TweetFollow Us on Twitter

XCMD in Think C
Volume Number:5
Issue Number:5
Column Tag:HyperChat™

XCMD Corner: XCMDs in Think C

By Donald Koscheka, Arthur Young & Company, MacTutor Contributing Editor

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

Exploring XCMDs using just one development system is a lot like learning to play music on just one instrument. This is unfortunate because the Macintosh offers a virtual orchestra of development systems. As in learning to play a second instrument, learning a new development system often boils down to nothing more than learning how to transcribe the music.

Your programming environment is your instrument (writing a program is more like writing a piece of music than playing it). If you happen to own a copy of MPW you have no trouble using the code in this column because it’s all written for MPW. If you use a different development system , you’ll need to transcribe my listings to play on your particular development system.

In the past, I’ve been terribly guilty of catering to the MPW clique. My reasons were perhaps not so subtle: I use MPW at work; I’m comfortable with it, and I know that it directly supports an interface to XCMDs. After purchasing a copy of MPW 3.0, I realized that I might be making a mistake. For starters, MPW requires an expensive and time consuming learning curve; perhaps not everyone wants to spend several hundred dollars for sophistication they may never need.

Other development systems offer features that are not available in MPW such as a high quality source level debugger. Unfortunately several development systems lack key capabilities like support for XCMDs. Although you might expect LightspeedC to support XCMDs out of the box, it doesn’t. I’m not sure I understand the reason, but it doesn’t matter. Adding XCMD support to any compiler should be a very simple job.

Afterall, an XCMD is just another type of resource. If LightspeedC can create specialized resources such as window definitions and drivers, it already contains some of the support we need.

• Setting up the project

As luck, or design foresight, would have it, LightspeedC supports a generalized resource type called the “CODE” Resource. CODE resource projects are created like any other project in LightspeedC with the exception that you specify the project as a code resource in the set project type dialogue (see figure 1). You specify most of the information that the resource manger wants in this dialogue.

The custom header option requires a little elaboration. The standard interface to code resources branches to the entry point: main() . Selecting the Custom header option causes the entry point to be the first function in the file in which your main() is defined. XCMDs follow the second course as a matter of style.

Set the resource type to ‘XCMD’ or ‘XFCN’ according to the type of Hypercard interface you want.

Figure 1. Setting up a Code Resource using the Set Project Type Dialogue

• Writing the XCMD

In LightspeedC, a code resource has the same form as a “C” program. You define the entry point as:

 pascal void main( paramPtr ) 

ParamPtr is a pointer to a HyperTalk XCMDBlock. From there, your code looks like a vanilla “C” application. The same restrictions apply as on all CODE resources: no globals or statically initialized strings. CODE resources, of any kind, have no knowledge of globals at build time because they can’t make any assumptions about which application will load them! Strings suffer the same fate - “C” allocates statically defined strings in the application’s global pool. You’re not building an application so you don’t have a global pool - you must either define strings the hard way or load them in from the resource fork.

Listing 1 is a simple XCMD that returns the string “Hello World” to Hypercard. While the code itself is wholly unimaginative, it does demonstrate that the interface to Hypercard and the callback mechanism work satisfactorily. Anyhow there’s a time for imagination and a time to just get things done. Porting an interface falls to the latter category.

Include the header file, “HyperXCMD.h” (listing 2 ) in your code. This is the standard interface to Hypercard transposed for LightspeedC. There aren’t a lot of differences between the two as should be the case. Nonetheless this exercise proves quite useful in scoping out the idioms of a particular language implementation.

• The Hypercard “Glue”

You need to create a project which at the least includes MacTraps, your XCMD code and a special file called “XCMDGlue.c” (Listing 3) which interfaces (or glues) your XCMD to Hypertalk’s callback mechanism. I took the liberty of translating XCMDGlue.in.c from MPW “C” to LightspeedC. The major difference between the MPW and Think versions of the glue is that I use the CallPascal function available in LightspeedC to jump to the subroutine pointed to by paramPtr->entryPoint. Pascal routines push parameters from left to right and the subroutine is responsible for clearing the stack parameters. “C” pushes from right to left and the caller clears the stack.

