Tricks of the Mac Game Programming Gurus/TricksOfTheMacGameProgrammingGurus.iso/Information/CSMP Digest/volume 1/csmp-v1-184.txt

Text File | 1994-12-08 | 43.0 KB | 1,145 lines | [TEXT/R*ch]

C.S.M.P. Digest             Thu, 15 Oct 92       Volume 1 : Issue 184

Today's Topics:

    System Extension sample source wanted!!
    PLstrcmp?? Do the right thing!
    IM 1-7  vs New: FILES, PROCESSES, MEMORY Books
    STUFFIT FORMAT
    Problem writing INIT/cdev
    A/ROSE
    Best text compression?
    How do you launch a Control Panel?
    Top byte of 24-bit offscreen gworld?



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-------------------------------------------------------

From: Minh Lang <[e-mail]>
Subject: System Extension sample source wanted!!
Organization: Jet propulsion Laboratory
Date: Tue, 28 Jul 1992 15:43:57 GMT

I am looking for some sample source for writing System Extension.
I would appreciate any pointer or info (ftp sites, books etc...).
Thanks.
 == Minh ==

+++++++++++++++++++++++++++

From: [e-mail] (Heng Chiang)
Organization: Monash University
Date: Wed, 29 Jul 1992 05:03:58 GMT

[e-mail] (Minh Lang) writes:
: I am looking for some sample source for writing System Extension.
: I would appreciate any pointer or info (ftp sites, books etc...).
: Thanks.
:  == Minh ==

Me TOO!  I have found a lot of source code for general applications
but I haven't seen any for control panels / extensions.  I would
really like to know how people actually start writing extensions (INIT)
with the horrible lack of documentation.
  I would rather prefer email, because I generally do not check this
particular group.  Thanks!

    Heng.

- --
Heng Chiang                    Internet: [e-mail]
STRESS - The confusion created when      [e-mail]
the mind overrides the body's urge       [e-mail]
to choke the living daylight out of          RULE 1 - The female is always
some deserving people. - Unknown                      *right*?  - Somebody

+++++++++++++++++++++++++++

From: [e-mail] (Carl W. Haynes III)
Date: 29 Jul 92 09:11:58 GMT
Organization: Purdue University

In article <[e-mail]> [e-mail] (Heng Chiang) writes:
>[e-mail] (Minh Lang) writes:
>: I am looking for some sample source for writing System Extension.
>Me TOO!  I have found a lot of source code for general applications
>but I haven't seen any for control panels / extensions.  I would
>really like to know how people actually start writing extensions (INIT)
>with the horrible lack of documentation.

The best piece of documentation I've seen on writing INITs was an article
by Eric Shapiro that I pulled off of AOL called "Writing INITs in Think C".
I'm not sure if it's available in any of the archives. If you can't find
it and don't have access to AOL let me know and I'll e-mail a copy to
any one who wants it. This article has the best INIT shell I've seen.

The second edition of Macintosh Programming Secrets also has info on writing
inits, including patching traps. I personally think that someone should write
a whole book on low-level stuff like drivers and inits.

If your interested in communications, Programming with AppleTalk has an
example of an INIT.

The Macintosh C Programming Primer Vol II has an example of an INIT,
although it does not patch any traps which is usually what you want to
do when you write an INIT. However, it has a good example of a cdev.

Personally, I learned how to write INITs by deciding on something that I
wanted to do and posting lots of questions. Like most aspects of Mac
programming, writing INIT's has a pretty steep learning curve, but the
rewards definately are worth the effort.

- --
Carl W. Haynes III
Haynes Consulting Services        ||  [e-mail]
PO Box 2715                       ||  [e-mail]
W. Lafayette, IN 47906            ||  [e-mail]
- ----------------------------------------------------------------------
     Macintosh Programming & Consulting -- I am currently seeking
        Macintosh development contracts, available immediately.

+++++++++++++++++++++++++++

From: [e-mail] (Michael Peirce)
Date: 29 Jul 92 17:01:54 GMT
Organization: Peirce Software


In article <[e-mail]> (comp.sys.mac.programmer), [e-mail] (Heng Chiang) writes:
> [e-mail] (Minh Lang) writes:
> : I am looking for some sample source for writing System Extension.
> : I would appreciate any pointer or info (ftp sites, books etc...).
> : Thanks.
> :  == Minh ==
>
> Me TOO!  I have found a lot of source code for general applications
> but I haven't seen any for control panels / extensions.  I would
> really like to know how people actually start writing extensions (INIT)
> with the horrible lack of documentation.

The book "Programming with AppleTalk" from Addison-Wesley (and
written by me) has a complete RDEV/INIT example.  This is a
Chooser interface (the RDEV part) as well as an INIT that
installs some code into the system heap (to listen to an
AppleTalk socket).

