TweetFollow Us on Twitter

ADB Count
Volume Number:6
Issue Number:5
Column Tag:XCMD Corner

Related Info: ADB Manager

CountADBs and Reality

By Donald Koscheka, , Mark Armstrong

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

This column strives to present interesting insights into enhancing Hypercard through XCMDs. When I started writing this column almost two years ago, I was apprehensive; how would I come up with a new idea each month year in and year out. The answer to this question was something of a revelation to me -- once I decided to keep coming up with new ideas, I began looking in new places for those ideas. No part of Macintosh programming is off-limits, I explore everything. Of course there are limits to what one person can do and I find myself very often writing a column in response to some question asked by a colleague or a reader.

I’ve decided that it’s time to go one step further. Beginning this month, intermittently offer this space for “guest XCMDs” such as Mark Armstrong’s following ADB externals. The guest columnist idea appeals to me for two reasons: (1) it broadens the column’s “reach” by discussing areas that I may have not explored myself and (2) it provides you with different perspectives and coding styles so that you can see how others have solved specific problems in an XCMD. This is an open invitation. If you would like to have your XCMD published, send it to me via AppleLink (N0735) or America OnLine (AFC Donald) or to the Editor. Use Macwrite or TEXT only. I will respond as quickly as possible to inform you as to whether I can use the article or not. A few rules: If I can use the material, I will edit it and return it to you for approval. I edit for style and grammar, expect to have some work done to your prose. Don’t submit anything that you don’t want in the public domain and don’t submit any article without source code. You may use whatever language you like. Give yourself a “short plug” at the beginning of the column so that other readers get to know you better.

This month, I would like to introduce Mark Armstrong, Vice President of Research and Development at Pharos Technologies, Inc, a software development and systems integration company in Cincinnati, Ohio. Mark has written one commercial engineering application on the Macintosh called “UNITize” and has contributed to the arcade-style game “Marble Madness”. With his physics degree firmly in hand, he still wonders how he got mixed up in all this.

CountADBs and Reality

In some circumstances (such as on the factory floor), there is a need to monitor the Macintosh to determine whether the mouse or keyboard devices become detached from ADB. Some software may modify their behavior if certain input devices are available, hiding or showing functionality based on that result. Below are two simple XFCN’s, developed in Think C 4.0, that tell you if the mouse and keyboard are connected.

According to Inside Macintosh Volume 5, the function CountADBs() “returns a value representing the number of devices connected to the Apple Desktop Bus (ADB) by counting the number of entries in the device table....” The important word is representing. It does not really tell you what is connected out there on the bus. Consequently, even if you have no devices hooked up to ADB, CountADBs() will return a value of 2. This happens because the system always installs the keyboard and mouse drivers regardless of whether they are physically resident. To find out what is really connected to ADB you can poll devices that you believe are connected to the ADB. Connected devices will respond to the poll.

Before going too far, you must determine whether the host machine is equipped for ADB. The following call to SysEnvirons() determines whether ADB is installed.

/* 1 */

Boolean ADBExists()
 {
 SysEnvRectheWorld;
 OSErr  err;
 
 err = SysEnvirons(1,&theWorld);
 if (err) return (FALSE);
 else
 {
if ((theWorld.machineType >= 0) && (theWorld.machineType < 3)) 
 return (FALSE);
 else return (TRUE);
 }
 }

Once you have determined that ADB exists on your machine, you check to see what devices are actually there by looping from 1 to the maximum allowable number of ADB devices (16). Inside the loop, you call ADBIndAvail() which returns TRUE if the specified device is physically connected and functional or FALSE otherwise. ADBIndAvail() takes a device specified by the index and sends a command via ADBOp() to that device to see if it is responding. If the device receives the operation, it will signal that it has done so by executing a completion routine. If the completion routine ADBOp() doesn’t execute, then the device did not receive the message, and we can assume that the device is dysfunctional or disconnected. The completion routine ADBComplete() sets a global variable to TRUE. If completion does not occur, then the operation times out and the global variable remains FALSE. In the following code, we use the first byte of Scratch8 as the global variable. We chose to use Scratch8 because this code was developed for a Think C 4.0 XCMD where A4 had already been pushed using SetUpA4(). In most cases, a regular global variable will do the trick.