We know that the callback engine uses the Pascal calling sequence because the parameters aren’t left on the stack after the call. Whether we push from right to left or left to right isn’t relevant here for an obvious reason that’s left as an exercise to the reader.

Add XCMDGlue.c to the project rather than including it at the end of the XCMDS source code as is the case with MPW. I like this feature of Think “C” - you keep track of the source modules at the project level and not at the source code level.

• Creating the resource

Once all modules compile,use the “Create Code Resource” menu option to create the code resource. LightspeedC presents a dialogue asking for the name of an output file. Enter the name of a file but not your output stack: LightspeedC completely erases the previous contents of both forks of the output file before writing out the code resource!

Select the “smart link” option when creating a code resource. Your links will be slower, but your XCMDs will be quite a bit smaller (The example in listing 3 compiles to 12.5K with smart link of and 2.5K with smart link on). Of course, you can speed up turnaround during development by leaving this option unselected.

That’s it! Use ResEdit or Rescopy to copy the XCMD into your stack. Perhaps LightspeedC will release a future version of “C” that will build code resources directly into the target file (if you try this now, the entire contents of the target file will be lost). In the meantime, the extra step needed to copy the resource into your stack is a small price to pay for an outstanding development system.

I hope the information in this article will help those of you who need to create an XCMD interface for another development system. The process is really rather simple and it provides you one of those rare opportunities in programming where you can get a lot done without doing a lot of work!

Listing 1:

/********************************/
/* File: SimpleXCMD.c*/
/* */
/* This is what a simple XCMD */
/* written in Lightspeed “C”*/
/* In order to build this code*/
/* resource, you will need the*/
/* two files “HyperXCMD.h” and*/
/* XCMDGlue.c.   */
/* */
/* ----------------------------  */
/* To Build:*/
/* */
/* (1) Create a project using */
/* this file as well as the */
/* XCMD.Glue.c file. (Set */
/* project type to XCMD (or */
/* XFCN) from the Project menu.  */
/* */
/* (2) Bring the project up to*/
/* date.*/
/* */
/* (3) Build Code Resource. */
/* */
/* (4) Use ResEdit to copy the   */
/* resource to your stack.*/
/********************************/

#include<MacTypes.h>
#include<OSUtil.h>
#include<MemoryMgr.h>
#include<FileMgr.h>
#include<ResourceMgr.h>
#include  “HyperXCmd.h”

pascal void main( paramPtr )
 XCmdBlockPtr  paramPtr;
{
 char theString[256];/* A “Pascal” String */

 theString[0] = ‘\0x0B’;  /* Remember, static*/
 theString[1] = ‘H’; /* strings are placed*/
 theString[2] = ‘E’; /* in the global pool*/
 theString[3] = ‘L’; /* CODE resources such */
 theString[4] = ‘L’; /* as XCMDS and XFCNS*/
 theString[5] = ‘O’; /* don’t have access to */
 theString[6] = ‘ ‘; /* globals so you have*/
 theString[7] = ‘W’; /* to discretely set the*/
 theString[8] = ‘O’; /* string’s value */
 theString[9] = ‘R’;
 theString[10]= ‘L’;
 theString[11]= ‘D’;

 /* A sample callback example */
 paramPtr->returnValue = PasToZero( paramPtr, &theString );
}
Listing 2:

/************************************/
/* File:HyperXCmd.h  */
/* */
/* Interface for standard */ 
/* HyperCard callback routines.    */
/* */
/* Based on original work by*/
/* Dan Winkler of Apple Computer */
/* */
/************************************/

typedef struct Str31 {
 char data[32];
 } Str31;
typedef  Str31 * Str31Ptr;

typedef struct XCmdBlock {
 short  paramCount;       
    Handle  params[16];
    Handle  returnValue;      
    Boolean passFlag; 
    
    void  (*entryPoint)();    
    short request;  
    short result;  
    longinArgs[8];
    longoutArgs[4];
} XCmdBlock;
typedef XCmdBlock*XCmdBlockPtr; 

