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

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Macs Fan Control 1.3.1.0 - Monitor and c...
Macs Fan Control allows you to monitor and control almost any aspect of your computer's fans, with support for controlling fan speed, temperature sensors pane, menu-bar icon, and autostart with... Read more
NetShade 6.3.1 - Browse privately using...
NetShade is an anonymous proxy and VPN app+service for Mac. Unblock your Internet through NetShade's high-speed proxy and VPN servers spanning seven countries. NetShade masks your IP address as you... Read more
Dragon Dictate 4.0.7 - Premium voice-rec...
With Dragon Dictate speech recognition software, you can use your voice to create and edit text or interact with your favorite Mac applications. Far more than just speech-to-text, Dragon Dictate lets... Read more
Persecond 1.0.2 - Timelapse video made e...
Persecond is the easy, fun way to create a beautiful timelapse video. Import an image sequence from any camera, trim the length of your video, adjust the speed and playback direction, and you’re done... Read more
GIMP 2.8.14p2 - Powerful, free image edi...
GIMP is a multi-platform photo manipulation tool. GIMP is an acronym for GNU Image Manipulation Program. The GIMP is suitable for a variety of image manipulation tasks, including photo retouching,... Read more
Sandvox 2.10.2 - Easily build eye-catchi...
Sandvox is for Mac users who want to create a professional looking website quickly and easily. With Sandvox, you don't need to be a Web genius to build a stylish, feature-rich, standards-compliant... Read more
LibreOffice 5.0.1.2 - Free, open-source...
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
f.lux 36.1 - Adjusts the color of your d...
f.lux makes the color of your computer's display adapt to the time of day, warm at night and like sunlight during the day. Ever notice how people texting at night have that eerie blue glow? Or wake... Read more
VirtualBox 5.0.2 - x86 virtualization so...
VirtualBox is a family of powerful x86 virtualization products for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers... Read more
File Juicer 4.43 - Extract images, video...
File Juicer is a drag-and-drop can opener and data archaeologist. Its specialty is to find and extract images, video, audio, or text from files which are hard to open in other ways. In computer... Read more

ReBoard: Revolutionary Keyboard (Utilit...
ReBoard: Revolutionary Keyboard 1.0 Device: iOS Universal Category: Utilities Price: $1.99, Version: 1.0 (iTunes) Description: Do everything within the keyboard without switching apps! If you are in WhatsApp, how do you schedule a... | Read more »
Tiny Empire (Games)
Tiny Empire 1.1.3 Device: iOS Universal Category: Games Price: $2.99, Version: 1.1.3 (iTunes) Description: Launch cannonballs and blow tiny orcs into thousands of pieces in this intuitive fantasy-themed puzzle shooter! Embark on an... | Read more »
Astropad Mini (Productivity)
Astropad Mini 1.0 Device: iOS iPhone Category: Productivity Price: $4.99, Version: 1.0 (iTunes) Description: *** 50% off introductory price! ​*** Get the high-end experience of a Wacom tablet at a fraction of the price with Astropad... | Read more »
Emo Chorus (Music)
Emo Chorus 1.0.0 Device: iOS Universal Category: Music Price: $1.99, Version: 1.0.0 (iTunes) Description: Realistic Choir simulator ranging from simple Chorus emulation to full ensemble Choir with 128 members. ### introductory offer... | Read more »
Forest Spirit (Games)
Forest Spirit 1.0.5 Device: iOS Universal Category: Games Price: $2.99, Version: 1.0.5 (iTunes) Description: | Read more »
Ski Safari 2 (Games)
Ski Safari 2 1.0 Device: iOS Universal Category: Games Price: $1.99, Version: 1.0 (iTunes) Description: The world's most fantastical, fun, family-friendly skiing game is back and better than ever! Play as Sven's sister Evana, share... | Read more »
Lara Croft GO (Games)
Lara Croft GO 1.0.47768 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.47768 (iTunes) Description: Lara Croft GO is a turn based puzzle-adventure set in a long-forgotten world. Explore the ruins of an ancient... | Read more »
Whispering Willows (Games)
Whispering Willows 1.23 Device: iOS Universal Category: Games Price: $4.99, Version: 1.23 (iTunes) Description: **LAUNCH SALE 50% OFF** - Whispering Willows is on sale for 50% off ($4.99) until September 9th. | Read more »
Calvino Noir (Games)
Calvino Noir 1.1 Device: iOS iPhone Category: Games Price: $3.99, Version: 1.1 (iTunes) Description: The film noir stealth game. Calvino Noir is the exploratory, sneaking adventure through the 1930s European criminal underworld.... | Read more »
Angel Sword (Games)
Angel Sword 1.0 Device: iOS Universal Category: Games Price: $6.99, Version: 1.0 (iTunes) Description: Prepare to adventure in the most epic full scale multiplayer 3D RPG for mobile! Experience amazing detailed graphics in full HD.... | Read more »

