TweetFollow Us on Twitter

Time Retrieval
Volume Number:5
Issue Number:1
Column Tag:Basic School

Related Info: Time Manager

Time Retrieval and Storage Techniques

By Dave Kelly, MacTutor Editorial Board

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

Time Retrieval and Storage Techniques

It’s only a matter of time. Anybody see the ad for the MacTutor of the future in the November, 1988 MacTutor? The ad may sound like a joke about the 100th anniversary of MacTutor, but some of the “future” has already been invented. I did some thought on the subject of the Basic School column described in the ad, which is also the title of this column. There are two basic subjects implied by the title, time retrieval and time storage.

From a philosophical point of view you may ask, how can time be saved or retrieved? Looking at the answer from that perspective would lead us to a discussion of Einstein and his theory of relativity which is beyond the scope and intent of this column. Instead let’s look at some ways which we can use time to our advantage and see how storage and retrieval fits into the scheme of things.

From a user level on the Macintosh there is one time retrieval/storage mechanism that is accessible to all “the rest of us”. The example I refer to is the Alarm mechanism built into the clock chip. The date and time setting is copied (“retrieved”) at system startup from the clock chip into its own low-memory location. It’s stored there as the number of seconds since midnight, January 1, 1904, and is updated every second. The range of the clock chip is from January 1, 1904 through February 6, 2040 (does that mean that 51 years from now I’ll need to replace my clock chip?). The low-memory location can be access by your program. BASIC (every brand) includes its own time retrieval command. In True Basic the TIME and TIME$ functions are provided. TIME returns the number of seconds since midnight in tenths of seconds. The TIME$ function returns a string that contains the time as measured by the 24-hour clock with resolution in seconds. ZBasic and MS QuickBASIC uses the TIMER function which returns the seconds since midnight (similar to the True Basic TIME function) and TIME$ which works the same as in True Basic. The problem is that the TIMER function does not provide enough resolution. At least the True Basic TIME function provided tenths of seconds or better resolution. Since we know that other languages are able to access the time in greater resolution, we may use the same function (ROM) to retrieve the time in greater resolution. This is especially important for benchmark tests where two compiled programs are being timed and the difference is tenths of seconds or better. In benchmarks that have been done in the past, sometimes the TIME function was used and there was rounding off to either 0 or 1 second. A program running in 0 seconds is absurd, but that was the best we could do with MS Basic at the time. QuickBASIC and ZBasic both allow access to the TickCount call (Macintosh ROM). In QuickBASIC a typical benchmark might be implemented such as:

Figure 1. The Time Machine

First initialize the ToolBox routine:

TOOLBOX “I”

This must be used before any other ToolBox statement in the program. Now define a sub program or routine that can be called to replace the other time functions usually used in the benchmark.

SUB Tick (Count&) STATIC
TrapNo% = &HA975
Count& = 0&  : ‘Define the variable
ToolBox “L”, TrapNo%, Count&
END SUB

Now call Tick(Count&) whenever you need the time. A tick is one-sixtieth of a second, enough for the tenth of a second accuracy provided by True BASIC’s function. In ZBasic it is even easier to call TickCount. In ZBasic just use the function directly:

Count&=FN TICKCOUNT

As you can see, accessing real time is really the simple part of the job. Accessing stored time is another aspect. I’ll leave the subject of how the stored time became stored for later except to say that the Parameter RAM also stores the alarm setting. You can set the alarm with the Alarm Clock DA (included with your system software).

The Analog Alarm Clock program included here demonstrates how you can retrieve the stored alarm time from the low-memory area. The Alarm time is stored at $200. The getAlarm routine retrieves the time by peeking at memory directly. The result is then converted to date information via the secs2date toolbox routine. The Analog Clock program reveals some problems. The date conversion library routines are used to convert seconds to dates and dates to seconds. Secs2Date works fine, but there is a problem with the Date2Secs routine. This means that the Date2Secs routine must be called a different way. Fortunately, QuickBASIC provides the ToolBox call which allows you to make ROM calls yourself. The following lines replace the Date2Secs library routine:

ToolBox “I”

...   (Don’t forget to initialize the toolbox)


TrapNo%=&HA9C7
ToolBox “R”, TrapNo%, ReturnArray&(0),VARPTR(DtRec%(0))
Al&=ReturnArray&(2)

It’s unfortunate that we have to go through that trouble, but that’s just the way it goes. I confess it took awhile before I realized that I wasn’t going to be able to get it to work without the ToolBox library call.