  /* Callback codes  */
#define xresSucc 0
#define xresFail 1 
#define xresNotImp 2 
  
  /* Callback request codes */
#define xreqSendCardMessage 1 
#define xreqEvalExpr 2 
#define xreqStringLength  3 
#define xreqStringMatch   4 

#define xreqZeroBytes         6 
#define xreqPasToZero7 
#define xreqZeroToPas8 
#define xreqStrToLong9 
#define xreqStrToNum 10 
#define xreqStrToBool11 
#define xreqStrToExt 12 
#define xreqLongToStr13 
#define xreqNumToStr 14 
#define xreqNumToHex 15 
#define xreqBoolToStr16 
#define xreqExtToStr 17 
#define xreqGetGlobal18 
#define xreqSetGlobal19 
#define xreqGetFieldByName20 
#define xreqGetFieldByNum 21 
#define xreqGetFieldByID  22 
#define xreqSetFieldByName23 
#define xreqSetFieldByNum 24 
#define xreqSetFieldByID  25 
#define xreqStringEqual       26 
#define xreqReturnToPas       27 
#define xreqScanToReturn      28 
#define xreqScanToZero        39  

/* 
 “Prototypes” for the Callbacks.  Project 
 must include XCmdGlue.c.  
*/

 
pascal void SendCardMessage();     
pascal Handle  EvalExpr();
pascal long StringLength(); 
pascal Ptr  StringMatch();
pascal void ZeroBytes();
pascal Handle  PasToZero();
pascal void ZeroToPas();
pascal long StrToLong();
pascal long StrToNum();
pascal Boolean   StrToBool();
pascal void StrToExt();
pascal void LongToStr();
pascal void NumToStr();
pascal void NumToHex();
pascal void BoolToStr();
pascal void ExtToStr();
pascal Handle  GetGlobal();
pascal void SetGlobal();
pascal Handle  GetFieldByName();
pascal Handle  GetFieldByNum();
pascal Handle  GetFieldByID();
pascal void SetFieldByName();
pascal void SetFieldByNum();
pascal void SetFieldByID();
pascal Boolean   StringEqual();
pascal void ReturnToPas();
pascal void ScanToReturn();
pascal void ScanToZero();
Listing 3:

/************************************/
/* File: XCMDGlue.c*/
/* */
/* Callback routines for XCMDs*/
/* and XFCNs.  This file should  */
/* be included in your project*/
/* */
/* Based on original work by*/
/* Dan Winkler of Apple Computer */
/* */
/************************************/

#include<MacTypes.h>
#include<OSUtil.h>
#include<MemoryMgr.h>
#include<FileMgr.h>
#include<ResourceMgr.h>
#include  “HyperXCmd.h”
#include<math.h>

pascal void SendCardMessage(paramPtr,msg)
 XCmdBlockPtr  paramPtr;  
 StringPtrmsg;
/***********************
* Send a message back to 
* hypercard.  The input message
* is a Pascal String
***********************/
{
 paramPtr->inArgs[0] = (long)msg;
 paramPtr->request = xreqSendCardMessage;
    CallPascal( paramPtr->entryPoint );
}

pascal Handle EvalExpr(paramPtr,expr)
 XCmdBlockPtr  paramPtr;  
 StringPtrexpr;
/***********************
* Evaluate a Hypertalk expression
* returning the result as a “C” 
* string
***********************/
{
 paramPtr->inArgs[0] = (long)expr;
 paramPtr->request = xreqEvalExpr;
    CallPascal( paramPtr->entryPoint );
 return (Handle)paramPtr->outArgs[0];
}

pascal long StringLength(paramPtr,strPtr)
 XCmdBlockPtr  paramPtr;
 StringPtrstrPtr;
/***********************
* Counts the number of 
* characters in the input 
* string from StrPtr to end
* of string (zero byte)
***********************/
{
 paramPtr->inArgs[0] = (long)strPtr;
 paramPtr->request = xreqStringLength;
    CallPascal( paramPtr->entryPoint );
 return (long)paramPtr->outArgs[0];
}