- --  Michael Peirce      --   [e-mail]
- --  Peirce Software     --   Suite 301, 719 Hibiscus Place
- --                      --   San Jose, California USA 95117
- --  Makers of...        --   voice: [phone] fax: [phone]
- --            SMOOTHIE  --   AppleLink: peirce & America Online: AFC Peirce

+++++++++++++++++++++++++++

From: [e-mail] (Keith Rollin)
Date: 31 Jul 92 07:03:17 GMT
Organization: Taligent

In article <[e-mail]>, [e-mail] (Carl W.
Haynes III) writes:
>
> The second edition of Macintosh Programming Secrets also has info on writing
> inits, including patching traps. I personally think that someone should write
> a whole book on low-level stuff like drivers and inits.

Me, too...   :-)

- --
Keith Rollin
Phantom Programmer
Taligent, Inc.

---------------------------

From: [e-mail] (John Purlia)
Subject: PLstrcmp?? Do the right thing!
Date: 28 Jul 92 21:51:57 GMT
Organization: Qualcomm, Inc.

Has anyone else noticed the effective weirdness of PLstrcmp in MPW?  I'm
using qsort to sort a list of pascal style strings in ascending alphabetic
order.  My comparison function basically uses a PLstrcmp to test equality
of the list elements.  Here's the weird part:  PLstrcmp thinks that "Public
Folder" comes before "Public".  If I take the same data, convert each
element to C style using p2cstr, and use strcmp in my comparison function,
"Public" comes before "Public Folder" just as you would expect.

Is there a known bug in PLstrcmp (MPW 3.2) or for that matter any of the
other Pascal style string routines?  Is there a fix or am I going to have
to do the convert to C conversion all over the place?  (No, the toolbox
routine I'm using to get the data does not have a C string equivalent.)

...........................................................................
John Purlia          : My brain; not my company's brain.  My brain says...
[e-mail] :      "Just about any movie could be made better
AppleLink:  AM0470   :       if one of the characters were a vampire."
...........................................................................

+++++++++++++++++++++++++++

From: [e-mail] (Keith Rollin)
Date: 29 Jul 92 08:33:41 GMT
Organization: Taligent

In article <jpurlia-280792143857@129.46.5.45>, [e-mail] (John
Purlia) writes:
>
> Has anyone else noticed the effective weirdness of PLstrcmp in MPW?  I'm
> using qsort to sort a list of pascal style strings in ascending alphabetic
> order.  My comparison function basically uses a PLstrcmp to test equality
> of the list elements.  Here's the weird part:  PLstrcmp thinks that "Public
> Folder" comes before "Public".  If I take the same data, convert each
> element to C style using p2cstr, and use strcmp in my comparison function,
> "Public" comes before "Public Folder" just as you would expect.
>
> Is there a known bug in PLstrcmp (MPW 3.2) or for that matter any of the
> other Pascal style string routines?  Is there a fix or am I going to have
> to do the convert to C conversion all over the place?  (No, the toolbox
> routine I'm using to get the data does not have a C string equivalent.)

I don't know about PLstrcmp. If I were in your position, I'd do one of two
things:

- - Disassemble PLstrcmp and see WTF was going on.
- - Use one of the toolbox routines that compares Pascal strings (RelString,
EqualString, IUCompString, IUMagString, IUEqualString, or IUMagIDString). Here
are some notes I have on the functions (I can never keep them straight!):

    Name            Takes   Case    Diac    Returns         Trap used
    --------------  ------- -----   -----   ------------    ----------
    RelString:      Str255  spec    spec    -1, 0, 1        _RelString
    EqualString:    Str255  spec    spec    Boolean         _CmpString

    IUCompString:   Str255  TRUE    TRUE    -1, 0, 1        _Pack6,#10
    IUMagString:    Ptr/len TRUE    TRUE    -1, 0, 1        _Pack6,#10

    IUEqualString:  Str255  FALSE   FALSE   Inv. Boolean    _Pack6,#12
    IUMagIDString:  Ptr/len FALSE   FALSE   Inv. Boolean    _Pack6,#12

The Case and Diac columns refer to whether or not the functions are sensitive to
case or diacriticals. "spec" means that you can specify whether they are or not.

- --
Keith Rollin
Phantom Programmer
Taligent, Inc.

---------------------------

From: 21602MR@MSU (Mark Rosenberg)
Subject: IM 1-7  vs New: FILES, PROCESSES, MEMORY Books
Date: 26 Aug 92 14:48:45 GMT
Organization: Michigan State University

I am jumping into programming the MAC - All sources say I need IM 1, and
a few other IM vols, But Addison Wesley has come out with 3 new books:
Files, Processes, and Memory which replace the original IM books??
Do I STILL need to get IM v1 (with references to 128k MACs and LISA)
or should I get one or all of the New books??
Thanks in advance... Please respond to the net!
Mark Sartor (via Mark Rosenbergs account)

+++++++++++++++++++++++++++

From: [e-mail] (Keith Rollin)
Date: 26 Aug 92 20:12:10 GMT
Organization: Taligent

In article <[e-mail]>, 21602MR@MSU (Mark
Rosenberg) writes:
>
> I am jumping into programming the MAC - All sources say I need IM 1, and
> a few other IM vols, But Addison Wesley has come out with 3 new books:
> Files, Processes, and Memory which replace the original IM books??
> Do I STILL need to get IM v1 (with references to 128k MACs and LISA)
> or should I get one or all of the New books??