In the program, alarm time is taken from parameter RAM and then it’s updated when changed when the alarm is turned on. Be careful when poking around the parameter RAM. If the wrong parameter gets changed you may have to Zap the parameter RAM to get started. You can do this by removing your MacPlus battery for a few minutes when your power is off or by holding down command-option when opening the control panel on newer Mac systems.

Flashing the menu bar like the Alarm Clock DA does will be left for another day. Anybody know how to do that from Basic? What I’m not sure of is where the alarm status is stored. Happy New Year!

‘Analog Alarm Clock Program
‘©1989 MacTutor
‘by Dave Kelly

DIM DtRec%(6),CenterRect%(3),pattern%(3)
ToolBox “I”
DIM ReturnArray&(5)
GOSUB getAlarm
false=0:true=NOT false
PI=3.14159

‘Set up menus
MENU 1,0,1,”File”
MENU 1,1,1,”Turn Alarm On ”
MENU 1,2,0,”-”
MENU 1,3,1,”Quit”
CmdKey 1,3,”Q”

‘ Get Screen size
sheight=SYSTEM(6)
swidth=SYSTEM(5)
WINDOW 1,”Analog Alarm Clock”,(4,44)-(swidth-4,sheight-4),6

‘Find the center of the window, centerx%,centery%
‘ This should work with any size of screen
wheight%=WINDOW(3)
wwidth%=WINDOW(2)
centerx%=wwidth%/2
centery%=wheight%/2
circledia=centery%-25
GOSUB SetupClock
ON MENU GOSUB MenuEvent
ON DIALOG GOSUB DialogEvent
DIALOG ON:MENU ON

Loop:
forecolor 33:’ change color to black
t$=TIME$:’ Get the current time and separate into variables
hour$=LEFT$(t$,2)
Min$=MID$(t$,4,2)
Sec$=RIGHT$(t$,2)
H=VAL(hour$):M=VAL(Min$):S=VAL(Sec$)
IF H>12 THEN H=H-12
H=H+M/60

‘ Compute the angles for each hand of the clock
SecAngle=(360-S*6)*PI/180
MinAngle=(360-M*6)*PI/180
HAngle=(360-H*30)*PI/180

‘Draw the second hand
CALL MOVETO (centerx%,centery%)
ypoint=(circledia*COS(SecAngle))*.98
xpoint=(circledia*SIN(SecAngle))*.98
CALL LINE (-xpoint,-ypoint)
IF SecAngle<>OldSec THEN
    CALL MOVETO (centerx%,centery%)
    CALL PENMODE (11)
    ypoint=(circledia*COS(OldSec))*.98
    xpoint=(circledia*SIN(OldSec))*.98
    CALL LINE (-xpoint,-ypoint)
    CALL PENMODE(8)
END IF

‘Draw the minute hand
CALL PENSIZE(2,2)
CALL MOVETO (centerx%,centery%)
ypoint=(circledia*COS(MinAngle))*.9
xpoint=(circledia*SIN(MinAngle))*.9
CALL LINE (-xpoint,-ypoint)
IF MinAngle<>OldMin THEN
    CALL MOVETO (centerx%,centery%)
    CALL PENMODE (11)
    ypoint=(circledia*COS(OldMin))*.9
    xpoint=(circledia*SIN(OldMin))*.9
    CALL LINE (-xpoint,-ypoint)
    CALL PENMODE(8)
END IF

‘Draw the hour hand
CALL PENSIZE(4,4)
CALL MOVETO (centerx%,centery%)
ypoint=(circledia/2*COS(HAngle))
xpoint=(circledia/2*SIN(HAngle))
CALL LINE (-xpoint,-ypoint)
IF MinAngle<>OldMin THEN
    CALL MOVETO (centerx%,centery%)
    CALL PENMODE (11)
    ypoint=(circledia/2*COS(OldH))
    xpoint=(circledia/2*SIN(OldH))
    CALL LINE (-xpoint,-ypoint)
    CALL PENMODE(8)
END IF
CALL PENSIZE(1,1)

forecolor 205:’ Change color to red
LOCATE 1,1:PRINT “AlarmTime: “;AlarmTime$
forecolor 33:’ Change color to black
LOCATE 2,1:PRINT “Current Time: “;t$
CALL TEXTMODE(0)
OldT$=t$:OldSec=SecAngle:OldMin=MinAngle:OldH=HAngle
CALL FILLOVAL(VARPTR(CenterRect%(0)),VARPTR(pattern%(0)))
IF Alrm=false THEN
    forecolor 273
    LOCATE 3,1:PRINT “Alarm is off”:GOTO Loop
END IF
forecolor 341:’Change color to Green
LOCATE 3,1:PRINT “Alarm is on “
‘Sound the alarm if time is up!
IF t$=AlarmTime$ THEN
    BEEP:BEEP:BEEP
    LOCATE 4,1:PRINT “Alarm event occurred”
END IF
GOTO Loop
DIALOG OFF

