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1991-02-11
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Determining
&
Controlling
Hardware
"Never let a domestic quarrel ruin a day's writing. If you can't start
the next day fresh, get rid of your wife."
Mario Puzo
This chapter describes the objects included in the totSYS unit. There
are four objects in all, designed to provide information about the
hardware and operating system on which an application is running. Dis-
playOBJ is an object relating to the monitor/display card; EquipOBJ
returns information about the peripheral devices installed on the
computer; MemOBJ provides information about base, extended and expanded
memory; OSOBJ provides information about the operating system and the
DOS configurable international settings.
A full example illustrating the use of each object can be found at the
end of the chapter.
Using DisplayOBJ
The public methods (i.e. the methods you should be calling) in Display-
OBJ are designed to provide you with information about the computer
display. Since other units in the Toolkit also need to know this
information, a global instance, called Monitor, is automatically ini-
tialized when the totSYS unit is used. Monitor is, in fact, a pointer
to an object on the heap, and has to be referenced with the pointer
symbol, e.g. Monitor^. There should be no reason to initialize another
DisplayOBJ, just access the Monitor^ methods. The following methods are
available:
SnowProne: boolean
This function method returns true if the display is a "snowy" CGA.
Since the screen writing routines in totFAST take care of snow, you
should not normally need to call this method.
GetMode:byte
Returns the current display mode, e.g. mode 3 is 80 column color mode.
Refer to the Turbo Pascal Programmer's Guide or a DOS Technical Refer-
ence for more information about display modes.
ColorOn:boolean
4-2 User's Guide
--------------------------------------------------------------------------------
This function returns true if the system is capable of color display.
This function is normally called to determine whether to use monochrome
or color display attributes when overriding the Toolkit's defaults.
This function will always return false if ForceBW is set to true (dis-
cussed next). It also returns false if the user is using a color sys-
tem, but has set the device to BW80 mode.
SetBW(On:boolean)
Call this procedure and pass a true value if you want to force the
system to use monochrome values. This is useful for laptop systems
where the system responds as a color device, but the user only sees
gray (or orange!) scales. Because LookTOT was initialized before your
program code was executed, you should also call LookTOT^.SetDefaults,
and LookTOT will then be assigned the default monochrome settings.
DisplayType: tVideo
The totSYS unit defines an enumerated type tVideo which has the follow-
ing members: UnKnown, Mono, CGA, MCGAmono, MCGAcol, EGAmono, EGAcol,
VGAmono and VGAcol. The function display type checks the installed
hardware and returns the appropriate member.
BaseOfScreen: pointer;
This function returns a pointer to the base address of video memory.
This is $B800:0000 for color systems and $B000:0000 for monochrome.
Unless you are using non-Toolkit routines to directly access video
memory, you should not need to call this method.
Width: byte
This function returns the width of the display in characters, which is
commonly a value of 80.
Depth: byte
This function returns the depth of the display in lines. In normal
display mode the function will return 25, but in condensed mode an EGA
system will return 43, and a VGA system will return 50.
The following two methods are used to switch an EGA or VGA display
system between condensed and normal modes.
SetCondensed: byte;
Hardware 4-3
--------------------------------------------------------------------------------
This function tries to set the display to condensed mode, and returns
the number of text lines the system can display in condensed mode. Note
that only EGA and VGA systems can be set into condensed mode.
4-4 User's Guide
--------------------------------------------------------------------------------
Set25;
This procedure forces the display into 25 line mode.
Using EquipOBJ
The EquipOBJ object is designed to provide information about the
installed hardware devices. Most of the EquipOBJ methods reflect the
data which the user defined with the SETUP operating system command.
This may not correspond with the actual physical configuration, but is
the only configuration which DOS will allow software to access. Equi-
pOBJ includes the following methods:
ComputerID:byte;
This function returns a byte indicating the basic system type. The
computer ID was implemented by IBM to provide an easy way for differen-
tiating between the various IBM personal computers. The following list
shows the hexadecimal values of the IBM range:
$FF - IBM PC
$FE,$FB - IBM XT or portable
$FD - the infamous PC Junior
$FC - IBM AT, XT-286, PS/2 50 and 60
$FA - PS/2 25 and 30
$F9 - IBM PC Convertible
$F8 - PS/2 80
Some non-IBM systems do not follow this convention, and an unlisted
number may be returned by this method.