If you can wait (and have the bucks), I'd suggest getting the new books. As
you've seen, there are three now, and probably about 12 more in the wings. The
whole new suite is intended to replace the old IM I-VI, as well as many of the
technotes and sample code that DTS puts out. They are chock full of samples, and
include a lot more background and tutorial material.

The two issues with deciding to go with the new books are:

- - They aren't all out, yet.

- - They'll cost a lot more than IM I-VI. The three volumes that you mention run
$78 in the US, so figure about $300-400 for the lot (IM I-VI comes to about
$200). Of course, there may be a discount if you get all of them at once.

You also might want to consider having to deal with a new set of errors and
typos. For those of us who have gotten well used to the old IM's and know where
all the errors are, it may be disconcerting to have to deal with a new set.
Hopefully, there won't be that many (as a technical reviewer for them, I
personally guarantee absolutely no errors in Files, Processes, or Memory  :-) ).
For people who haven't dealt with IM before, this won't be as much of a problem.

- --
Keith Rollin
Phantom Programmer
Taligent, Inc.

+++++++++++++++++++++++++++

From: [e-mail] (Shawn O'Donnell)
Date: 26 Aug 92 20:40:52 GMT
Organization: M.I.T. Media Laboratory

>  Do I STILL need to get IM v1 (with references to 128k MACs and LISA)
>  or should I get one or all of the New books??

Depends on who's paying. And on how long you can wait for the 15-20
volumes that make up the rest of the new series.  But mostly on who's
paying.

+++++++++++++++++++++++++++

From: [e-mail] (Andrew Reynhout)
Organization: University of Rhode Island, Computer Science Dept.
Date: Wed, 2 Sep 1992 22:19:18 GMT

In article <[e-mail]> [e-mail] (Keith Rollin) writes:
>If you can wait (and have the bucks), I'd suggest getting the new books. As
>you've seen, there are three now, and probably about 12 more in the wings. The
>whole new suite is intended to replace the old IM I-VI, as well as many of the
>technotes and sample code that DTS puts out. They are chock full of samples,
>and include a lot more background and tutorial material.

   As an aside, are the code examples in C this time?

   Andrew

- --
   Andrew <[e-mail]>    "If you remind me of my dog,
                                    we'll probably get along"  -jane siberry
   meow

+++++++++++++++++++++++++++

From: [e-mail] (Joe Francis)
Date: 3 Sep 92 21:01:06 GMT
Organization: Dartmouth College, Hanover, NH

In article <[e-mail]>
[e-mail] (Andrew Reynhout) writes:

>As an aside, are the code examples [in the new IM series] in C this time?

No, still Pascal.  However, the "Summary" at chapter ends where they
list constants, data types, procedures, etc, now has *3* sections:
Pascal, C, and Assembly.

---------------------------

From: [e-mail] (Tim Meade)
Subject: STUFFIT FORMAT
Date: 29 Aug 92 10:32:00 GMT
Organization: The Web BBS 1-513-436-9011 6 Lines 1200 News groups 50,000 files!

I am in need of the Stuffit or Unstuffit format. Is this in the public
domain?  I want to do a conversion program and would like to be able to
directly handle these files.  Any help would be apprecitive.

Please email me at [e-mail]


                thanks....Tim


+++++++++++++++++++++++++++

From: [e-mail] (Steve Fuller)
Date: 30 Aug 92 06:03:53 GMT
Organization: Texas A&M University, College Station

In article <[e-mail]> [e-mail] (Tim Meade) writes:
>I am in need of the Stuffit or Unstuffit format. Is this in the public
>domain?  I want to do a conversion program and would like to be able to
>directly handle these files.  Any help would be apprecitive.
>

Not much chance of obtaining the new 3.0 format. HOWEVER, SD (and SL?) support
' a large number of Apple events'. Contact Aladdin for details.
[phone] or ALADDIN@Applelink

If Leonard is reading, perhaps he could provide more info. Like:
Can applications call the StuffIt Engine? or must the use the SD App?
Can the free UnStuffIt handle Apple Events? or be externally scripted?

Steve Fuller
[e-mail]

+++++++++++++++++++++++++++

From: [e-mail]
Organization: Campus Computing Sites, University of Michigan-Ann Arbor
Date: Tue, 1 Sep 1992 05:30:37 GMT

In article <[e-mail]> [e-mail] (Steve Fuller) writes:
>In article <[e-mail]> [e-mail] (Tim Meade) writes:
>>I am in need of the Stuffit or Unstuffit format. Is this in the public
>>domain?  I want to do a conversion program and would like to be able to
>>directly handle these files.  Any help would be apprecitive.
>>
>
>Not much chance of obtaining the new 3.0 format. HOWEVER, SD (and SL?) support
>' a large number of Apple events'. Contact Aladdin for details.
>[phone] or ALADDIN@Applelink
>
    Actually we license the format information to "needy" people, we also
license the StuffIt Engine for inclusion in products that wish to provide
stuffing/unstuffing capabilities. You want to call Aladdin and ask to speak
to licensing.

