Spring 91 - Letters
I encountered a technical error in the Macintosh Q & A section in the latest issue of develop . The
question was: "Is the maximum size for global and local data still 32K?" The answer stated that the
32K limit for local (stack) data "is basically due to the Motorola processor architecture." As stated in
the answer, the LINK instruction is limited to a 16-bit offset. Unstated in the answer is that the
compiler can easily work around this limitation. Suppose your program declares 50K bytes of local
data. The compiler should generate a LINK instruction for the first 32K bytes and then adjust the
stack for the remaining 18K bytes needed by the routine. If the program is compiled specifically for
the 68020 or 68030, the compiler can issue a LINKL (link long) instruction, which allows a full 32-
Thanks for the clarification. You're absolutely right, but of course for most of us it doesn't make any difference;
we don't write our compilers, we're slaves to them. I guess the answer should have read "is basically due to the
way that current compilers handle local data." All you aspiring compiler writers, take note.
After receiving Gorillas in the Disc (Developer CD Series Volume VI) a few months ago, I checked out
the electronic versions of the develop issues that we did not have in hardcopy, and came across
something that prompted me to write. I was reading the letters in develop Issue 2 (April 1990) and
saw a letter and response in which you mentioned the "ever-popular audio track" from the develop CD.
Because we are an Apple Partner, our copy of develop contains a card telling us that Developer
Essentials will be included in a folder on our Developer CD Series disc. Imagine my disappointment
when I realized that the disc Apple Partners received contained no audio track. What a crime to
deprive all us Partners of such a bonus! Please tell your people that Partners want their audio!
The Developer CD Series disc contains a superset of what's on the disc that's bound into develop (now called
the Developer Essentials disc). Volume III of the Developer CD Series ("A Disc Called Wanda") corresponds
to develop Issue 2 and does indeed contain the ever-popular audio track, as part of the CD Audio Toolkit
demo. Were you looking for an audio track on the latest Developer CD Series disc? If so, you would in fact not
find one there; there wasn't one on the corresponding Developer Essentials disc, either. Rest assured that we
won't deprive Apple Partners of any of the goodies we provide on the Developer Essentials disc!
First let me say that develop is great!
I read on page 5 of the latest issue that your group is now responsible for the Developer CD Series .
Gorillas in the Disc is a bit of a disappointment. Not a lot of really new stuff on it. That's not your
fault, I know. There must be neat stuff floating around in Apple somewhere!
Someone decided that the Q & A Stack should contain both Macintosh and Apple II GS stuff. Boo,
hiss! I tend to read through that stack looking for stuff I don't know, before I know I need to know
it! I was really confused by things that I had never heard of on the Macintosh before, only to find
they were on the Apple IIGS! Arrggh! Can you please separate the II GS stuff and the Macintosh stuff
into two stacks? And can you please go back to the format of putting dots beside the new stuff?
The X Ref stuff is kinda neat. Can't wait for 7.0 aliasing!
Thanks a lot for your letter and your words of encouragement. My group contributes to the Developer CD
Series, but we're not actually responsible for it. Besides adding more new "neat" stuff, is there anything we
could do to improve the disc? We're always looking for suggestions!Sorry to hear that adding Apple
IIGS stuff to the Q & A stack confused you so much (but I'm awfully glad to
hear that you're browsing the Q & A stack!). We put the II GS info in the stack hoping that Macintosh
developers would see how similar the two toolboxes are and perhaps get some extra mileage from their work by
porting their Macintosh application to the IIGS. It sounds like it's more confusing than helpful, so we'll
reevaluate our decision. What do the rest of you think about combining II GS and Macintosh information in
In reply to your request for dots: The latest Q & A Stack has been reworked so much it's practically all new,
but in the future you can expect to once again see dots beside new material. Also note that, starting with the
latest stack, each card will show the date of the last modification.
Just a quick note to congratulate you and your staff on another fine issue of develop (and in the
hopes that I won't see a survey). I read it cover to cover, and thoroughly enjoyed it, especially the
Macintosh Q & A. I kept turning the page expecting to have seen the last question answered, but lo
and behold, there were more questions. It was better than Jeopardy. You really outdid yourselves!
Keep up the wonderful work, and please consider starting a new column: a soap opera about the
By the way, whose nose is lighting up the cover?
--Robert H. Zakon
Thanks for the letter. If we ever do a survey (and my boss has been pushing me to do one ever since Issue 2
came out), I'll make sure that the surveyors know you're officially exempt.
The nose on the cover belongs to Cleo Huggins, who has done all our covers and nose what she's doing.
COMMENTS We welcome timely letters to the editors, especially from readers
reacting to articles that we publish in develop . Letters should
be addressed to Caroline Rose (or, if technical, to Dave Johnson) at Apple Computer, Inc., 20525 Mariani Avenue, M/S 75-
2B, Cupertino, CA 95014 (AppleLink: CRose or Johnson.DK).
All letters should include name and company name as well as address and phone number. Letters may be excerpted or edited
for clarity (or to make them look like they say what we wish they did). *