/* 2 */

#define ADB_TIMEOUT10000

extern char Scratch8[]  : 0x9FA;

ADBComplete(){
 *(char *)Scratch8 = TRUE;
}

ADBIndAvail(index)
 short  index;
 {
 ADBAddress addrs;
 ADBDataBlock  devBlock;
 OSErr  err;
 short  cmdNum;
 Str255 ADBData;
 
 addrs = GetIndADB(&devBlock,index);
 cmdNum = ((addrs*16)+0xF);
 ADBData[0] = 0;
 ADBData[1] = 0;
 ADBData[2] = 0;
 
 *(char *)Scratch8 = FALSE;
 err = ADBOp(NIL,ADBComplete,&ADBData,cmdNum);
 if (!err){
 short I= 0;
 do
 if (++I > ADB_TIMEOUT) *(char *)Scratch8 = TRUE; 
 while (!*(char *)Scratch8);
 if (ADBData[0] != 0) return (TRUE);
 }
 return (FALSE);
}

In both cases below, the first portion of the code checks to see if the first and only argument is a question mark (?) or an exclamation point (!). If so, the XFCN responds appropriately as suggested by MacDTS.

The XFCN checks first to see if ADB exists on this machine and returns an error code if it does not. Next, it loops through all the devices to see if any one of them is a responding mouse. If it finds one, it returns TRUE, otherwise it completes the loop and returns FALSE. Each time through the loop, we call GetIndADB(), as directed in Inside Mac, to determine if the device in question is, indeed, a mouse.

/* 3 */

#include “MacTypes.h”
#include “HyperXCmd.h”
#include “DeskBus.h”
#include “SetUpA4.h”

#define ADB_KEYBOARD 2
#define ADB_MOUSE3

#define STANDARD_KBD 1
#define EXTENDED_KBD 2

#define MAX_ADB_DEVICES 16

pascal main(paramPtr)
   XCmdBlockPtr  paramPtr;
   {
   Str255 str;
   shortix;
   
   RememberA0();
   SetUpA4();
   
   if(paramPtr->paramCount == 1){
   ZeroToPas(paramPtr,*((unsigned char **)paramPtr->params[0]),str);
      if (str[0] == 1){
        if (str[1] == ‘?’) 
 pstrcpy(str,”\pKBDAvail()”);
        else if (str[1] == ‘!’) 
 pstrcpy(str,”\pv1.0; © Pharos Technologies, Inc. 1989");
      }
      goto Done;
   }
   
   if (!ADBExists()){ 
 pstrcpy(str,”\p0\rnoADB”); 
 goto Done; 
 }
   
 for ( ix  =1; ix <=MAX_ADB_DEVICES; ix ++){
 ADBDataBlock    ADBinfo;
 ADBAddress ADBaddr;
 
 if (!ADBIndAvail( ix )) continue;
 ADBaddr = GetIndADB(&ADBinfo,I);
 if (ADBaddr <= 0) continue;
 if (ADBinfo.origADBAddr == ADB_MOUSE){ 
 pstrcpy(str,”\ptrue”); 
 goto Done; 
 }
 }
 pstrcpy(str,”\pfalse”);
Done:
   paramPtr->returnValue = PasToZero(paramPtr,(StringPtr)str);
   RestoreA4();
}

A similar routine checks for keyboard devices. This routine not only checks to see if it is a keyboard, but also returns the type of keyboard by examining the devType field of ADBInfo.

/* 4 */

#include “MacTypes.h”
#include “HyperXCmd.h”
#include “DeskBus.h”
#include “SetUpA4.h”

#define ADB_KEYBOARD 2
#define ADB_MOUSE3
#define STANDARD_KBD 1
#define EXTENDED_KBD 2
#define MAX_ADB_DEVICES 16

pascal main(paramPtr)
   XCmdBlockPtr  paramPtr;
   {
   Str255 str;
   shortI;
   
   RememberA0();
   SetUpA4();
   
   if (paramPtr->paramCount == 1){
   ZeroToPas(paramPtr,*((unsigned char **)paramPtr->params[0]),str);
      if (str[0] == 1){
        if (str[1] == ‘?’) 
 pstrcpy(str,”\pKBDAvail()”);
        else if (str[1] == ‘!’) 
 pstrcpy(str,”\pv1.0; © Pharos Technologies, Inc. 1989");
      }
      goto Done;
    }
   
   if (!ADBExists()){ 
 pstrcpy(str,”\p0\rnoADB”); 
 goto Done; 
 }
   
 for (I=1;I<=MAX_ADB_DEVICES;I++){
 ADBDataBlock    ADBinfo;
 ADBAddress ADBaddr;
 
 if (!ADBIndAvail(I)) continue;
 ADBaddr = GetIndADB(&ADBinfo,I);
 if (ADBaddr <= 0) continue;

 if (ADBinfo.origADBAddr == ADB_KEYBOARD){
 if (ADBinfo.devType == STANDARD_KBD){ 
 pstrcpy(str,”\ptrue,standard”); 
 goto Done; 
 }
 else if (ADBinfo.devType == EXTENDED_KBD){ 
 pstrcpy(str,”\ptrue,extended”); 
 goto Done; 
 }
 else{ 
 pstrcpy(str,”\ptrue,unknown”); 
 goto Done; 
 }
 }
 }
 pstrcpy(str,”\pfalse”);
Done:
   paramPtr->returnValue = PasToZero(paramPtr,(StringPtr)str);
   RestoreA4();
   }