ParallelPorts: byte;
This function returns the number of installed parallel ports (LPTx).
SerialPorts: byte;
This function returns the number of installed serial ports (COMx).
FloppyDrives: byte;
This function returns the number of physical diskette drives.
ROMDate: string;
Hardware 4-5
--------------------------------------------------------------------------------
Returns an eight character string representing the ROM date in the
format MM/DD/YY.
GameAdapter: boolean;
Returns true if a game adapter is installed.
Serialprinter: boolean;
Returns true if a serial printer is configured.
MathChip: boolean;
Returns true if a math co-processor is detected. If you compile Toolkit
programs with the compiler directive FLOAT enabled, but FLOATEM dis-
abled, the program will only run on systems equipped with a math co-
processor. Use this function during program initialization to ensure
the host PC is adequately equipped.
Using MemOBJ
The MemOBJ methods provide data related to base, extended and expanded
memory on the host PC. The following function methods are provided:
BaseMemory: integer;
Returns the total amount of base memory installed, i.e. memory up to
640k. The value is returned in kilobytes ("k"). Remember that the Turbo
Pascal functions MemAvail and MaxAvail provide data on free memory,
i.e. memory not being used by device drivers and programs.
EMMInstalled: boolean;
Returns true if an expanded memory manager is installed.
EMMversionMajor: byte;
Returns the expanded memory manager major version number, i.e. the
whole portion of the version number. If an EMM is not installed, a 0 is
returned.
EMMversionMinor: byte;
Returns the expanded memory manager minor version number, i.e. the dec-
imal portion of the version number. If an EMM is not installed, or if
the minor version number is zero, a 0 is returned.
4-6 User's Guide
--------------------------------------------------------------------------------
EMMversion: string;
Returns a three character string representing the complete EMM version
number, e.g. "4.0".
MaxExpMem: word;
Returns the total amount of installed expanded memory in kilobytes.
ExpMemAvail: word;
Returns the amount of unused (or available) expanded memory in kilo-
bytes.
ExtMemAvail: word;
Returns the amount of unused extended memory in kilobytes.
Using OSOBJ
The OSOBJ object is designed to provide information about the operating
system. This unit is particularly useful when programs need to be
developed for the international (read: non-American!) market place,
because the DOS configuration can be ascertained, including the date
format, currency symbol, country code, etc.
If you develop a program to be distributed internationally, you need to
adhere to the host countries' formatting conventions, especially date
and number formats. Refer to chapter 11: Controlling User Input for a
full discussion of this topic.
The following function methods are available:
OSVersionMajor: byte;
Returns the major DOS version number, e.g. 2, 3 or 4.
OSVersionMinor: byte;
Returns the minor DOS version number, e.g. 1.
OSVersion: string;
Returns the full DOS version number as a string, e.g. "3.1"
Country: word;
Hardware 4-7
--------------------------------------------------------------------------------
Returns a word which represents the country code. In general, the coun-
try codes are the same as the 3-digit international phone access code.
Some of the more common codes are:
001 United States
002 Canada (French)
003 Latin America
031 Netherlands
032 Belgium
033 France
034 Spain
039 Italy
041 Switzerland
044 United Kingdom
045 Denmark
046 Sweden
047 Norway
049 Germany
061 Australia
351 Portugal
358 Finland
Currency: string;
Returns a string identifying the country's currency abbreviation. On
systems using DOS prior to version 3.0, only a signal character can be
accessed. However, systems using DOS 3.0 and later may return more than
one character, e.g. FFR, DKR.
DateFmt: tDate;
The totSYS unit includes the declaration of the tDATE enumerated type
which has three members: USA, EUROPE and JAPAN. This function returns
the member which represents the operating system default date format.
Note that the three formats are MM-DD-YY, DD-MM-YY and YY-MM-DD,
respectively.
ThousandsSep: char;
Returns the character used to punctuate the thousands mark in numbers.
The USA uses a comma, whereas many other countries use a period or a
space.
DecimalSep: char;
Returns the character used to punctuate the decimal place. This is
usually a period or a comma.
4-8 User's Guide
--------------------------------------------------------------------------------
DateSep: char;
Returns the character used to separate the month, day and year elements
of a date, e.g. "/", "-". Note: this information is not accessible on
systems using DOS prior to version 3.0. If the machine does not have
DOS 3.0 or later, a '/' is returned.