SetupClock:’ Set up the face of the clock
activewindow=WINDOW(0)
WINDOW OUTPUT 1
CALL TEXTSIZE(14)
CALL MOVETO(centerx%-8,centery%-circledia-4):PRINT “12”;
CALL MOVETO(centerx%-8,centery%+circledia+20):PRINT “ 6”;
CALL MOVETO(centerx%-circledia-20,centery%+7):PRINT “9”;
CALL MOVETO(centerx%+circledia+10,centery%+7):PRINT “3”;
PSET (centerx%,centery%)
forecolor 205:’ Change color to red
CALL PENSIZE(2,2)
CIRCLE (centerx%,centery%),circledia
CALL PENSIZE(1,1)
SetRect CenterRect%(0),centerx%-5,centery%-5,centerx%+5,centery%+5
forecolor 33:’ Change color to black
SetRect pattern%(0),&HFFFF,&HFFFF,&HFFFF,&HFFFF
CALL FILLOVAL(VARPTR(CenterRect%(0)),VARPTR(pattern%(0)))
WINDOW OUTPUT activewindow
RETURN

DialogEvent:
d=DIALOG(0)
SELECT CASE d
    CASE 1
        IF DIALOG(1)=1 THEN editwindow=true
    CASE 4
        GOTO Quit
    CASE 5
        IF DIALOG(5)=1 THEN GOSUB SetupClock
    CASE ELSE
END SELECT
RETURN

MenuEvent:
menunumber=MENU(0)
menuitem=MENU(1)
MENU
IF menunumber=1 THEN
    IF menuitem=1 THEN GOSUB SetAlarm
    IF menuitem=3 THEN Quit
END IF
RETURN

SetAlarm:’ Set the alarm
Alrm=NOT Alrm
DoSet:
IF Alrm THEN
    MENU 1,1,1,”Turn Alarm Off”
    WINDOW 2,””,(50,50)-(250,150),2
    LOCATE 2,1:PRINT “Alarm Time:”
    IF AlarmTime$=”” THEN AlarmTime$=TIME$
    EDIT FIELD 1,AlarmTime$,(100,17)-(165,32),1
    BUTTON 1,1,”OK”,(40,45)-(170,75),1
    editwindow=false
    WHILE editwindow=false
    WEND
    AlarmTime$=EDIT$(1)
    a$=””:i=1
    WHILE MID$(AlarmTime$,i,1)<>”:”
        a$=a$+MID$(AlarmTime$,i,1)
        i=i+1
    WEND
    Ahour=VAL(a$)
    IF Ahour>24 OR Ahour<0 THEN GOTO DoSet
    a$=””
    i=i+1
    WHILE MID$(AlarmTime$,i,1)<>”:”
        a$=a$+MID$(AlarmTime$,i,1)
        i=i+1
    WEND
    Amin=VAL(a$)
    IF Amin>59 OR Amin<0 THEN GOTO DoSet
    a$=””
    i=i+1
WHILE i<=LEN(AlarmTime$)
        a$=a$+MID$(AlarmTime$,i,1)
        i=i+1
WEND
Asec=VAL(a$)
IF Asec>59 OR Asec<0 THEN GOTO DoSet
a$=””
IF Ahour<10 THEN a$=”0"+STR$(Ahour) ELSE a$=STR$(Ahour)
a$=a$+”:”
IF Amin<10 THEN a$=a$+”0"+STR$(Amin) ELSE a$=a$+STR$(Amin)
a$=a$+”:”
IF Asec<10 THEN a$=a$+”0"+STR$(Asec) ELSE a$=a$+STR$(Asec)
AlarmTime$=””
FOR i=1 TO LEN(a$)
    IF MID$(a$,i,1)<>” “ THEN AlarmTime$=AlarmTime$+MID$(a$,i,1)
NEXT i
DtRec%(3)=Ahour
DtRec%(4)=Amin
DtRec%(5)=Asec
‘Call Date2secs routine (QuickBASIC Date2secs does not work right)
TrapNo%=&HA9C7
ToolBox “R”, TrapNo%, ReturnArray&(0),VARPTR(DtRec%(0))
Al&=ReturnArray&(2)
POKEL &H200, Al&
    WINDOW CLOSE 2
ELSE
    TEXTMODE (0):LOCATE 2,1:PRINT”                                   
     “
    MENU 1,1,1,”Turn Alarm On ”
END IF
RETURN