Once you know how to identify a particular device, it is easy to check to see if it is present on ADB. If you don’t know how to identify a given device, then the code above can be easily modified to return all devices found on ADB. By the way, I would like to give special thanks and credit to Cameron Birse. If you don’t recognize the name from any number of “sources”, then never mind.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

BBEdit 11.0.3 - Powerful text and HTML e...
BBEdit is the leading professional HTML and text editor for the Mac. Specifically crafted in response to the needs of Web authors and software developers, this award-winning product provides a... Read more
Microsoft Office Preview 15.8 - Popular...
Welcome to the new and modern Microsoft Office for Mac. You will receive regular updates automatically until the official release in the second half of 2015. With the redesigned Ribbon and your... Read more
Yosemite Cache Cleaner 9.0.5 - Clear cac...
Yosemite Cache Cleaner is an award-winning general purpose tool for OS X. YCC makes system maintenance simple with an easy point-and-click interface to many OS X functions. Novice and expert users... Read more
ExpanDrive 4.3.2 - Access cloud storage...
ExpanDrive builds cloud storage in every application, acts just like a USB drive plugged into your Mac. With ExpanDrive, you can securely access any remote file server directly from the Finder or... Read more
RapidWeaver 6.0.8 - Create template-base...
RapidWeaver is a next-generation Web design application to help you easily create professional-looking Web sites in minutes. No knowledge of complex code is required, RapidWeaver will take care of... Read more
Artlantis Studio 5.1.2.7 - 3D rendering...
Artlantis Studio is a unique and ideal tool for performing very high resolution rendering easily and in real time. The new FastRadiosity engine now lets you compute images in radiosity-even in... Read more
MacUpdate Desktop 6.0.5 - Search and ins...
MacUpdate Desktop 6 brings seamless 1-click installs and version updates to your Mac. With a free MacUpdate account and MacUpdate Desktop 6, Mac users can now install almost any Mac app on macupdate.... Read more
BitTorrent Sync 2.0.82 - Sync files secu...
BitTorrent Sync allows you to sync unlimited files between your own devices, or share a folder with friends and family to automatically sync anything. File transfers are encrypted. Your information... Read more
Google Drive 1.20 - File backup and shar...
Google Drive is a place where you can create, share, collaborate, and keep all of your stuff. Whether you're working with a friend on a joint research project, planning a wedding with your fiancé, or... Read more
Simon 4.0.3 - Monitor changes and crashe...
Simon monitors websites and alerts you of crashes and changes. Select pages to monitor, choose your alert options, and customize your settings. Simon does the rest. Keep a watchful eye on your... Read more

Bored? MyLeisure FreeTime Maximizer Will...
Bored? MyLeisure FreeTime Maximizer Will Take Care of That! Posted by Jessica Fisher on March 5th, 2015 [ permalink ] iPhone App - Designed for the iPhone, compatible with the iPad | Read more »
New Publisher Allstar Games Heads West w...
Allstar Games has announced its first mobile title designed for western audiences, Allstar Heroes. The game will be a massive online battle arena (MOBA) that offers dozens of heroes for you to collect and pit against your opponents. As each hero has... | Read more »
RAD Boarding Review
RAD Boarding Review By Jennifer Allen on March 5th, 2015 Our Rating: :: NEARLY RADUniversal App - Designed for iPhone and iPad RAD Boarding isn’t quite one of the greats, but it has potential.   | Read more »
Presenting the International Mobile Gami...
11th Annual International Mobile Gaming Awards ceremony, hosted by actress Allison Haislip, gathered mobile game developers and publishers from around the world. They chose 13 winners out of the 93 nominations. British studio USTWO won the the Grand... | Read more »
AG Drive Review
AG Drive Review By Tre Lawrence on March 5th, 2015 Our Rating: :: FUTURISTIC STREET RACING.Universal App - Designed for iPhone and iPad Futuristic racing… interstellar style.   | Read more »
GDC 2015 – Nightmare Guardians is an Int...
GDC 2015 – Nightmare Guardians is an Interesting Hybrid of MOBA and Lane Defense Posted by Rob Rich on March 5th, 2015 [ permalink ] I have to say that lane defense (i.e. | Read more »
Overkill 3 Review
Overkill 3 Review By Tre Lawrence on March 5th, 2015 Our Rating: :: WHO'S NEXT?Universal App - Designed for iPhone and iPad Cover system gameplay in the third-person.   Developer: Craneballs Price: Free Version Reviewed: 1.1.6... | Read more »
Warner Bros. Interactive Entertainment A...
Warner Bros. has some exciting games coming down the pipe! | Read more »
GDC 2015 – Star Trek Timelines will Prob...
GDC 2015 – Star Trek Timelines will Probably Make Your Inner Trekkie Squeal With Glee Posted by Rob Rich on March 4th, 2015 [ permalink ] Any popular fictional universe has its fair share of fan fiction – where belo | Read more »
Protect Yourself from an Onslaught of Ca...
Surprise Attack Games has announced a Cat-astrophic new physics puzzler called Fort Meow! In the game, a young girl named Nia finds her grandfather’s journal which triggers an all mighty feline attack! Why do the cats want the journal? Who knows,... | Read more »