>If Leonard is reading, perhaps he could provide more info. Like:
>Can applications call the StuffIt Engine? or must the use the SD App?
>Can the free UnStuffIt handle Apple Events? or be externally scripted?
>
    The StuffIt Engine is still available as part of the StuffIT Deluxe
and StuffIt SpaceSaver packages, and (as mentioned above) can also be
licensed for direct inclusion in your own applications.  Also, all of
our application products (Lite, Deluxe, Expander, UnStuffIt, etc.) are all
Apple event aware and include an 'aete' resource (as per the OSA guidelines)
for describing the supported events.

- --
- -----------------------------------------------------------------------
Leonard Rosenthol          Internet: [e-mail]
Director of Advanced Technology   AppleLink: MACgician
Aladdin Systems, inc.          GEnie:     MACgician

+++++++++++++++++++++++++++

From: [e-mail] (J. Taggart Gorman)
Date: 1 Sep 92 07:35:42 GMT
Organization: Organization?  We don't need no steenking organization!


In article <[e-mail]>,
Citizen [e-mail] writes :
>    The StuffIt Engine is still available as part of the StuffIT Deluxe
>and StuffIt SpaceSaver packages, and (as mentioned above) can also be
>licensed for direct inclusion in your own applications.  Also, all of
>our application products (Lite, Deluxe, Expander, UnStuffIt, etc.) are all
>Apple event aware and include an 'aete' resource (as per the OSA guidelines)

  This message is not necessarily aimed at Leonard.

  How does one read the "aete" resource?  With a template, right?  If so,
where can I find the necessary template?  My ResEdit doesn't have it (I have to
dredge thru the resource in straight hex/char, ick!), and I don't recall seeing
it at any ftp site?  Is it in a league with BalloonWriter?  (Ie, only available
from ADPA?)

 Thanks.

|--------------------------------|    "If you were happy all of your life,
|      J. Taggart Gorman Jr.     |     you wouldn't be human - you'd be a
| [e-mail] |     game show host."
|--------------------------------|             Winona Ryder, in _Heathers_

+++++++++++++++++++++++++++

From: [e-mail] (Glen Stewart)
Date: 31 Aug 92 04:06:57 GMT
Organization: FidoNet node 1:2240/175 - The Associati, Grand Blanc MI

I have a couple programs here that examine StuffIt files.  One contains Pascal
source code.  Perhaps one of them may help.  If so, feel free to call the BBS.


- --
=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
 Glen Stewart - Internet: [e-mail]

---------------------------

From: [e-mail] (Peter Landweber)
Subject: Problem writing INIT/cdev
Date: 3 Sep 92 05:53:43 GMT
Organization: Rutgers Univ., New Brunswick, N.J.



     I am working on an INIT/cdev combination to be used under System
7, and I've run into a problem.
     At startup time, the INIT moves its resource map after the system
resource map in the linked list, and it patches CloseResFile() to
ignore the file.  The result is that my file stays open, and its
resources are always available.  This is similar to what Suitcase II
does with font suitcases.  So far everything has gone extremely well
using this technique.
     Now, I'm trying to add a "cdev".  The problem is that when the
finder opens up my file as a Control Panel, it expects my file's
resource map to be the first in the linked list.  Since the resource
map is actually at the end of the linked list, the finder crashes.

So, my questions are:
1)  Is there a way for the Finder to open up a Control Panel if the
file is already open, and its resource map is not at the front of the
linked list?
2)  Is there a way to open a file twice, with two separate resource
maps?  That way, I could still have one resource map linked after the
system resource map, and the other at the front of the linked list.
One of the maps could be read-only if necessary.

Any suggestions, answers, or solutions would be greatly appreciated.

- -- Greg Landweber  ([e-mail])

+++++++++++++++++++++++++++

From: [e-mail] (Keith Rollin)
Organization: Taligent
Date: Thu, 3 Sep 1992 20:08:55 GMT

In article <[e-mail]>,
[e-mail] (Peter Landweber) writes:
>
>
>
>      I am working on an INIT/cdev combination to be used under System
> 7, and I've run into a problem.
>      At startup time, the INIT moves its resource map after the system
> resource map in the linked list, and it patches CloseResFile() to
> ignore the file.  The result is that my file stays open, and its
> resources are always available.  This is similar to what Suitcase II
> does with font suitcases.  So far everything has gone extremely well
> using this technique.
>      Now, I'm trying to add a "cdev".  The problem is that when the
> finder opens up my file as a Control Panel, it expects my file's
> resource map to be the first in the linked list.  Since the resource
> map is actually at the end of the linked list, the finder crashes.
>
> So, my questions are:
> 1)  Is there a way for the Finder to open up a Control Panel if the
> file is already open, and its resource map is not at the front of the
> linked list?
> 2)  Is there a way to open a file twice, with two separate resource
> maps?  That way, I could still have one resource map linked after the
> system resource map, and the other at the front of the linked list.
> One of the maps could be read-only if necessary.