pascal Ptr StringMatch(paramPtr,pattern,target)
 XCmdBlockPtr  paramPtr;  
 StringPtrpattern;
 Ptr    target;
/***********************
* Case-insensitive match 
* for pattern anywhere in
* target, 
* 
* Returns a pointer to first
* character of the first match,
* in target or NIL if no match
* found.  pattern is a Pascal string,
* and target is a zero-terminated string.
***********************/
{
 paramPtr->inArgs[0] = (long)pattern;
 paramPtr->inArgs[1] = (long)target;
 paramPtr->request = xreqStringMatch;
    CallPascal( paramPtr->entryPoint );
 return (Ptr)paramPtr->outArgs[0];
}

pascal void ZeroBytes(paramPtr,dstPtr,longCount)
 XCmdBlockPtr  paramPtr;  
 Ptr    dstPtr;  
 long   longCount;
/***********************
* Clear memory starting at destPtr
* through destPtr+longCount
***********************/
{
 paramPtr->inArgs[0] = (long)dstPtr;
 paramPtr->inArgs[1] = longCount;
 paramPtr->request = xreqZeroBytes;
    CallPascal( paramPtr->entryPoint );
}

pascal Handle PasToZero(paramPtr,pasStr)
 XCmdBlockPtr  paramPtr;
 StringPtrpasStr;
/***********************
* Convert a Pascal string (STR255)
* to a zero-terminated string.  
* Returns a handle to a zero-terminated
* string.  The caller must dispose the handle.
*
* Useful for setting the result or
* an argument you send from 
* an XCMD to HyperTalk.
***********************/
{
 paramPtr->inArgs[0] = (long)pasStr;
 paramPtr->request = xreqPasToZero;
    CallPascal( paramPtr->entryPoint );
 return (Handle)paramPtr->outArgs[0];
}

pascal void ZeroToPas(paramPtr,zeroStr,pasStr)
 XCmdBlockPtr  paramPtr;  
 char   *zeroStr;
 StringPtrpasStr;
/***********************
* Copy the zero-terminated
* string into the Pascal String.
*
* You create the Pascal string 
* and pass it by reference.
*
***********************/
{
 paramPtr->inArgs[0] = (long)zeroStr;
 paramPtr->inArgs[1] = (long)pasStr;
 paramPtr->request = xreqZeroToPas;
    CallPascal( paramPtr->entryPoint );
}

pascal long StrToLong(paramPtr,strPtr)
 XCmdBlockPtr  paramPtr;  
 Str31  *strPtr;
/***********************
* Convert a string of ASCII
* characters to an unsigned 
* long integer.
***********************/
{
 paramPtr->inArgs[0] = (long)strPtr;
 paramPtr->request = xreqStrToLong;
    CallPascal( paramPtr->entryPoint );
 return (long)paramPtr->outArgs[0];
}

pascal long StrToNum(paramPtr,str)
 XCmdBlockPtr  paramPtr;  
 Str31  *str;
/***********************
* Convert a string of ASCII
* characters to a signed 
* long integer.
***********************/
{
 paramPtr->inArgs[0] = (long)str;
 paramPtr->request = xreqStrToNum;
    CallPascal( paramPtr->entryPoint );
 return paramPtr->outArgs[0];
}

pascal Boolean StrToBool(paramPtr,str)
 XCmdBlockPtr  paramPtr;
 Str31  *str;
/***********************
* Convert the Pascal strings
* ‘true’ and ‘false’ to booleans.
***********************/
{
 paramPtr->inArgs[0] = (long)str;
 paramPtr->request = xreqStrToBool;
    CallPascal( paramPtr->entryPoint );
 return (Boolean)paramPtr->outArgs[0];
}

pascal void StrToExt(paramPtr,str,myext)
 XCmdBlockPtr  paramPtr;
 Str31  *str;  
 long   *myext;
/***********************
* Convert a string of ASCII digits 
* to an extended long integer.
*
* The return value is passed
* by reference and you must
* asllocate the space before 
* calling this routine.
***********************/
{
 paramPtr->inArgs[0] = (long)str;
 paramPtr->inArgs[1] = (long)myext;
 paramPtr->request = xreqStrToExt;
    CallPascal( paramPtr->entryPoint );
}

