TweetFollow Us on Twitter

Mar 89 Letters
Volume Number:5
Issue Number:3
Column Tag:Letters

Letters

By David E. Smith, Editor & Publisher, MacTutor

INIT29 & Hpat Virsus Wanted!

Steve Sequist is requesting an infected disk with the new INIT29 and Hpat (nVir type) virus so he can update last month's Security Patrol anit-virus program to detect and destroy them. If you have one or both, please send an infected disk, clearly marked with a skull and crossbones, to MacTutor, PO Box 400, Placentia, CA 92670, attn: Virus! -Ed

Watch Cursor Revisited

Jan Eugenides

Waterbury Center, VT

David Stoops’ Animated Cursors from the December issue was interesting, but it had two deficiencies:

1) It was hard-coded for eight cursors, instead of obtaining the real number of cursors from the ‘acur’ resource,

2) It used SetUpA5 and RestoreA5, which should no longer be used.

I recoded the example in MPW C 3.0b1, with the modifications, and here is the result. I also changed to an ‘acur’ resource with an ID of 128, so as not to conflict with any system resources. The Rez source code for the watch ‘acur’ and the associated cursors are as follows:

/* 1 */

#include <Types.h>
#include <Resources.h>
#include <QuickDraw.h>
#include <OSUtils.h>
#include <Retrace.h>
#include <Memory.h>
#include <ToolUtils.h>
#include <Strings.h>
#include <Errors.h>

typedef struct {
 short  numCurs; /*number of cursor “frames” */
 short  whichCur;/*used as “frame” counter*/
 CursHandle Curs[1]; /*can actually be any number of cursors here*/
 }acur;
typedef acur*acurPtr,**acurHandle;

static acurHandleCurList;
static VBLTask   VBL;

pascal void AnimateWatch()  /*the VBL routine*/
{
long    oldA5;

oldA5 = SetCurrentA5();
if((*CurList)->whichCur >= (*CurList)->numCurs-1 )
 (*CurList)->whichCur = 0;
else
 (*CurList)->whichCur ++;
SetCursor(*((*CurList)->Curs[(*CurList)->whichCur]));
VBL.vblCount = 10;
SetA5(oldA5);
}

InitWatch()
{
short   curCount;

CurList = (acurHandle)GetResource(‘acur’,128);
for(curCount = 0; curCount < (*CurList)->numCurs; curCount++)
 (*CurList)->Curs[curCount] = GetCursor(HiWord((long)(*CurList)->Curs[curCount]));
(*CurList)->whichCur = 0;
}
StartWatch()
{
OSErr   err;

VBL.qType = vType;
VBL.vblAddr = (VBLProcPtr)AnimateWatch;
VBL.vblCount = 10;
VBL.vblPhase = 0;
err = VInstall((QElemPtr)&VBL);
}

StopWatch()
{
OSErr err;

err = VRemove((QElemPtr)&VBL);
}
/* 2 */

#include “types.r”