I have an INIT/cdev that does the same thing. However, it takes a little
different approach than yours, and it seems to work.

First, I don't patch CloseResFile() to keep my file open. Instead, at INIT time,
I install my code, remember the file I came from, and patch InitAllPacks(). I
remember my file of origin with the following routine.


static void    RememberMe()
{
    FCBPBRec    pb;
    OSErr        err;

    pb.ioCompletion = nil;
    pb.ioNamePtr = gOurName;
    pb.ioVRefNum = 0;
    pb.ioRefNum = CurResFile();
    pb.ioFCBIndx = 0;

    err = PBGetFCBInfoSync(&pb);

    gOurVRefNum = pb.ioFCBVRefNum;
    gOurDirID = pb.ioFCBParID;
}


I patch InitAllPacks() so that I can re-open my resource fork just before the
first application is run:


static pascal void    MyInitAllPacks(void)
{
    SetUpA4();

    oldInitAllPacks();

    if (gMyRefNum == 0)
        OpenAndAddMe();

    RestoreA4();
}


OpenAndAddMe() opens the resource fork and shuffles it behind the System file:


typedef struct ResourceMap{
    long        dataOffset;
    long        mapOffset;
    long        dataLength;
    long        mapLength;
    struct ResourceMap    **nextMap;
    short        refNum;
    short        attributes;
    short        typesOffset;
    short        namesOffset;
} ResourceMap, *ResMapPtr, **ResMapHandle;

static void    OpenAndAddMe()
{
    THz                currentZone;

    short            oldFile;
    short            refNum;
    ResMapHandle    current = nil;
    ResMapHandle    previous = nil;
    ResMapHandle    ourParent = nil;
    ResMapHandle    us = nil;
    ResMapHandle    system = nil;

    currentZone = GetZone();
    SetZone(SystemZone());

    oldFile = CurResFile();
    refNum = InlineHOpenResFile(gOurVRefNum, gOurDirID, gOurName, fsRdPerm);
    UseResFile(oldFile);

    if (refNum != -1) {

        current = (ResMapHandle) TopMapHndl;

        // First, find us (we should be on top)

        while ((current != nil) && ((**current).refNum != refNum)) {
            previous = current;
            current = (**current).nextMap;
        }
        if (current != nil) {
            ourParent = previous;
            us = current;
        }

        // Second, find the System

        system = (ResMapHandle) SysMapHndl;

        if ((us == nil) || (system == nil)) {
            CloseResFile(refNum);
        } else {
            if (ourParent != system) {

            //
            // Be sure to perform all these steps so that the
            // resource chain is never inconsistant or circular.
            // If that happens, debuggers like TMON will detonate.
            //
                if ((ResMapHandle) TopMapHndl == us)
                    TopMapHndl = (void*) (**us).nextMap;
                if (ourParent)
                    (**ourParent).nextMap = (**us).nextMap;
                (**us).nextMap = (**system).nextMap;
                (**system).nextMap = us;
            }
            gMyRefNum = refNum;
        }
    }
    SetZone(currentZone);
}

I've checked the resource chain with this setup, and my INIT/cdev file appears
to get opened twice when the cdev is opened.

Hope this helps,

- --
Keith Rollin
Phantom Programmer
Taligent, Inc.


---------------------------

From: [e-mail] (Alex Colvin)
Subject: A/ROSE
Date: 3 Sep 92 20:12:12 GMT
Organization: Dartmouth College, Hanover, NH

I'm looking for a realtime operating system to run on embedded 680x0s.
I'm using a macintosh as a development platform.
Someone mentioned A/ROSE as a possibility. I can't find anything
about it.
        Is it supported?
        Is it supported by MPW?
        Does it run only in a nubus slot on a macintosh, or can it
        stand alone?
    Is it any use?
        Is there someone I can call to get details?

                Alex Colvin
                603/643-7309
                [e-mail]

+++++++++++++++++++++++++++

From: [e-mail] (Richard K. Nordin)
Date: 4 Sep 92 04:20:03 GMT
Organization: Cybernetic Arts

The A/ROSE Software Kit is available from APDA (US 800-282-2732, Int'l
408 562-3910).