pascal void LongToStr(paramPtr,posNum,mystr)
 XCmdBlockPtr  paramPtr;  
 long   posNum;  
 Str31  *mystr;
/***********************
* Convert an unsigned long integer
* to a pascal string representation
* Useful for sending numbers back 
* to Hypercard.
*
*  You create mystr and pass
* it by reference.
***********************/
{
 paramPtr->inArgs[0] = (long)posNum;
 paramPtr->inArgs[1] = (long)mystr;
 paramPtr->request = xreqLongToStr;
    CallPascal( paramPtr->entryPoint );
}

pascal void NumToStr(paramPtr,num,mystr)
 XCmdBlockPtr  paramPtr;  
 long   num;
 Str31  *mystr;
/***********************
* Convert a signed long integer
* to a pascal string representation
* Useful for sending numbers back 
* to Hypercard.
*
*  You create mystr and pass
* it by reference.
***********************/
{
 paramPtr->inArgs[0] = num;
 paramPtr->inArgs[1] = (long)mystr;
 paramPtr->request = xreqNumToStr;
    CallPascal( paramPtr->entryPoint );
}

pascal void NumToHex(paramPtr,num,nDigits,mystr)
 XCmdBlockPtr  paramPtr;  
 long   num;
 short  nDigits; 
 Str31  *mystr;
/***********************
* Convert an unsigned long integer
* to a hexadecimal number and put it
* into a Pascal string.
*
* The “output” string is passed
* by reference.
***********************/
{
 paramPtr->inArgs[0] = num;
 paramPtr->inArgs[1] = nDigits;
 paramPtr->inArgs[2] = (long)mystr;
 paramPtr->request = xreqNumToHex;
    CallPascal( paramPtr->entryPoint );
}

pascal void BoolToStr(paramPtr,bool,mystr)
 XCmdBlockPtr  paramPtr;  
 Booleanbool;  
 Str31  *mystr;
/***********************
* Convert a boolean to 
* ‘true’ or ‘false’.  
*
* The “output” string is passed
* by reference.
***********************/
{
 paramPtr->inArgs[0] = (long)bool;
 paramPtr->inArgs[1] = (long)mystr;
 paramPtr->request = xreqBoolToStr;
    CallPascal( paramPtr->entryPoint );
}

pascal void ExtToStr( paramPtr, myext, mystr)
 XCmdBlockPtr  paramPtr;  
 char   *myext;  
 Str31  *mystr;
/***********************
* Convert an extended long
* to its string representation
*
* The “output” string is passed
* by reference.
***********************/
{
 paramPtr->inArgs[0] = (long)myext;
 paramPtr->inArgs[1] = (long)mystr;
 paramPtr->request = xreqExtToStr;
    CallPascal( paramPtr->entryPoint );
}

pascal Handle GetGlobal(paramPtr,globName)
 XCmdBlockPtr  paramPtr;  
 StringPtrglobName;
/***********************
* Return a handle to a zero-terminated
* string containing the value of 
* the specified HyperTalk global variable.
***********************/
{
 paramPtr->inArgs[0] = (long)globName;
 paramPtr->request = xreqGetGlobal;
    CallPascal( paramPtr->entryPoint );
 return (Handle)paramPtr->outArgs[0];
}

pascal void SetGlobal(paramPtr,globName,globValue)
 XCmdBlockPtr  paramPtr;  
 StringPtrglobName;
 Handle globValue;
/***********************
* Set the value of the specified 
* HyperTalk global variable to be
* the zero-terminated string in globValue.
* The contents of globValue
* are copied, you dispose the
* handle
***********************/
{
 paramPtr->inArgs[0] = (long)globName;
 paramPtr->inArgs[1] = (long)globValue;
 paramPtr->request = xreqSetGlobal;
    CallPascal( paramPtr->entryPoint );
}