TimeSep: char;
Returns the character used to separate the hours, minutes and seconds
when displaying the time, e.g. ":". Note: this information is not
accessible on systems using DOS prior to version 3.0. If the machine
does not have DOS 3.0 or later, a ':' is returned.
TimeFmt: byte;
Returns a byte to indicate the preferred time display. A 0 indicates a
12 hour format, and a 1 indicates a 24 hour format. Note: this informa-
tion is not accessible on systems using DOS prior to version 3.0. If
the machine does not have DOS 3.0 or later, a 0 is returned.
CurrencyFmt: byte;
Returns a byte indicating the currency format. One of the following
five values will be returned:
0 String leads currency, no space
1 String follows currency, no space
2 String leads currency, one space
3 String follows currency, one space
4 String replaces decimal separator
Note: this information is not accessible on systems using DOS prior to
version 3.0. If the machine does not have DOS 3.0 or later, a 0 is
returned.
CurrencyDecPlaces: byte;
Returns the number of decimal places normally used with the country's
currency. Note: this information is not accessible on systems using DOS
prior to version 3.0. If the machine does not have DOS 3.0 or later, a
2 is returned.
Hardware 4-9
--------------------------------------------------------------------------------
Example
Listed below is the demo program, DEMSY1, which illustrates the use of
each of the four totSYS objects. Figure 4.1 reflects the resultant
output on a VGA computer.
Program DemoSystemOne;
{DEMSY1}
USES DOS,CRT, TOTSYS;
var
Equip: EquipObj;
Mem: MemObj;
OS: OSObj;
Lines: byte;
begin
ClrScr;
Lines := Monitor^.SetCondensed;
if Monitor^.ColorOn then
writeln('This system is color')
else
writeln('This system is monochrome');
with Equip do
begin
Init;
Writeln('Machine ID: ',ComputerID);
Writeln('Parallel Ports: ',ParallelPorts);
Writeln('Serial Ports: ',SerialPorts);
Writeln('Floppy Drives: ',Floppydrives);
Writeln('ROM date: ',RomDate);
Writeln('Game Adapter: ',GameAdapter);
Writeln('Serial printer: ',Serialprinter);
Writeln('Math Coprocessor: ',MathChip);
Writeln;
end;
with Mem do
begin
Init;
Writeln('Base memory: ',Basememory,'k');
Writeln('Avail Extended memory: ',ExtMemAvail,'k');
if EMMInstalled then
begin
Writeln('Total Expanded memory: ',MaxExpMem,'k');
Writeln('Avail Expanded memory: ',ExpMemAvail,'k');
Writeln('Expanded memory manager version: '+
EMMversion);
end
else
4-10 User's Guide
--------------------------------------------------------------------------------
Writeln('Expanded memory not installed: ');
writeln;
end;
with OS do
begin
Init;
Writeln('Operating System Version: '+OSversion);
Writeln('Country Code: ',Country);
write('Currency String: ',Currency,' ');
case CurrencyFmt of
0: writeln('(String leads currency, no space)');
1: writeln('(String follows currency, no space)');
2: writeln('(String leads currency, one space)');
3: writeln('(String follows currency, one space)');
4: writeln('(String replaces decimal separator)');
end; {case}
writeln('Currency Decimal Places: ',CurrencyDecPlaces);
write('Thousands Separator: ','''',ThousandsSep,'''');
writeln(' Decimal Separator: ','''',DecimalSep,'''');
case DateFmt of
USA: writeln('Date Format: MM DD YY');
Europe: writeln('Date Format: DD MM YY');
Japan: writeln('Date Format: YY MM DD');
end; {case}
write('Date separator: ','''',DateSep,'''');
writeln(' Time separator: ','''',TimeSep,'''');
if TimeFmt = 0 then
writeln('Time is displayed on a 12 hour clock')
else
writeln('Time is displayed on a 24 hour clock');
end;
write(' press any key ...');
Repeat until keypressed;
if Lines > 25 then
Monitor^.Set25;
end.
Notice that the INIT method is not called for the Monitor^ instance.
This is because Monitor^ is a global instance, and the Toolkit automat-
ically initializes all global instances.
Figure 4.1 [SCREEN]
The System Demo
Program