I could answer your other questions, but I shouldn't. But, if a
real Apple person doesn't answer them, I'll do some harrassing
on your behalf.
- --

Hud Nordin
Cybernetic Arts                [e-mail]
Post Office Box 2066           Telephone: [phone]
Sunnyvale, California 94087    Facsimile: 408.248.0416

+++++++++++++++++++++++++++

From: [e-mail] (Arnold Niedermaier)
Date: 8 Sep 1992 08:51:50 GMT
Organization: University of Karlsruhe, FRG


In article <[e-mail]>, [e-mail] (Alex Colvin) writes:
|> I'm looking for a realtime operating system to run on embedded 680x0s.
|> I'm using a macintosh as a development platform.
|> Someone mentioned A/ROSE as a possibility. I can't find anything
|> about it.
|>         Is it supported?
|>         Is it supported by MPW?
|>         Does it run only in a nubus slot on a macintosh, or can it
|>         stand alone?
|>     Is it any use?
|>         Is there someone I can call to get details?
|>
|>                 Alex Colvin
|>                 603/643-7309
|>                 [e-mail]

- --
We are using A/ROSE the Apple/Realtime Operating System Environment in our
macintosh laboratory at the institute for computer design and fault tolerance.
In our configuration A/ROSE runs on Serial NB MCP cards plugged in nubus slots
on macintosh computers. These cards are connected with Apple V24/RS232 cables and
form a distributed system.
We also use MPW as a development environment.platform. In order to run
the programs under A/ROSE you have to link some spezial libraries.
When we run a distributed application on the cards we use the Macs as
I/O devices to monitor and control the programflow. Our main interests are
to examine fault-tolerant mechanisms and fault-tolerant protocols.
Therefore we have developed a communication kernel which provides communication
promitives and a fault injection tool to trigger particular fault situations.
Until now we have implemented and tested several fault-tolerant protocols
on this system.
Our expierence with A/ROSE is the following:
    - the programs have to be implemented in C or assembler
    - there is no support for floating point operations
A/ROSE together with the Serial NB Card satisfies our application requirements
and we are going to use it in more areas.

******************************************************************************
Arnold Niedermaier                               *   Tel.:   [phone]
Universitaet Karlsruhe                           *   Fax.:   [phone]
Inst. fuer Rechnerentwurf und Fehlertoleranz     *   E-Mail: [e-mail]
Postfach 69 80                                   *
W-7500 Karlsruhe 1 Germany                       *

---------------------------

From: [e-mail] (Alan Goates)
Subject: Best text compression?
Organization: University of Denver, Dept. of Math & Comp. Sci.
Date: Thu, 3 Sep 92 21:45:18 GMT



First, thanks to everyone who answered my Notification Manager question.
(I didn't have the latest tech notes yet)
Second, does anyone know what the best published (Public Domain) algorithm is
for compressing text. And does anyone know where I could get my hands on examplesource code for said algorithm (The only one I've seen is Lempel-Ziv).
Thanks in advance,
AL

+++++++++++++++++++++++++++

From: [e-mail] (Clark Anderson)
Date: 4 Sep 92 03:54:08 GMT
Organization: Apple Computer Inc., Cupertino, CA

[e-mail] (Alan Goates) writes:



>First, thanks to everyone who answered my Notification Manager question.
>(I didn't have the latest tech notes yet)
>Second, does anyone know what the best published (Public Domain) algorithm is
>for compressing text. And does anyone know where I could get my hands on examplesource code for said algorithm (The only one I've seen is Lempel-Ziv).
>Thanks in advance,
> AL

I have gotten pretty good compression on text using
a Huffman algorithm. It's pretty easy to implement,
any standard book on compression schemes should
have it.
                           --clark
- ----------------------------------------------------------
Clark Anderson                 BellNet: 408-974-4593
Apple Computer, Inc.         AppleLink: C.ANDERSON
                              InterNet: [e-mail]
I speak only for myself...
- ----------------------------------------------------------


+++++++++++++++++++++++++++

From: [e-mail] (Keith Rollin)
Organization: Taligent
Date: Fri, 4 Sep 1992 07:07:32 GMT

In article <[e-mail]>, [e-mail] (Clark Anderson) writes:
> [e-mail] (Alan Goates) writes:
>
> >Second, does anyone know what the best published (Public Domain) algorithm is
> >for compressing text. And does anyone know where I could get my hands on
> >examplesource code for said algorithm (The only one I've seen is Lempel-Ziv).
>
> I have gotten pretty good compression on text using
> a Huffman algorithm. It's pretty easy to implement,
> any standard book on compression schemes should
> have it.

I've never tried this myself, but someone once told me that you can get really
good compression if you use a Huffman algorithm applied at the word level.
Instead of counting and ranking all of the letters in the document, count the
distinct words and treat each one like a single letter. This means that oft used
words like "the" or "MicroSoftWord5.0Sucks" will compress down to 3 or 4 bits
for the entire word.

- --
Keith Rollin
Phantom Programmer
Taligent, Inc.


+++++++++++++++++++++++++++

From: [e-mail] (Kent Sandvik)
Date: 5 Sep 92 01:42:30 GMT
Organization: Apple

In article <[e-mail]>, [e-mail] (Clark Anderson)
wrote:
> I have gotten pretty good compression on text using
> a Huffman algorithm. It's pretty easy to implement,
> any standard book on compression schemes should
> have it.

For instance the new "Algorithsm in C++" by Sedgewick has a code
snippet showing how it's done. Seems more and more authors are making
big bucks on rewriting their books with "C++" in the title.