pascal Handle GetFieldByName(paramPtr,cardFieldFlag,fieldName)
 XCmdBlockPtr  paramPtr;  
 BooleancardFieldFlag;
 StringPtrfieldName;
/***********************
* Return a handle to a zero-terminated
* string containing the value of 
* field fieldName on the current 
* card.  You must dispose the handle.
*
* Set cardfieldFlag to ture if
* you want the contents of a card
* field or to false if you want
* the contents of a bkgnd field
***********************/
{
 paramPtr->inArgs[0] = (long)cardFieldFlag;
 paramPtr->inArgs[1] = (long)fieldName;
 paramPtr->request = xreqGetFieldByName;
    CallPascal( paramPtr->entryPoint );
 return (Handle)paramPtr->outArgs[0];
}

pascal Handle GetFieldByNum(paramPtr,cardFieldFlag,fieldNum)
 XCmdBlockPtr  paramPtr;  
 BooleancardFieldFlag;
 short  fieldNum;
/***********************
* Returns a copy of the contents of the field whose number is
* fieldnum on the current card.
* You dispose the handle when you are done.
***********************/
{
 paramPtr->inArgs[0] = (long)cardFieldFlag;
 paramPtr->inArgs[1] = fieldNum;
 paramPtr->request = xreqGetFieldByNum;
    CallPascal( paramPtr->entryPoint );
 return (Handle)paramPtr->outArgs[0];
}

pascal Handle GetFieldByID(paramPtr,cardFieldFlag,fieldID)
 XCmdBlockPtr  paramPtr;  
 BooleancardFieldFlag;
 short  fieldID;
/***********************
* Returns a copy of the contents of the field whose id is
* fieldID on the current card.
* You dispose the handle when you are done.
***********************/
{
 paramPtr->inArgs[0] = (long)cardFieldFlag;
 paramPtr->inArgs[1] = fieldID;
 paramPtr->request = xreqGetFieldByID;
    CallPascal( paramPtr->entryPoint );
 return (Handle)paramPtr->outArgs[0];
}

pascal void SetFieldByName(paramPtr,cardFieldFlag,fieldName,fieldVal)
 XCmdBlockPtr  paramPtr;  
 BooleancardFieldFlag;
 StringPtrfieldName; 
 Handle fieldVal;
/***********************
* Set the value of the field whose name is fieldName on 
* the current card.
* You dispose the handle when you are done.
***********************/
{
 paramPtr->inArgs[0] = (long)cardFieldFlag;
 paramPtr->inArgs[1] = (long)fieldName;
 paramPtr->inArgs[2] = (long)fieldVal;
 paramPtr->request = xreqSetFieldByName;
    CallPascal( paramPtr->entryPoint );
}

pascal void SetFieldByNum(paramPtr,cardFieldFlag,fieldNum,fieldVal)
 XCmdBlockPtr  paramPtr;  
 BooleancardFieldFlag;
 short  fieldNum;
 Handle fieldVal;
/***********************
* Set the value of the field whose number is fieldnum on 
* the current card.
* You dispose the handle when you are done.
***********************/
{
 paramPtr->inArgs[0] = (long)cardFieldFlag;
 paramPtr->inArgs[1] = fieldNum;
 paramPtr->inArgs[2] = (long)fieldVal;
 paramPtr->request = xreqSetFieldByNum;
    CallPascal( paramPtr->entryPoint );
}

pascal void SetFieldByID(paramPtr,cardFieldFlag,fieldID,fieldVal)
 XCmdBlockPtr  paramPtr;  
 BooleancardFieldFlag;
 short  fieldID; 
 Handle fieldVal;
/***********************
* Set the value of the field whose id is fieldID on 
* the current card.
* You dispose the handle when
* you are done.
***********************/
{
 paramPtr->inArgs[0] = (long)cardFieldFlag;
 paramPtr->inArgs[1] = fieldID;
 paramPtr->inArgs[2] = (long)fieldVal;
 paramPtr->request = xreqSetFieldByID;
    CallPascal( paramPtr->entryPoint );
}