getAlarm:’ Retrieve
Al&= PEEKL(&H200)
secs2Date Al&,DtRec%(0)
a$=””
IF DtRec%(3)<10 THEN a$=”0"+STR$(DtRec%(3)) ELSE a$=STR$(DtRec%(3))
a$=a$+”:”
IF DtRec%(4)<10 THEN a$=a$+”0"+STR$(DtRec%(4)) ELSE a$=a$+STR$(DtRec%(4))
a$=a$+”:”
IF DtRec%(5)<10 THEN a$=a$+”0"+STR$(DtRec%(5)) ELSE a$=a$+STR$(DtRec%(5))
AlarmTime$=””
FOR i=1 TO LEN(a$)
    IF MID$(a$,i,1)<>” “ THEN AlarmTime$=AlarmTime$+MID$(a$,i,1)
NEXT i
RETURN

Quit:
WINDOW CLOSE 1
END

 
AAPL
$95.60
Apple Inc.
-2.55
MSFT
$43.16
Microsoft Corpora
-0.42
GOOG
$571.60
Google Inc.
-15.82

MacTech Search:
Community Search:

Software Updates via MacUpdate

OneNote 15.2 - Free digital notebook fro...
OneNote is your very own digital notebook. With OneNote, you can capture that flash of genius, that moment of inspiration, or that list of errands that’s too important to forget. Whether you’re at... Read more
iStat Menus 4.22 - Monitor your system r...
iStat Menus lets you monitor your system right from the menubar. Included are 8 menu extras that let you monitor every aspect of your system. Some features: CPU -- Monitor cpu usage. 7 display... Read more
Ember 1.8 - Versatile digital scrapbook....
Ember (formerly LittleSnapper) is your digital scrapbook of things that inspire you: websites, photos, apps or other things. Just drag in images that you want to keep, organize them into relevant... Read more
OmniPlan 2.3.6 - Robust project manageme...
With OmniPlan, you can create logical, manageable project plans with Gantt charts, schedules, summaries, milestones, and critical paths. Break down the tasks needed to make your project a success,... Read more
Command-C 1.1.1 - Clipboard sharing tool...
Command-C is a revolutionary app which makes easy to share your clipboard between iOS and OS X using your local WiFi network, even if the app is not currently opened. Copy anything (text, pictures,... Read more
Knock 1.1.7 - Unlock your Mac by knockin...
Knock is a faster, safer way to sign in. You keep your iPhone with you all the time. Now you can use it as a password. You never have to open the app -- just knock on your phone twice, even when it's... Read more
Mellel 3.3.6 - Powerful word processor w...
Mellel is the leading word processor for OS X and has been widely considered the industry standard since its inception. Mellel focuses on writers and scholars for technical writing and multilingual... Read more
LibreOffice 4.3.0.4 - Free Open Source o...
LibreOffice is an office suite (word processor, spreadsheet, presentations, drawing tool) compatible with other major office suites. The Document Foundation is coordinating development and... Read more
Freeway Pro 7.0 - Drag-and-drop Web desi...
Freeway Pro lets you build websites with speed and precision... without writing a line of code! With it's user-oriented drag-and-drop interface, Freeway Pro helps you piece together the website of... Read more
Drive Genius 3.2.4 - Powerful system uti...
Drive Genius is an OS X utility designed to provide unsurpassed storage management. Featuring an easy-to-use interface, Drive Genius is packed with powerful tools such as a drive optimizer, a... Read more

