Aug 86 Letters
Volume Number: 2
Issue Number: 8
Column Tag: Letters
Source Code Disk Subscription?
C.A. Weber
San Francisco, CA
Keep up the good work!
Suggestions: a) How about a subscription service for source code disks! b) How
about an on-line forum for distributing source code, questions to authors and Prof.
Mac, etc. [a) What a great idea; watch for an anouncement soon! b) That is what the
Mousehole is for. We don't have the resources for a national board, although the GEM
BBS system has contacted us about placing MacTutor's source code disks on their board
and charging access so we get paid for them. We are looking into that proposal and any
opinions would be welcome. We are somewhat leary of the disks becoming public domain
and the small but important revenue source to MacTutor drying up. -Ed.]
Best of MacTutor
David York
Neusass, Germany
In the April Mail Order Store, you advised that your book "Best of MacTutor
would be coming "next month". I went through the May issue and did not find it. Is the
book available? [Keep holding your breath, I'm working night and day on it.
Meanwhile, we have tons of back issues of every issue except vol. 1 number 6. -Ed.]
Snooping in the Operating System
Russel Hobbie
St. Paul, MN
I am a scientific programmer who is enjoying my Mac and MacTutor very much.
One thing which is not clear to me: if I want to start snooping around in the operating
system, should I get MacNosy, TMON, or both? [Both are a must, but Nosy is specific to
the problem of uncovering ROM mysteries. -Ed.]
New Macs:Old Macs
Gary Linford
Los Altos, CA
I have noticed several articles on the new file system HFS for which I am
pleased, since I have just upgraded one of my Macs to a MacPlus. However, when Apple
releases the second generation Mac (68020 CPU, open bus, wide monitor screen, etc.),
I hope MacTutor articles will continue to be valuable for programming on the old Mac.
My current concern is for development software and the new MacPlus. I have a
considerable investment in development software which is of little value on the
MacPlus. How long will MacPlus owners have to wait , and how much will it cost to
upgrade to the new versions which are HFS compatible? [Most products have now
achieved some level of HFS compatability, and generally, the HFS bugs have been
released at little or no cost to registered owners. MacTutor has encouraged Apple to
discuss ways to standardize the problem of how a program finds a file without help
from the user's standard file dialog. Right now, everyone is using their own algorithm
or method of finding program dependent files and the result is to destroy the symmetry
of the user interface between applications. We have talked to Apple about this, and they
are organizing a group to collect recommendations on an informal basis to present some
of the better approaches to the problem. -Ed.]
Stolen from Apple Computer, Part II
Steve Jasik
Menlo Park, CA
More notes on the "stolen from Apple Computer" Icon. I originally discovered the
code with Macsbug in Dec 84 when I was searching for $60FE instructions (BRA *) in
ROM. At that time I noticed that the code was dead (not referenced by any other routine
in the ROM), but did not try to execute it. A few weeks after that I had the opportunity
to meet with Andy Hertzfeld, and discussed Apple's paranoia over other manufacturer's
stealing their ROM code. He pointed out that they had left some visible copyright
notices in the ROM along with some secret notices. He said that it was possible for an
Apple programmer to test if the ROM in a machine was "stolen from Apple" by going up
to the Mac and typing in some commands. He did not explain to me the meaning of the
code I had discovered. Some months later Duane Maxwell of Levco pointed out to me the
effects of executing the code, and I posted the info on the Nosy SIG on Delphi and other
places.
There are a number of points to be learned from this particular example. I
believe the code first came to my attention in Nosy when I had to convert it from Data to
Code during Review data. This was necessary because it was unreferenced. The other
thing that makes this code easy to find is that it ends with a "BRA *" which is unusual.
So if your going to protect your code with secret messages, you should conditionally
branch to it from legimate code so that a flow analyzer does not pick it out as dead code,
and do not terminate it with a "BRA *", which can be found with a simple Hex search.
[Gee, Steve, don't teach 'em how to defeat your program! Watch for Steve's new and
improved Nosy at the Boston Expo this month. He's got some great debugging tools
coming our way! -Ed.]