Kent Sandvik/DTS

+++++++++++++++++++++++++++

From: [e-mail] (Jon W{tte)
Date: 7 Sep 92 10:19:45 GMT
Organization: Royal Institute of Technology, Stockholm, Sweden

> [e-mail] (Alan Goates) writes:

   Second, does anyone know what the best published (Public Domain) algorithm is
   for compressing text. And does anyone know where I could get my hands on example
   source code for said algorithm (The only one I've seen is Lempel-Ziv).

Lempel-Ziv isn't too bad (actually, that's two whole familys of
algorithms)

Source avaialble for the macintosh is LZRW-1b which is a high-
speed, LZ-77 derivative.

"Yabba" is an LZ-78 relative that also is in the public domain.

- --
Jon W{tte, [e-mail], Sweden, Phone [phone]

Help eradicate FIDO-Net <-> Usenet gateways in our time!

+++++++++++++++++++++++++++

From: [e-mail] (Glenn Stauffer)
Date: 9 Sep 92 00:31:45 GMT
Organization: Swarthmore College Computing Center

In article <[e-mail]> Jon W{tte,
[e-mail] writes:
>Source avaialble for the macintosh is LZRW-1b which is a high-
>speed, LZ-77 derivative.
>
>"Yabba" is an LZ-78 relative that also is in the public domain.
>

Does anyone have the address of an FTP site for the LZ* source?

---------------------------

From: [e-mail] (Matthew Xavier Mora)
Subject: How do you launch a Control Panel?
Date: 3 Sep 92 22:10:29 GMT
Organization: SRI International

How do you launch a control panel under system 7? LaunchApplication
doesn't seem to work. LaunchDeskAccessory doesn't work either. (I know but
I tried it anyway). Is OpenDeskAcc my only hope?

Has anybody done this? I can't post an event to the finder because it might
be closed or busy coping a file.

Thanks

Matt

+++++++++++++++++++++++++++

From: [e-mail] (Lawrence D'Oliveiro, Waikato University)
Date: 5 Sep 92 05:39:44 GMT
Organization: University of Waikato, Hamilton, New Zealand

In article <[e-mail]>, [e-mail] (Matthew Xavier Mora) writes:
> How do you launch a control panel under system 7? LaunchApplication
> doesn't seem to work. LaunchDeskAccessory doesn't work either. (I know but
> I tried it anyway). Is OpenDeskAcc my only hope?
>
> Has anybody done this? I can't post an event to the finder because it might
> be closed or busy coping a file.

Control panels don't run as separate processes with Finder 7. They run within
the Finder's process context. That's why there is no Process Manager call for
opening them; you really have to do it by posting an event to the Finder.

My Default Application control panel relies on this: that's how it's able to
patch the running Finder without installing INITs or any such black magic.

Lawrence D'Oliveiro                       fone: [phone]
Computer Services Dept                     fax: [phone]
University of Waikato            electric mail: [e-mail]
Hamilton, New Zealand    37^ 47' 26" S, 175^ 19' 7" E, GMT+12:00
The Internet protocol standardization process will now consist of three
stages: TRFCs (Tentative Requests for Comment), FRFCs (Firm Requests for
Comment), and DFCs (Demands for Comment).

---------------------------

From: [e-mail] (Brad Fowlow)
Subject: Top byte of 24-bit offscreen gworld?
Date: 3 Sep 92 18:51:40 GMT
Organization: Visual Edge Software, St. Laurent, Quebec

Can anyone say how quickly or terribly things might
go awry if I try to keep some extra info in the top 8 bits
of the pixel data of a 24-bit offscreen gworld?

That byte is awfully tempting as a place for alpha stuff.
And for the moment I'm not too concerned with how the code
will react under system 12; I just don't want sneaking
randomness to show up next week.
Have I missed something in IM6 that unequivocally rules
this out, or permits it?  Has anyone else been similiarly tempted?


- --
- -------------------------------------------------------------
 Brad Fowlow   [e-mail]     Visual Edge Software Limited

+++++++++++++++++++++++++++

From: [e-mail] (Lawrence D'Oliveiro, Waikato University)
Date: 4 Sep 92 17:47:49 +1200
Organization: University of Waikato, Hamilton, New Zealand

In article <[e-mail]>, [e-mail] (Brad Fowlow) writes:
> Can anyone say how quickly or terribly things might
> go awry if I try to keep some extra info in the top 8 bits
> of the pixel data of a 24-bit offscreen gworld?
>
> That byte is awfully tempting as a place for alpha stuff.
> And for the moment I'm not too concerned with how the code
> will react under system 12; I just don't want sneaking
> randomness to show up next week.
> Have I missed something in IM6 that unequivocally rules
> this out, or permits it?  Has anyone else been similiarly tempted?

I get the feeling from IM6 that there is no great crime in using the extra
byte for your own purposes. Just bear in mind that most QuickDraw drawing calls
clear that byte in pixels that they modify; I think it's only CopyBits and
its relatives that would preserve that byte, and then probably not in all
circumstances.

Basically Apple isn't interested in adding future alpha channel support or
making any future use of that byte. Or so I gather. Remember, at least one
of Apple's video cards doesn't even have RAM allocated to store that byte!