data ‘acur’ (128, locked, preload) {
 $”00 08 00 00 01 00 00 00 01 01 00 00 01 02 00 00"
 $”01 03 00 00 01 04 00 00 01 05 00 00 01 06 00 00"
 $”01 07 00 00"
};
resource ‘CURS’ (263, locked, preload) {
 $”3F 00 3F 00 3F 00 3F 00 40 80 80 40 90 40 88 60"
 $”9C 60 80 40 80 40 40 80 3F 00 3F 00 3F 00 3F”,
 $”3F 00 3F 00 3F 00 3F 00 7F 80 FF C0 FF C0 FF C0"
 $”FF C0 FF C0 FF C0 7F 80 3F 00 3F 00 3F 00 3F”,
 {8, 8}
};
resource ‘CURS’ (262, locked, preload) {
 $”3F 00 3F 00 3F 00 3F 00 40 80 80 40 80 40 80 60"
 $”BC 60 80 40 80 40 40 80 3F 00 3F 00 3F 00 3F”,
 $”3F 00 3F 00 3F 00 3F 00 7F 80 FF C0 FF C0 FF C0"
 $”FF C0 FF C0 FF C0 7F 80 3F 00 3F 00 3F 00 3F”,
 {8, 8}
};
resource ‘CURS’ (261, locked, preload) {
 $”3F 00 3F 00 3F 00 3F 00 40 80 80 40 80 40 80 60"
 $”9C 60 88 40 90 40 40 80 3F 00 3F 00 3F 00 3F”,
 $”3F 00 3F 00 3F 00 3F 00 7F 80 FF C0 FF C0 FF C0"
 $”FF C0 FF C0 FF C0 7F 80 3F 00 3F 00 3F 00 3F”,
 {8, 8}
};
resource ‘CURS’ (260, locked, preload) {
 $”3F 00 3F 00 3F 00 3F 00 40 80 80 40 80 40 80 60"
 $”9C 60 84 40 84 40 40 80 3F 00 3F 00 3F 00 3F”,
 $”3F 00 3F 00 3F 00 3F 00 7F 80 FF C0 FF C0 FF C0"
 $”FF C0 FF C0 FF C0 7F 80 3F 00 3F 00 3F 00 3F”,
 {8, 8}
};
resource ‘CURS’ (259, locked, preload) {
 $”3F 00 3F 00 3F 00 3F 00 40 80 80 40 80 40 80 60"
 $”9C 60 82 40 80 40 40 80 3F 00 3F 00 3F 00 3F”,
 $”3F 00 3F 00 3F 00 3F 00 7F 80 FF C0 FF C0 FF C0"
 $”FF C0 FF C0 FF C0 7F 80 3F 00 3F 00 3F 00 3F”,
 {8, 8}
};
resource ‘CURS’ (258, locked, preload) {
 $”3F 00 3F 00 3F 00 3F 00 40 80 80 40 80 40 80 60"
 $”9F 60 80 40 80 40 40 80 3F 00 3F 00 3F 00 3F”,
 $”3F 00 3F 00 3F 00 3F 00 7F 80 FF C0 FF C0 FF C0"
 $”FF C0 FF C0 FF C0 7F 80 3F 00 3F 00 3F 00 3F”,
 {8, 8}
};
resource ‘CURS’ (257, locked, preload) {
 $”3F 00 3F 00 3F 00 3F 00 40 80 80 40 81 40 82 60"
 $”9C 60 80 40 80 40 40 80 3F 00 3F 00 3F 00 3F”,
 $”3F 00 3F 00 3F 00 3F 00 7F 80 FF C0 FF C0 FF C0"
 $”FF C0 FF C0 FF C0 7F 80 3F 00 3F 00 3F 00 3F”,
 {8, 8}
};
resource ‘CURS’ (256, locked, preload) {
 $”3F 00 3F 00 3F 00 3F 00 40 80 84 40 84 40 84 60"
 $”9C 60 80 40 80 40 40 80 3F 00 3F 00 3F 00 3F”,
 $”3F 00 3F 00 3F 00 3F 00 7F 80 FF C0 FF C0 FF C0"
 $”FF C0 FF C0 FF C0 7F 80 3F 00 3F 00 3F 00 3F”,
 {8, 8}
};

Animated Cursors Again

Erny Tontlinger

Steinfort, Luxembourg

Here are some comments to David Stoops’ Animated Cursors from the December 1988 Letters Column.

There is an error in the procedure InitWatch. The cursor id should be replaced by the cursor handle in the loop this:

/* 3 */

Watch[watchcount] := GetCursor(HiWord(longint(Watch[watchcount])));

The correct structure of a ‘acur’ resource is:

/* 4 */

acur = record
 frames: integer; {Number of frames(cursors) }
 whichWatch : integer;
 Watch : array[1..99] of CursHandle
 { size depends on frames }
end;

Then instead of using a fixed number of eight cursors, use Watch^^.frames, which happens to be eight for the Finder.

The ‘acur’ and ‘CURS’ resources should be locked, otherwise the VBL task runs into troubles with the memory Manager. The Finder uses the ‘CURS’ id 4 (classic watch cursor), which in the System file is not locked. This cursor is also in ROM, from the Mac Plus machines on, so it would be good to set RomMapInsert to mapTrue before calling GetCursor.

SetUpA5 and RestoreA5 might not work as expected under MultiFinder. The value of A5 should be placed in a position, other than CurrentA5 in low memory globals, where the application can find it from within the VBL task. See “Programmer’s Guide to MultiFinder” (APDA# KMB017) the chapter “The A5 world/VBL tasks”.