pascal Boolean StringEqual(paramPtr,str1,str2)
 XCmdBlockPtr  paramPtr;  
 Str31  *str1; 
 Str31  *str2;
/***********************
* Returns true if the strings match, false otherwise.
* Compare is case insensitive
***********************/
{
 paramPtr->inArgs[0] = (long)str1;
 paramPtr->inArgs[1] = (long)str2;
 paramPtr->request = xreqStringEqual;
    CallPascal( paramPtr->entryPoint );
 return (Boolean)paramPtr->outArgs[0];
}

pascal void ReturnToPas(paramPtr,zeroStr,pasStr)
 XCmdBlockPtr  paramPtr;  
 Ptr    zeroStr; 
 StringPtrpasStr;
/***********************
* Collect characters from zeroStr
* to the next carriage Return and return 
* them in the Pascal string pasStr. 
* If no Return found, collect chars
* until the end of the string (zero)
***********************/
{
 paramPtr->inArgs[0] = (long)zeroStr;
 paramPtr->inArgs[1] = (long)pasStr;
 paramPtr->request = xreqReturnToPas;
    CallPascal( paramPtr->entryPoint );
}

pascal void ScanToReturn(paramPtr,scanHndl)
 XCmdBlockPtr  paramPtr;  
 Ptr    *scanHndl;
/***********************
* Position the pointer, scanPtr,at a Return character
* or a zero byte. 
***********************/
{
 paramPtr->inArgs[0] = (long)scanHndl;
 paramPtr->request = xreqScanToReturn;
    CallPascal( paramPtr->entryPoint );
}

pascal void ScanToZero(paramPtr,scanHndl)
 XCmdBlockPtr  paramPtr;  
 Ptr    *scanHndl;
/***********************
* Position the pointer, scanPtr,
* at a  zero byte. 
***********************/
{
 paramPtr->inArgs[0] = (long)scanHndl;
 paramPtr->request = xreqScanToZero;
    CallPascal( paramPtr->entryPoint );
}

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Latest Forum Discussions

See All

Can PokeMatch help you find love with Po...
The unofficial Pokemon GO companion app space has exploded almost as fast as the game itself over the last few weeks. Aspiring app developers, many of them working solo, have given us apps that locate Pokemon, keep track of the server status, and... | Read more »
How to get started with Prisma
If there's one thing people like to do more than taking pictures with their smartphones, it's tinkering with those photos in some way. Numerous apps have sprung up over the last several years that allow you to use filters and special effects to... | Read more »
6 Pokemon GO updates you can expect, acc...
Pokemon GO had a scheduled appearance at this year's San Diego Comic-Con for a while, but it was only relatively close to the show that it was upgraded to a spot in Hall H. That's the biggest venue at SDCC, one usually reserved for the largest... | Read more »
How to evolve Eevee in Pokemon GO
By now, almost everyone should be hip to how to evolve Pokemon in Pokemon GO (and if not, there's a guide for that). Just gather enough candy of the appropriate type, feed them all to the Pokemon, and evolution happens. It's a miracle that would... | Read more »
CSR Racing 2: Guide to all game modes
It might not seem like there are all that many ways to go fast in a straight line, but CSR Racing 2 begs to differ. [Read more] | Read more »
Bulb Boy (Games)
Bulb Boy 1.0 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0 (iTunes) Description: Multi-award winning 2D point & click horror adventure about a boy with a glowing head. | Read more »
5 top free emoji keyboard apps
If we're not at peak emoji yet as a society, it feels like we definitely should be. The emoji concept has gone far beyond what anyone in Japan could have envisioned when the people there unleashed it on an unsuspecting world, but the West has... | Read more »
How to unlock more characters in Disney...
One of the big charms of Disney Emoji Blitz is seeing a wide variety of beloved Disney and Pixar characters transformed into smiling emojis. Even someone like the sneaky Randall from Monsters Inc., who probably never cracked a smile on film, is... | Read more »
Cubway (Games)
Cubway 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Cubway is a journey with an abstract story of lifecycle of rebirth, called Samsara. Guide the cube through the long way full of dangers... | Read more »
Colorcube (Games)
Colorcube 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: Turn pieces and blend colours in this minimal yet visually stunning puzzler.Over 200 handcrafted and challenging levels. Features... | Read more »