Price Scanner via MacPrices.net

iPad Air 2 on sale for up to $100 off MSRP
Best Buy has iPad Air 2s on sale for up to $100 off MSRP on their online store for a limited time. Choose free shipping or free local store pickup (if available). Sale prices available for online... Read more
MacBook Airs on sale for $100 off MSRP
Best Buy has MacBook Airs on sale for $100 off MSRP on their online store. Choose free shipping or free local store pickup (if available). Sale prices for online orders only, in-store prices may vary... Read more
Big Grips Lift Handle For iPad Air and iPad A...
KEM Ventures, Inc. which pioneered the extra-large, super-protective iPad case market with the introduction of Big Grips Frame and Stand in 2011, is launching Big Grips Lift featuring a new super-... Read more
Samsung Launches Galaxy Tab S2, Its Most Powe...
Samsung Electronics America, Inc. has announced the U.S. release of the Galaxy Tab S2, its thinnest, lightest, ultra-fast tablet. Blending form and function, elegant design and multitasking power,... Read more
Tablet Screen Sizes Expanding as iPad Pro App...
Larger screen sizes are gaining favor as the tablet transforms into a productivity device, with shipments growing 185 percent year-over-year in 2015. According to a new Strategy Analytics’ Tablet... Read more
Today Only: Save US$50 on Adobe Elements 13;...
Keep the memories. lose the distractions. Summer’s winding down and it’s time to turn almost perfect shots into picture perfect memories with Elements 13. And get the power to edit both photos and... Read more
1.4GHz Mac mini on sale for $449, save $50
Best Buy has the 1.4GHz Mac mini on sale for $50 off MSRP on their online store. Choose free shipping or free local store pickup (if available). Price for online orders only, in-store price may vary... Read more
12-inch 1.1GHz Gold MacBook on sale for $1149...
B&H Photo has the 12″ 1.1GHz Gold Retina MacBook on sale for $1149.99 including free shipping plus NY sales tax only. Their price is $150 off MSRP, and it’s the lowest price available for this... Read more
27-inch 3.3GHz 5K iMac on sale for $1849, sav...
Best Buy has the 27″ 3.3GHz 5K iMac on sale for $1849.99. Their price is $150 off MSRP, and it’s the lowest price available for this model. Choose free shipping or free local store pickup (if... Read more
Worldwide Tablet Shipments Expected to Declin...
Does Apple badly need a touchscreen convertible/hybrid laptop MacBook? Yes, judging from a new market forecast from the International Data Corporation (IDC) Worldwide Quarterly Tablet Tracker, which... 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* Retail Online Store: Customer Insigh...
**Job Summary** Apple Retail (Online Store) is seeking an experienced e-commerce analytics professional to join the Customer Insights Team. The Web e-Commerce Analyst Read more
*Apple* Music, Business Operations - Apple I...
Changing the world is all in a day039s work at Apple . If you love innovation, here039s your chance to make a career of it. You039ll work hard. But the job comes with Read more
WW *Apple* Retail Online Store: Customer In...
**Job Summary** The Apple Retail - Online Store is seeking an experienced web merchandising analytics professional to join the Customer Insights Team. The Web Read more
Senior Payments Security Manager - *Apple*...
**Job Summary** Apple , Inc. is looking for a highly motivated, innovative and hands-on senior payments security manager to join the Apple Pay security team. You will Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.