And, let's face it--what can you do with alpha channels, that you can't do
using "blend" mode with CopyBits, and blend mask pixmaps with
CopyMask/CopyDeepMask? These existing QuickDraw blending facilities are so much
more powerful...

Lawrence D'Oliveiro                       fone: [phone]
Computer Services Dept                     fax: [phone]
University of Waikato            electric mail: [e-mail]
Hamilton, New Zealand    37^ 47' 26" S, 175^ 19' 7" E, GMT+12:00
Q: Why do dogs make poor astronauts?
A: They keep sticking their head out the window and burning up on re-entry.

+++++++++++++++++++++++++++

From: Jim Cook <[e-mail]>
Organization: Prime Computer, Inc.
Date: Fri, 4 Sep 1992 18:10:47 GMT

In article <[e-mail]> [e-mail] (Brad Fowlow) writes:
>Can anyone say how quickly or terribly things might
>go awry if I try to keep some extra info in the top 8 bits
>of the pixel data of a 24-bit offscreen gworld?
>
>That byte is awfully tempting as a place for alpha stuff.
>And for the moment I'm not too concerned with how the code
>will react under system 12; I just don't want sneaking
>randomness to show up next week.
>Have I missed something in IM6 that unequivocally rules
>this out, or permits it?  Has anyone else been similiarly tempted?

The only think I know is that you better check the spec's on your video board.
Some video boards implement 32 bits per pixel and ignore the high 8 bits and
some board don't have the memory there to save money.  Check your board and
the boards of any other Macs you want to run on.

Since I don't know many video board vendors that make use of the fourth byte
in 32-bit (24-bit) color mode (TruVision was one vendor), I don't know how
rigorous Apple has been in testing to see that byte makes it out to the
video board complete and unchanged.  On the other hand, I don't have any
evidence that it won't - just idle curiosity.

Jim


+++++++++++++++++++++++++++

From: [e-mail] (Michael A. Kelly)
Organization: University of Oregon Computer and Information Sciences Dept.
Date: Fri, 4 Sep 1992 20:17:11 GMT

In article <[e-mail]> <[e-mail]> writes:
>In article <[e-mail]> [e-mail] (Brad Fowlow) writes:
>>Can anyone say how quickly or terribly things might
>>go awry if I try to keep some extra info in the top 8 bits
>>of the pixel data of a 24-bit offscreen gworld?
>>
>>That byte is awfully tempting as a place for alpha stuff.
>>And for the moment I'm not too concerned with how the code
>>will react under system 12; I just don't want sneaking
>>randomness to show up next week.
>>Have I missed something in IM6 that unequivocally rules
>>this out, or permits it?  Has anyone else been similiarly tempted?
>
>The only think I know is that you better check the spec's on your video board.
>Some video boards implement 32 bits per pixel and ignore the high 8 bits and
>some board don't have the memory there to save money.  Check your board and
>the boards of any other Macs you want to run on.

If the extra memory isn't available, the card should take care of that
itself.  Since there's no such thing as a 24-bit GWorld, those cards must
be taking the extra byte into account.

If a card does have the extra memory, and it uses that memory internally,
it should still be masking off the extra byte in a 32-bit GWorld.  If the
card has the memory but doesn't use it, it doesn't matter whether or not
it copies the extra byte.

This is all assuming you're using QuickDraw.

I haven't tested this, but it _should_ work that way.  Please correct me
if I'm wrong.

Mike.
- --
_____________________________________________________________________________
Michael A. Kelly                                         University of Oregon
[e-mail]                             Computer Science Department
_____________________________________________________________________________

+++++++++++++++++++++++++++

From: [e-mail] (Paul Campbell)
Date: 8 Sep 92 07:06:08 GMT
Organization: Taniwha Systems Design

In article <[e-mail]> [e-mail] (Brad Fowlow) writes:
>Can anyone say how quickly or terribly things might
>go awry if I try to keep some extra info in the top 8 bits
>of the pixel data of a 24-bit offscreen gworld?
>
>That byte is awfully tempting as a place for alpha stuff.
>And for the moment I'm not too concerned with how the code
>will react under system 12; I just don't want sneaking
>randomness to show up next week.
>Have I missed something in IM6 that unequivocally rules
>this out, or permits it?  Has anyone else been similiarly tempted?

Well you can go ahead and put data in the top byte BUT don't expect QuickDraw
to do anything usefull with it .... despite what IM sais a later note in
Develop said recently that you should NOT depend on CopyBits preserving
that byte - even if it dows now it might not in the future - or in all
the circumstances you can test today.

All 24-bit cards I know of that ship today do NOT preserve the top eight
bits a pixel - but then they aren't GWorlds and you can't get usefull data
on there with out CopyBits anyway

    Paul

- --
Paul Campbell    UUCP: ..!mtxinu!taniwha!paul     AppleLink: CAMPBELL.P

       "Most American's day to day experience of 'Family Values' is found in
    brightly colored fliers from such organisations as Target and K-Mart."

---------------------------

End of C.S.M.P. Digest
**********************