Now something different. Why is it so difficult to print READABLE program listing in MacTutor? Your desktop publishing program seems to have problems with regular spaced tab positions. Anyhow I appreciate MacTutor very much. [Basically, we convert the source into WriteNow in a 3 1/2" width single column with tabs set at every eighth of an inch. Then we place it into PageMaker. Here is where a number of problems occur as you surmised. PageMaker doesn't exactly import tab information correctly and we have to manually fix it. -Ed]

More Animated Watch Cursors

Rob Terrell

Chapel Hill, NC

In the December issue, you printed a letter that showed how to animate the watch cursor as a VBL task, which I thought was strange since a few issues back you printed another letter that gave a very good reason not to: a VBL task can go on and on while the application has crashed, and the poor user will be stuck thinking everything is okay.

A better way to implement the animated watch is through a unit that just takes a single call to increment the cursor. Support for this exists in TML Pascal II; for those not fortunate as to own TML, here’s a unit that does essentially the same thing:

{5}

Unit WatchItSpin;
(*Make sure you have copied the ‘acur’ and ‘CURS’ *)
(* resources from the Finder into your application *)
(* ResEdit is quite handy for this *)

Interface

Uses MemTypes, QuickDraw, OSintf, Toolintf;

type
 aCur = record
 whichWatch : longint;
 watch : array[1..8] of CursHandle;
 end;
 acurPtr = ^ acur;
 acurHandle = ^acurPtr;
var
 currentWatch : integer;
 WatchList : acurHandle;

Procedure InitSpinner;
Procedure SpinWatch;

Implementation

Procedure InitSpinner;
var
 count : integer;
begin
 watchList := acurHandle(GetResource(‘acur’,0));
 with watchList^^ do begin
 for count := 1 to 8 do
 Watch[count] := GetCursor(HiWord(longint( Watch[count])));
 whichWatch := 0;
 end;
end; (* InitSpinner *)

Procedure SpinWatch;
begin
 with WatchList^^ do begin
 if whichWatch >= 8 then whichWatch := 1
 else whichWatch := whichWatch + 1;
 SetCursor(Watch[whichWatch]^^);
 end;
end; (* SpinWatch *)
end.

Most of this code was simply taken from David Stoops’ letter. However, to use this, you call InitSpinner when you initialize everything else at the beginning of your program; then you call SpinWatch each time through a loop or time-consuming process to increment it. Not quite as nice as having a VBL take care of it, but this way, if you crash, the hands will stop.

Correction to CompareString

Steve Brecher

Sunnyvale, CA

In John S. Stokes III's CompareString routine (Jan 89 Letters), use of the Ext.W instruction introduces an error:

 Move.B (A0),D1  ; length of the first string
 Ext..W D1; dbra uses word

Ext.W propagates the value in bit 15 of the register through bits 16..31. Therefore, it will not have the desired effect of clearing bits 8..15. Ext.B would not work either for cases in which the string length is greater than 127,i.e. , negative considered as a signed byte; in such cases Ext.B would set bits 8..15, making the unsigned word value very large. To convert an unsigned byte value to a word in a register, first clear the word and then move the byte into it:

;6

 Clr.W  D1
 Move.B (A0),D1

Often programmers will write MoveQ #0,Dn instead of Clr.W Dn when the value in the upper word of the register either needs to be cleared also or is not of concern. MoveQ is always a longword operation.

A corrected CompareString would look like this:

;7

; A0  --> Pascal string 1
; A1 --> Pascal string 2
; Returns D0.L=1 if equal, 0 if not equal
; Alters A0-A1

CompareString:
 MoveQ  #0,D0
 Move.B (A0),D0  ;gross len - 1
@0 Cmp.B(A0)+,(A1)+ ;loop until...
 DBne D0,@0 ;...not equal or end
 Seq  D0;D0 := $FF if equal, else 0
 Neg.B  D0;D0 := 1 if equal, else 0
 Rts

The Move.B instruction puts the length byte of string 1 into D0. We want to compare the entire string structures, including their length bytes. The length of the entire structure--the gross length--of a string is the the number of text bytes, plus one for the length byte. For a DBxx instruction, we want the gross length - 1, which is just the value of the length byte.

We use the DBne instruction to control the loop. DBxx will branch to the start of the loop if either the test condition (in this case, “ne”) is false or the loop count is exhausted. Thus DBxx should be read as “branch until xx or counter expired.” When control falls through the DBne, we use the Seq instruction to condition D0 to the result of the last Cmp.B; DBxx instructions do not alter the condition codes. If the strings (including their lengths) are equal, the result of the last Cmp.B will be “eq” and the DBne will have not branched because the D1 counter expired. If the length bytes or contents of the strings are not equal, the last Cmp.B result will have been “ne” and the DBne will have not branched because its “until” condition was met.

