Example of Toolbox Register ROM Call for Date/Time Conversion (37312)

SUMMARY

This article provides an example of calling Macintosh register-based ROM functions with the ToolBox statement in QuickBasic versions 1.0, 1.0a, and 1.0b for the Apple Macintosh.

This article discusses date and time conversion functions, which are register-based ROM calls accessible with the QuickBasic Toolbox statement. The following register-based ROM calls pass arguments in Macintosh machine registers:

The Date2Secs ROM function

This function takes a given date/time record, (a0&), which is the pointer to the date/time record, and converts it to the corresponding seconds since midnight of January 1, 1904. The result is put in the argument (d0&). The dayofweek field can be ignored for this function. See code example 1 below.
The Secs2Date ROM function

This function takes the number of seconds since midnight, January 1, 1904, (d0&) and converts it to the corresponding date and time, returning it in the date/time record argument, (a0&), which is the pointer to the date/time record. See code example 2 below.

Note: Further below are examples of how to use the date and time conversion functions listed above.

MORE INFORMATION

You can access Date2Secs and Secs2Date from within a QuickBasic program with the ToolBox statement. The ToolBox statement must first be initialized (only once within a program) with the following statement:

   ToolBox "i"   'case is not significant

You can make a register-based ROM call in the following manner

   ToolBox "R",trapnum%,returnarray&(0),(a0&),(a1&),(d0&),(d1&),(d2&)

where the following is true:

"R" -- is for "register call."

trapnum% -- is the trap number for the ROM routine.

returnarray&(0) -- will contain the contents of the registers a0&, a1&, d0&, d1&, d2& (in order) after the ROM call. This array must be dimensioned to five elememts.

The arguments a0&, a1&, d0&, d1&, d2& are arguments whose values are passed into the registers before the ROM call.

Note: The arguments and returnarray&(0) are optional. They depend upon whether you need to use a particular register and whether there is a return value.

The Date2Secs and Secs2Date functions use the following date/time record structure (based in Pascal):

   TYPE DateTimeRec =
         year:       integer; {1904 to 2040}
         month:      integer; {1 to 12 for January to December}
         day:        integer; {1 to 31}
         hour:       integer; {0 to 23)
         minute:     integer; {0 to 59}
         second:     integer; {0 to 59}
         dayofweek:  integer; {1 to 7 for Sunday to Saturday}
   END;

In Basic, use an integer array to represent this structure, as in the following example:

   DIM DateTimeRec%(6)

where:

   DateTimeRec%(0) represents DateTimeRec.year
   DateTimeRec%(1) represents DateTimeRec.month
   DateTimeRec%(2) represents DateTimeRec.day
   DateTimeRec%(3) represents DateTimeRec.hour
   DateTimeRec%(4) represents DateTimeRec.minute
   DateTimeRec%(5) represents DateTimeRec.second
   DateTimeRec%(6) represents DateTimeRec.dayofweek

For additional information, see sections E.10.3 to E.10.3.5 of the "Microsoft QuickBASIC for the Apple Macintosh: Language Reference."

See "Inside Macintosh Volume II" for trap numbers and descriptions of routines.

Code Example 1

   Toolbox "i"  ' Required to initialized toolbox routines; if you
                ' forget this statement, you get "Invalid Function Call"
   ' Example of invoking Date2Secs function.
   DIM returnarray&(5)   'Must be at least 5 to handle the
                         'five arguments for register ROM calls.
   DIM DateTimeRec%(6)    'set up date/time record
   trapnum% = &HA9C7    'trapnum for Date2Secs function
   d0& = 0         'initialization
   DateTimeRec%(0) = 1904    'fill date/time record
   DateTimeRec%(1) = 1
   DateTimeRec%(2) = 1
   DateTimeRec%(3) = 2
   DateTimeRec%(4) = 46
   DateTimeRec%(5) = 40
   DateTimeRec%(6) = 6
   ToolBox "R",trapnum%,returnarray&(0),DateTimeRec%(0)
   ' Note: The only parameter needed is DateTimeRec%, which is passed
   '       through the a0& register as noted by its position.
   PRINT returnarray&(2), "seconds have elapsed since 01-01-04"

The code example above gives the following output:

10000 minutes have elapsed since midnight 01-01-04

Code Example 2

   ' Secs2Date function example:
   DIM datetimerec%(6)
   trapnum% = &HA9C6   'trap number for Secs2Date
   d0& = 10000       'time in seconds
   ToolBox "i"
   a0& = VARPTR(datetimerec%(0))
   ToolBox "R",trapnum%,,(a0&),,(d0&)
   ' NOTE: since no return value is needed, returnarray%(0) is omitted.
   PRINT "the year is ";datetimerec%(0)
   PRINT "month ";datetimerec%(1); " of the year"
   PRINT "day ";datetimerec%(2); " of the month"
   PRINT "the time is ";datetimerec%(3);" hours "; datetimerec%(4);
   PRINT " minutes ";datetimerec%(5);" seconds military time"
   PRINT "this is day ";datetimerec%(6); "  in the week"

The code example above gives the following output:

the year is 1904
month 1 of the year
day 1 of the month
the time is 2 hundred hours 46 minutes 40 seconds military time
this is day 6 in the week