Us Intermediate Programmers
Steven Brodie
Philadelphia PN
You folks put out a very informative publication; however, I wonder if it would
be possible for you to cater a bit more to the beginning to intermediate programmer. I
realize that those subscribers who are hardcore programmers would not appreciate
this much, but when publications like Macworld, Macazine, MacUser, or A+ run
tutorials, the language they use is usually BASIC, and they usually write about the most
simplistic programming techniques. Perhaps you could provide the happy medium-not
in every column-but maybe in a single column. [Look at the "Keyboard Sleuth" article
in this issue, which presents both a useful utility and a very nice TML Pascal shell
from which more powerful programs can be developed. -Ed.]
How to flatten HFS
Serge Froment
Canada
Please renew my subscription for one year. Keep on doing good work! By the
way, I would like to know how to scan all files of an HFS volume in Pascal to print a
complete directory of my DataFrame hard disk. I use TML Pascal. Thanks! [So would a
lot of developers like to know this so they can find their files! SeeTom Taylor's very
good Modula-2 article from last month's issue (July) on how to create a path name for
HFS. In that article, he alludes to the various data structures that you can use to do a
tree search through the directory list to build a data base of all the file names. -Ed.]
Manx Has its HFS Act Together
David Suess
Mesa, AZ
I thing that your magazine is the best available for showing how to program the
Mac. One item you might like to know is that Manx Software is shipping version 1.06H,
which is supposed to support the full HFS system, e specially in terms of using the full
800K storage available for the DSDD floppies; 1.06G, would only recognize 400K.
Source Code For Sale
Wayne Rod
Tucson, AZ
I see a real and current need for interested parties to have complete access to
useful information which helps stimulate their programming and problem solving
abilities. As a result, I am selling source code for an intelligent linker/assembler, text
editor and macro preprocessor for the back. I even have a Object C preprocessor. This
source code is very reasonable, only $65 for the assembler/linker and $50 for the
editor. Please notify your readers about our source code products. [You can contact
Wayne at the WSM group in Tucson, AZ at (602)-298-7910. Anyone selling
sophisticated source code for those prices should rate a phone call! -Ed.]
Thanks for MacTutor
David Wilson
Palo Alto, CA
Thank you for your prompt response in publishing my article about resource
formats. For the last year, I have been telling everyone to buy MacTutor. Now, I'll also
start recommending that they submit articles to you. I find MacTutor invaluable, and
feel that you are doing a great job. I have a number of other articles in mind to submit.
All I need is some free time... where have we all heard that before? [ Thank you. In the
publishing business, you can never have too many articles...-Ed]
Wants TML 3-D Graphics Help
Lou Gallo
Flushing, NY
Please send me the 800K Utility II Disk and the source code for Mike Morton's
famous "DissBits" routines. I'd like to see more TML Pascal articles. Finally we can
have our cake and eat it too! It's great to be able to move from IM to the editor without
translating. To me it feels like it's the only language for the Mac. (You probably hear
that from every language's corner.) Oh, by the way, how about an article on those 3D
graphics unit included with TML? Those procs look wierd! There's no help on them
from TML or IM. [You should love this issue, since, after a recent drought of good TML
articles, we have several good items this month. Perhaps Tom Leonard and his people
can include some 3D documentation in an up-coming article in the series they are doing
for us on their examples disk, a new product which features definition proc routines.
-Ed.]
Mac Plus Glitch?
Frank Alviani
Waukegan, Ill
In going over Mike Schuster's fun little article on pop-up menus in the
December 1985 issue of MacTutor, I noticed a small problem with the code. The menu is
not drawn with the code as listed; it seems that until the sizeMsg is passed to the Menu
Manager, a menu does not have a meaningful size. The fix is rather simple: add the
following line:
MenuDefProc(mSizeMsg, theMenu, &menuRect, &nilPt, & whichItem);
after the call to WaitMouseUp() that starts the PopUPSelect. This may be due to
the fact I am running this on a Mac Plus, yet another compatibility glitch.