[Steve Brecher is a long time friend of MacTutor. We welcome his comments and hope to hear more from him in the coming months. -Ed]

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Sketch 44.1 - Design app for UX/UI for i...
Sketch is an innovative and fresh look at vector drawing. Its intentionally minimalist design is based upon a drawing space of unlimited size and layers, free of palettes, panels, menus, windows, and... Read more
BetterTouchTool 2.260 - Customize Multi-...
BetterTouchTool adds many new, fully customizable gestures to the Magic Mouse, Multi-Touch MacBook trackpad, and Magic Trackpad. These gestures are customizable: Magic Mouse: Pinch in / out (zoom... Read more
Chromium 59.0.3071.115 - Fast and stable...
Chromium is an open-source browser project that aims to build a safer, faster, and more stable way for all Internet users to experience the web. Version 59.0.3071.115: This update has no Flash plug... Read more
SyncTwoFolders 2.2.3 - Syncs two user-sp...
SyncTwoFolders simply synchronizes two folders. It supports synchronization across mounted network drives and it is a possibility to run a simulation showing in a log what will be done. Please visit... Read more
Myriad 4.1 - $79.00
Myriad is, simply put, one of the best audio batch processors. Totally redesigned, it looks beautiful and delivers incredible performance. Let Myriad do the heavy lifting while you get back to doing... Read more
Suitcase Fusion 7 18.2.4 - Font manageme...
Suitcase Fusion 7 is the creative professional's font manager. Every professional font manager should deliver the basics: spectacular previews, powerful search tools, and efficient font organization... Read more
SoftRAID 5.6.1 - High-quality RAID manag...
SoftRAID allows you to create and manage disk arrays to increase performance and reliability. SoftRAID allows the user to create and manage RAID 4 and 5 volumes, RAID 1+0, and RAID 1 (Mirror) and... Read more
BetterTouchTool 2.25 - Customize Multi-T...
BetterTouchTool adds many new, fully customizable gestures to the Magic Mouse, Multi-Touch MacBook trackpad, and Magic Trackpad. These gestures are customizable: Magic Mouse: Pinch in / out (zoom... Read more
Google Chrome 59.0.3071.115 - Modern and...
Google Chrome is a Web browser by Google, created to be a modern platform for Web pages and applications. It utilizes very fast loading of Web pages and has a V8 engine, which is a custom built... Read more
Google Chrome 59.0.3071.115 - Modern and...
Google Chrome is a Web browser by Google, created to be a modern platform for Web pages and applications. It utilizes very fast loading of Web pages and has a V8 engine, which is a custom built... Read more

Latest Forum Discussions

See All

Ravenscroft 275 Piano (Music)
Ravenscroft 275 Piano 1.0.0 Device: iOS Universal Category: Music Price: $35.99, Version: 1.0.0 (iTunes) Description: Experience the splendor of a Ravenscroft Grand with the most realistic sounding piano ever created for iOS. Launch... | Read more »
This War of Mine gets a new ending and m...
This War of Mine just got a big new update, featuring free DLC that adds a new ending to the game, among other exciting changes. The update is celebrating the game's two-year release anniversary. Apart from the new ending, which will be quite... | Read more »
Summon eight new heroes in Fire Emblem H...
Nintendo keeps coming at us with Fire Emblem Heroes updates, and it doesn't look like that trend is stopping anytime soon. The folks behind the game have just announced the new War of the Clerics Voting Gauntlet, expected to start next Tuesday. [... | Read more »
The best deals on the App Store this wee...
iOS publishers are pulling out all the stops this week -- there's a huge number of seriously great games at discounted prices this week. Let's not waste any time and get right down to business. [Read more] | Read more »
The House of da Vinci (Games)
The House of da Vinci 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: Enter The House of Da Vinci, a new must-try 3D puzzle adventure game. Solve mechanical puzzles, discover hidden... | Read more »
Solve the disappearance of history’s gre...
Blue Brain Games invites you to indulge in an immersive hands-on 3D puzzle adventure in similar vein to The Room series, with its debut release The House of Da Vinci. Set during the historic period of the Italian Renaissance (when Leonardo himself... | Read more »
Age of Rivals (Games)
Age of Rivals 3.3 Device: iOS Universal Category: Games Price: $.99, Version: 3.3 (iTunes) Description: Deep civilization-building strategy in a fast-paced card game! | Read more »
Panthera Frontier (Games)
Panthera Frontier 1.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0 (iTunes) Description: | Read more »
Angry Birds Evolution beginner's gu...
Angry Birds changes things up a fair bit in its latest iteration, Angry Birds Evolution. The familiar sling-shot physics mechanics are still there, but the game now features team-based gameplay, RPG elements, and a new top-down view. With all of... | Read more »
Sega Forever is for the retro game fans
Sega is launching a new retro games service titled Sega Forever, in a move that's sure to delight games enthusiasts with a bit of nostalgia. Sega's releasing five classic games for free. The titles include Sonic the Hedgehog, Phantasy Star II,... | Read more »

