASIC. I'd like to share the corrections with your readers.

On page 25 the author notes a problem using the BASIC function DEFINT a-z with library calls. To prevent errors from occurring when library routines care called, he recommends defining integer arguments individually (by using the % sign) instead of using the DEFINT statement. Actually, this does prevent the errors, but only by accident!

The reason that calling a bibrary routine creates an error after a DEFINT statement has to do with the way the routines are accessed by BASIC. When a programmer invokes a library routine, such a

CALL  DisposeScroll(ScrID%)

BASIC actually creates a data structure in memory that contains the routine's object code and (in our example) assigns the starting address the variable name "DisposeScroll." Since BASIC's interger data type is 16 bits long, and Macintosh memory locations require at least 24 bits to represent, an error is generated if the variable "DisposeScroll" is defined as an interger (as would be the case after a DEFINT statement)!

It is easy to work around this limitation, however, by designating our llibrary routine names as single-precision (32 bit) variables using the ! sign. This is done in the form below:

            DEFINT a-z
            Call DisposeScroll!(scrID)

Alternatively, you can use the form:

          DEFINT a-z
             DisposeScroll! ScrID

Note that this is essentially the same thing as calling an assembly language routine that has been appended to BASIC the old fashioned way-by POKE-ing it into an array. The array's starting address, as returned by the VARPTR function, can never be forced into an integer:

          DEFINT a-z
             ...
             DisposeScroll!=VARPTR(AsmArray(0)
          CALL DisposeScroll!(ScrID) 

One more note: In the question and answer section the author discusses ways to clear parts of the screen individually without using the CLS function. (By "screen" we of course mean window.) One simple way of doing this that wasn't mentioned is to "paint" with white. Use the Quickdraw call FILLRECT or the BASIC LINE statement to draw a rectangle of white pixels over the section of the window that neds to be erased. For example:

Black% = 33
White% =30
...
LINE(50,50)-(100,100),White%,bf

will erase a section of the current output window 50 pixels square. Of course, the current penmode shold be the default COPY mode. If it has been changed the programmer should restore it with a CALL PENMODE(8) statement.

HFS and Dollars & $ense

Terry A. Ward

Cedar Falls, La

I read with interest the status of commecial software with the HFS file system (vol.2 #1). I noticed that Dollars & $ense is noted as bombing with an insufficient memory message. A quick fix that has worked for me is to reduce the number of desk accessories in the system. By reducing the size of desk accessories from 22,730 bytes to 12,926 I am able to use the product with no problems.

Keep up the great work with MacTutor!

The Max Board!

Mike Carlton

Berkeley, Ca

In the Dec. 1985 issue you have included one of my posts on the MouseHole, concerning the MacMemory board. I would like to make a few corrections now that some new information has come to light. I spoke to some of the MacMemory people at the MacWorld conventionin San Francisco and the told me that the TheMax is NOT compatible with the new ROMs from apple. However, they want to be fair to their customers so they are offering an upgrade, at their cost, to TheMax2. This new board comes; with 2 meg. of RAM and sockets for expansion to 4 meg! All you ned to do is plug in 16 1 meg. chips and you have a 4 meg. Mac. The new board is compatible with the new ROMs; however, if you use the new ROMs, you lose the non-volitable RAM disk.

Anyone with TheMax should contact their dealer. MacMemory is selling the boards to the dealers at cost and asking the dealers to do the upgrade (just a board swap) at no profit. They said prices shold be around $150, but this wasn't finalized.

Friend of MacTutor

Doyle B. Myers

Seattle, Wa

I heard about your "setback" - the loss of your equipment and records from Steve Brecher, my Compu Serve buddy. He suggested that subscribing to MacTutor would be a nice way to help out, and you've got such an impressive reputation with all my fellow developers that I have no problems at all with that. Good luck and keep up the good work! [Thank you very much and to all of our friends and supporters who have expressed their appreciation for our continued publication. -Ed.]

Renewal to ease the pain

Rod Paine

Purcellville, Va

Sorry to learn of your robbery at MacTutor, I hope you're able to put things back together without too much of a loss being sustained.

I know that every little bit can help right now, so I've enclosed a subscription renewal... I think mine is up about August, but in any ccase please add this onto it.

While we only met briefly at the Boston Mac Expo and we'd never be able to pick each other out in a crowd, what you are poviding the readers of MacTutor does maake you stand out... and I'm pleased to be a part of the readership and what MacTutor stands for. [Spoken like a true old-timer! Thanks very much. -Ed.]

Share your technical thoughts on Mac snooping and programming. Write to MacTutor today!

 

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.