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

How to maximise your profits in Bakery B...
Running a bakery can be an expensive venture. You’ll need to continuously upgrade your oven, your kitchen supplies, and even your ingredients to keep customers happy. Most of these renovations in Bakery Blitz cost a pretty penny, but we have a few... | Read more »
How to manage your time in Bakery Blitz
It can be tricky, especially when you risk burning your kitchen to the ground if you forget a cake in the oven, so make sure to use these time management tricks to keep your bakery running smoothly. Don’t collect the money right away [Read more] | Read more »
Model 15 (Music)
Model 15 1.0 Device: iOS iPhone Category: Music Price: $29.99, Version: 1.0 (iTunes) Description: The Moog Model 15 App is the first Moog modular synthesizer and synthesis educational tool created exclusively for iPad, iPhone and... | Read more »
How to deal with wind in Angry Birds Act...
Angry Birds Action! is a physics-based puzzler in which you're tasked with dragging and launching birds around an obstacle-littered field to achieve a set objective. It's simple enough at first, but when wind gets introduced things can get pretty... | Read more »
How to get three stars in every level of...
Angry Birds Action! is, essentially, a pinball-style take on the pull-and-fling action of the original games. When you first boot it up, you'll likely be wondering exactly what it is you have to do to get a good score. Well, never fear as 148Apps... | Read more »
The beginner's guide to Warbits
Warbits is a turn-based strategy that's clearly inspired by Nintendo's Advance Wars series. Since turn-based strategy games can be kind of tricky to dive into, see below for a few tips to help you in the beginning. Positioning is crucial [Read... | Read more »
How to upgrade your character in Spellsp...
So you’ve mastered the basics of Spellspire. By which I mean you’ve realised it’s all about spelling things in a spire. What next? Well you’re going to need to figure out how to toughen up your character. It’s all well and good being able to spell... | Read more »
5 slither.io mash-ups we'd love to...
If there's one thing that slither.io has proved, it's that the addictive gameplay of Agar.io can be transplanted onto basically anything and it will still be good fun. It wouldn't be surprising if we saw other developers jumping on the bandwagon,... | Read more »
How to navigate the terrain in Sky Charm...
Sky Charms is a whimsical match-'em up adventure that uses creative level design to really ramp up the difficulty. [Read more] | Read more »
Victorious Knight (Games)
Victorious Knight 1.3 Device: iOS Universal Category: Games Price: $1.99, Version: 1.3 (iTunes) Description: New challenges awaits you! Experience fresh RPG experience with a unique combat mechanic, packed with high quality 3D... | Read more »

Price Scanner via MacPrices.net

Global Tablet Sales Slump Continues, iPad’s F...
Another miserable showing for the global slate tablet category in calendar Q1/16, with global tablet shipments falling another 1ten percent to 46.5 million units during the according to Strategy... Read more
Revel Systems to Showcase iPad POS Platform w...
Revel Systems, specialists in iPad Point of Sale management solution for brick-and-mortar retail, food businesses and more, today announced that it will showcase its innovative iPad Point of Sale... Read more
13-inch 2.5GHz MacBook Pro on sale for $999,...
B&H Photo has the 13″ 2.5GHz MacBook Pro on sale for $999 including free shipping plus NY sales tax only. Their price is $100 off MSRP. Read more
Apple refurbished 2015 iMacs available for up...
Apple now has a full line of Certified Refurbished 2015 21″ & 27″ iMacs available for up to $350 off MSRP. Apple’s one-year warranty is standard, and shipping is free. The following models are... Read more
Indian Smartphone Market Grows Annually by 12...
India’s smartphone market grew by 12 percent year-over-year, with 24.4 million units shipping in Q1 2016. The top five vendors stayed the same, with Samsung in the lead, followed by Micromax, Intex... Read more
Get Notifications When Your Friend’s Phone Ba...
Calgary, Canada based Stonelight Pictures has announced the release of Battery Share 1.0.1, its new utility for iOS 9 supported devices. The company notes that people are spending more time on their... Read more
11-inch 1.6GHz/128GB MacBook Air on sale for...
Amazon has the current-generation 11″ 1.6GHz/128GB MacBook Air (sku MJVM2LL/A) on sale for $749.99 for a limited time. Their price is $150 off MSRP, and it’s the lowest price available for this model... Read more
Price drops on clearance 2015 13-inch MacBook...
B&H Photo has dropped prices on clearance 2015 13″ MacBook Airs by up to $250. Shipping is free, and B&H charges NY sales tax only: - 13″ 1.6GHz/4GB/128GB MacBook Air (MJVE2LL/A): $799, $200... Read more
Mac minis on sale for up to $100 off MSRP
B&H Photo has Mac minis on sale for up to $100 off MSRP including free shipping plus NY sales tax only: - 1.4GHz Mac mini: $449 $50 off MSRP - 2.6GHz Mac mini: $649 $50 off MSRP - 2.8GHz Mac mini... Read more
13-inch Retina MacBook Pros on sale for up to...
B&H Photo has 13″ Retina MacBook Pros on sale for $130-$200 off MSRP. Shipping is free, and B&H charges NY tax only: - 13″ 2.7GHz/128GB Retina MacBook Pro: $1169 $130 off MSRP - 13″ 2.7GHz/... Read more

Jobs Board

Restaurant Manager (Neighborhood Captain) - A...
…in every aspect of daily operation. WHY YOU'LL LIKE IT: You'll be the Big Apple . You'll solve problems. You'll get to show your ability to handle the stress and Read more
Simply Mac *Apple* Specialist- Service Repa...
Simply Mac is the largest premier retailer of Apple products in the nation. In order to support our growing customer base, we are currently looking for a driven Read more
Restaurant Manager (Neighborhood Captain) - A...
…in every aspect of daily operation WHY YOU LL LIKE IT You ll be the Big Apple You ll solve problems You ll get to show your ability to handle the stress and Read more
*Apple* Retail - Multiple Positions (US) - A...
Job Description:SalesSpecialist - Retail Customer Service and SalesTransform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Restaurant Manager (Neighborhood Captain) - A...
…in every aspect of daily operation. WHY YOU'LL LIKE IT: You'll be the Big Apple . You'll solve problems. You'll get to show your ability to handle the stress and Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.