Price Scanner via MacPrices.net

Apple Releases iOS 11 Public Beta; How To Get...
The official release of Apple’s latest mobile operating system iOS 11 is vaguely slated for the fall, but as of June 26, ordinary users can download an iOS 11 public beta. To download the iOS 11... Read more
Extend Life of MacBook Pro Retina 2.0TB With...
MacSales.com/Other World Computing has announced availability of the new OWC 2.0TB Aura Pro Solid State Drive for mid-2012 to early 2013 Apple MacBook Pro with Retina display. One of the fastest... Read more
BBEdit SummerFest 2017 Discount Ends Friday,...
You can get 20% off BBEdit for a limited time in Bare Bones Software’s http://www.eastgate.com/Tinderbox/Specials/SummerFest.html?mc_cid=f2101ca260&mc_eid=[UNIQID]SummerFest 2017 sale and... Read more
Use Apple’s Education discount to save up to...
Purchase a new Mac using Apple’s Education discount, and take up to $300 off MSRP. All teachers, students, and staff of any educational institution qualify for the discount. Shipping is free: - 15″ 2... Read more
Clearance 27-inch 3.3GHz 5K iMac available fo...
Amazon clearance 27″ 3.3GHz 5K iMacs (MK482LL/A) available for $1799.90 including free shipping. Their price is $500 off original MSRP, and it’s the lowest price available for this model from any... Read more
13-inch 1.8GHz/256GB MacBook Air on sale for...
B&H Photo has the updated 2017 13″ 1.8GHz/256GB MacBook Air (MQD42LL/A) in stock and on sale for $1129 including free shipping plus NY & NJ tax only. Their price is $70 off MSRP. Read more
27-inch 3.4GHz iMac on sale for $1699, save $...
B&H Photo has the new 2017 27″ 3.4GHz iMac (MNE92LL/A) in stock and on sale for $1699 including free shipping plus NY & NJ sales tax only. Their price is $100 off MSRP. Read more
21-inch 2.3GHz iMac on sale for $1049, save $...
B&H Photo has the new 2017 21″ 2.3GHz iMac (MMQA2LL/A) in stock and on sale for $1049 including free shipping plus NY & NJ tax only. Their price is $50 off MSRP. Read more
ABBYY TextGrabber 6 for iOS Implements Instan...
ABBYY has announced the release of TextGrabber 6.0.0, an important feature update to the company’s productivity app developed for iOS and Android devices. TextGrabber 6.0 now offers Real-Time... Read more
vPhone, First Smartphone That Can’t Be Lost,...
Austin, Texas based Hypori has introduced the vPhone, a virtual smartphone that affords every business user the benefits of separate work and personal phones, conveniently delivered on a single... Read more

Jobs Board

*Apple* News Product Marketing Mgr., Publish...
…organizational consensus on strategy and vision for publisher tools, authoring, and Apple News Format.Carries this strategy and vision across the organization to Read more
*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Security Data Analyst - *Apple* Information...
…data sources need to be collected to allow Information Security to better protect Apple employees and customers from a wide range of threats.Act as the subject matter Read more
Lead *Apple* Solutions Consultant - Apple I...
…integrity, and trust.Success Metrics/Key Performance Indicators:Quantitative* Year over Year growth in Apple Product and Beyond the Box sales in the assigned Point of Read more
*Apple* Solutions Consultant till v%u00E5r...
…ethics, integrity, and trust.Success Metrics/Key Performance Indicators:QuantitativeYear over Year growth in Apple Product and Beyond the Box sales in the assigned Point Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.