Price Scanner via MacPrices.net

Apple restocks refurbished 15-inch Retina Mac...
The Apple Store has restocked Apple Certified Refurbished 2014 15″ Retina MacBook Pros, available for up to $400 off the cost of new models. An Apple one-year warranty is included with each model,... Read more
Roundup of MacBook Air sale prices, models up...
B&H Photo has MacBook Airs on sale for up to $100 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 11″ 128GB MacBook Air: $799 100 off MSRP - 11″ 256GB MacBook Air: $999 $100... Read more
New Firstrade Mobile App Enables On-The-Go Tr...
Firstrade Securities Inc. has announced its new mobile app, which gives investors immediate access to the company’s trading platform on all mobile devices. The app was developed in-house and was... Read more
Sonnet Introduces USB 3.0 + eSATA Thunderbolt...
Sonnet has announced the launch of its new USB 3.0 + eSATA Thunderbolt Adapter for easy connectivity to USB 3.0 devices and eSATA storage, and USB 3.0 + Gigabit Ethernet Thunderbolt Adapter for easy... Read more
Apple restocks refurbished 27-inch 5K iMacs f...
The Apple Store has restocked Apple Certified Refurbished 27″ 3.5GHz 5K iMacs for $2119 including free shipping. Their price is $380 off the cost of new models, and it’s the lowest price available... Read more
Free Clean Reader Mobile App Hides Swear Word...
The new Clean Reader app, now available in the Apple App Store and Google Play, delivers the opportunity of reading any book without being exposed to profanity. By selecting how clean they want their... Read more
Kinsa Launches “Groups” App to Monitor Illnes...
Kinsa, makers of the first FDA approved app-enabled smartphone thermometer thst won the 2013 Cleveland Clinic Medical Innovation Grand Prize and recently appeared in Apple’s “Parenthood” TV... Read more
iPad: A More Positive Outlook – The ‘Book Mys...
It’s good to hear someone saying positive things about the iPad. I’ve been trying to bend my mind around how Apple’s tablet could have gone from zero to bestselling personal computing device on the... Read more
Mac Pros on sale for up to $279 off MSRP
Amazon has Mac Pros in stock and on sale for up to $279 off MSRP. Shipping is free: - 4-Core Mac Pro: $2725.87, $273 off MSRP (9%) - 6-Core Mac Pro: $3719.99, $279 off MSRP (7%) Read more
Sale! 13-inch Retina MacBook Pros for up to $...
B&H Photo has 13″ Retina MacBook Pros on sale for up to $205 off MSRP. Shipping is free, and B&H charges NY sales tax only: - 13″ 2.6GHz/128GB Retina MacBook Pro: $1219.99 save $80 - 13″ 2.... Read more

Jobs Board

*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
*Apple* Solutions Consultant - Retail Sales...
**Job Summary** As an Apple Solutions Consultant (ASC) you are the link between our customers and our products. Your role is to drive the Apple business in a retail Read more
Position Opening at *Apple* - Apple (United...
…Summary** As a Specialist, you help create the energy and excitement around Apple products, providing the right solutions and getting products into customers' hands. You Read more
Position Opening at *Apple* - Apple (United...
**Job Summary** The Apple Store is a retail environment like no other - uniquely focused on delivering amazing customer experiences. As an Expert, you introduce people Read more
*Apple* Solutions Consultant - Retail Sales...
**Job Summary** As an Apple Solutions Consultant (ASC) you are the link between our customers and our products. Your role is to drive the Apple business in a retail Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.