Price Scanner via MacPrices.net

Clearance 12-inch Retina MacBooks, Apple refu...
Apple has Certified Refurbished 2015 12″ Retina MacBooks available starting at $929. Apple will include a standard one-year warranty with each MacBook, and shipping is free. The following... Read more
13-inch Retina MacBook Pros on sale for up to...
B&H Photo has 13″ Retina MacBook Pros on sale for up to $150 off MSRP. Shipping is free, and B&H charges NY tax only: - 13″ 2.7GHz/128GB Retina MacBook Pro: $1199 $100 off MSRP - 13″ 2.7GHz/... Read more
13-inch 1.6GHz/128GB MacBook Air on sale for...
Amazon has the 13″ 1.6GHz/128GB MacBook Air on sale for $200 off MSRP for a limited time. Shipping is free: - 13″ 1.6GHz/128GB MacBook Air (sku MMGF2LL/A): $799.99 $200 off MSRP Their price is the... Read more
13-inch 1.6GHz/256GB MacBook Air on sale for...
Amazon has the 13″ 1.6GHz/256GB MacBook Air on sale for $200 off MSRP for a limited time. Shipping is free: - 13″ 1.6GHz/256GB MacBook Air (sku MMGG2LL/A): $999.99 $200 off MSRP Their price is the... Read more
Free iOS Business App notably* Helps Service...
PayStudio Inc. has introduced their new business app notably* 1.0, developed for iPhone and iPod touch. notably* was specifically developed to help service and trade professionals go digital and... Read more
27-inch iMacs on sale for $200 off MSRP
Amazon has 27″ iMacs on sale for $200 off MSRP including free shipping: - 27″ 3.3GHz iMac 5K: $2099 $200 off MSRP - 27″ 3.2GHz/1TB Fusion iMac 5K: $1799.99 $200 off MSRP - 27″ 3.2GHz/1TB HD iMac 5K... Read more
Mac Pros on sale for $200 off MSRP
B&H Photo has Mac Pros on sale for $200 off MSRP. Shipping is free, and B&H charges sales tax in NY only: - 3.7GHz 4-core Mac Pro: $2799, $200 off MSRP - 3.5GHz 6-core Mac Pro: $3799, $200... Read more
Save up to $600 with Apple refurbished Mac Pr...
Apple has Certified Refurbished Mac Pros available for up to $600 off the cost of new models. An Apple one-year warranty is included with each Mac Pro, and shipping is free. The following... Read more
Apple price trackers, updated continuously
Scan our Apple Price Trackers for the latest information on sales, bundles, and availability on systems from Apple’s authorized internet/catalog resellers. We update the trackers continuously: - 15″... Read more
13-inch 2.5GHz MacBook Pro (Apple refurbished...
Apple has Certified Refurbished 13″ 2.5GHz MacBook Pros available for $829, or $270 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free: - 13″ 2.5GHz MacBook Pros... Read more

Jobs Board

*Apple* Retail - Multiple Positions, Willow...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
*Apple* Evangelist - JAMF Software (United S...
The Apple Evangelist is responsible for building and cultivating strategic relationships with Apple 's small and mid-market business development field teams. This Read more
*Apple* Solutions Consultant - APPLE (United...
Job Summary As an Apple Solutions Consultant, you'll be the link between our future customers and our products. You'll showcase your entrepreneurial spirit as you Read more
*Apple* Professional Learning Specialist - A...
Job Summary The Apple Professional Learning Specialist is a full-time position for one year with Apple in the Phoenix, AZ area. This position requires a high Read more
*Apple* Picker - Apple Hill Orchard (United...
Apple Hill Orchard, Co. Rte. 21,Whitehall, NY 9/7/16-10/228/16. Pick fresh market or processing apples Productivity of 60 boxes and 80 boxes processing fruit per Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.