Latest Forum Discussions

See All

Dawn of the Immortals Review
Dawn of the Immortals Review By Jennifer Allen on July 31st, 2014 Our Rating: :: RESPECTABLE EXPLORATIONUniversal App - Designed for iPhone and iPad Dawn of the Immortals might not re-invent the wheel, but it does tweak it a little... | Read more »
80 Days Review
80 Days Review By Jennifer Allen on July 31st, 2014 Our Rating: :: EPIC ADVENTUREUniversal App - Designed for iPhone and iPad A fantastic and fascinating re-envisioning of the classic novel by Jules Verne, 80 Days is a delightful... | Read more »
Battleheart Legacy Guide
The world of Battleheart Legacy is fun and deep; full of wizards, warriors, and witches. Here are some tips and tactics to help you get the most enjoyment out of this great game. | Read more »
Puzzle Roo Review
Puzzle Roo Review By Jennifer Allen on July 31st, 2014 Our Rating: :: PUZZLE-BASED TWISTUniversal App - Designed for iPhone and iPad A different take on the usual block dropping puzzle game, Puzzle Roo is quite pleasant.   | Read more »
Super Crossfire Re-Release Super Crossfi...
Super Crossfire Re-Release Super Crossfighter Coming Soon, Other Radiangames Titles Go 50% Off Posted by Ellis Spice on July 31st, 2014 [ | Read more »
Hexiled Review
Hexiled Review By Rob Thomas on July 31st, 2014 Our Rating: :: HEX SELLSUniversal App - Designed for iPhone and iPad In space, no one can hear you… spell? Hexiled is a neat concept for a word scramble puzzle, but it doesn’t go too... | Read more »
Summoners War: Sky Arena Passes 10 Milli...
Summoners War: Sky Arena Passes 10 Million Installs! Posted by Jessica Fisher on July 31st, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Deep Loot Review
Deep Loot Review By Jennifer Allen on July 31st, 2014 Our Rating: :: DIVE DEEPUniversal App - Designed for iPhone and iPad Dive deep in this fun explore-em-up that’s a little grind heavy but ultimately quite entertaining.   | Read more »
Despicable Me: Minion Rush is One Year O...
Despicable Me: Minion Rush is One Year Old, Gets its Biggest Update Yet Posted by Jennifer Allen on July 31st, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Fish & Shark Review
Fish & Shark Review By Jordan Minor on July 31st, 2014 Our Rating: :: FLAPPY FISHUniversal App - Designed for iPhone and iPad Fish & Shark’s beauty is only scale deep.   | Read more »

Price Scanner via MacPrices.net

Save up to $130 on an iPad mini with Apple re...
The Apple Store has Certified Refurbished 2nd generation iPad minis with Retina Displays available for up to $130 off the cost of new models, starting at $339. Apple’s one-year warranty is included... Read more
iPad Cannibalization Threat “Overblown”
Seeking Alpha’s Kevin Greenhalgh observes that while many commentators think Apple’s forthcoming 5.5-inch panel iPhone 6 will cannibalize iPad sales, in his estimation, these concerns are being... Read more
Primate Labs Releases July 2014 MacBook Pro P...
Primate Labs’ John Poole has posted Geekbench 3 results for most of the new MacBook Pro models that Apple released on Tuesday. Poole observes that overall performance improvements for the new MacBook... Read more
Apple Re-Releases Bugfixed MacBook Air EFI Fi...
Apple has posted a bugfixed version EFI Firmware Update 2.9 a for MacBook Air (Mid 2011) models. The update addresses an issue where systems may take longer to wake from sleep than expected, and... Read more
Save $50 on the 2.5GHz Mac mini, plus free sh...
B&H Photo has the 2.5GHz Mac mini on sale for $549.99 including free shipping. That’s $50 off MSRP, and B&H will also include a free copy of Parallels Desktop software. NY sales tax only. Read more
Save up to $140 on an iPad Air with Apple ref...
Apple is offering Certified Refurbished iPad Airs for up to $140 off MSRP. Apple’s one-year warranty is included with each model, and shipping is free. Stock tends to come and go with some of these... Read more
$250 price drop on leftover 15-inch Retina Ma...
B&H Photo has dropped prices on 2013 15″ Retina MacBook Pros by $250 off original MSRP. Shipping is free, and B&H charges NY sales tax only: - 15″ 2.3GHz Retina MacBook Pro: $2249, $250 off... Read more
More iPad Upgrade Musings – The ‘Book Mystiqu...
Much discussed recently, what with Apple reporting iPad sales shrinkage over two consecutive quarters, is that it had apparently been widely assumed that tablet users would follow a two-year hardware... Read more
13-inch 2.5GHz MacBook Pro on sale for $999,...
Best Buy has the 13″ 2.5GHz MacBook Pro available for $999.99 on their online store. Choose free shipping or free instant local store pickup (if available). Their price is $100 off MSRP. Price is... Read more
Save up to $300 on an iMac with Apple refurbi...
The Apple Store has Apple Certified Refurbished iMacs available for up to $300 off the cost of new models. Apple’s one-year warranty is standard, and shipping is free. These are the best prices on... 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
Sr. Product Leader, *Apple* Store Apps - Ap...
**Job Summary** Imagine what you could do here. At Apple , great ideas have a way of becoming great products, services, and customer experiences very quickly. Bring Read more
Sr Software Lead Engineer, *Apple* Online S...
Sr Software Lead Engineer, Apple Online Store Publishing Systems Keywords: Company: Apple Job Code: E3PCAK8MgYYkw Location (City or ZIP): Santa Clara Status: Full Read more
Sr Software Lead Engineer, *Apple* Online S...
Sr Software Lead Engineer, Apple Online Store Publishing Systems Keywords: Company: Apple Job Code: E3PCAK8MgYYkw Location (City or ZIP): Santa Clara Status: Full Read more
*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.