1. Declarations & Definitions
struct employee
{
char n ;
int a ;
float s ;
} ;
struct employee e
Compulsory
= { ”Rahul”, 25, 4000.50 } ;
OR
[20]
Optional
struct employee
{
char n[20] ; int a ; float s ;
} e = { ”R ahul”, 25, 4000.50 } , x, y
;

2. Copying
main( )
{ struct emp
{
char n[20] ;
int a ;
float s ;
} ;
struct emp e1 = { ”Rahul”, 23, 4000.50 } ;
struct emp e2, e3 ;
e2.n = e1.n ;
strcpy strcpy ( ( ) ) ;;
e2.a = e1.a ;
e2.s = e1.s ;
e3 = e1 ;
printf ( ”%s %d %f”, e3.n, e3.a, e3.s ) ;
}
piecemeal
copying
copying at
one shot
e2.n, e1.n

3. Copying Arrays
int a[10] = { 3, 6, 5, … } ;
int b[10] ;
for ( i = 0 ; i <= 9 ; i++ )
b[i] = a[i] ;
struct z
{
int arr[10] ;
} ;
struct z b ;
struct z a
b = a ;
OR
= { 3, 6, 5, ... } ;

4. Nested Structures
main( )
{ struct address
{
char city[20] ;
long int pin;
} ;
struct emp
{
char n[20] ;
f - int
printf ( ”%d”, a.b.c.d.e.f ) ;
struct emp e = { ”Rahul”, 23, ”Nagpur”, 440010,
4000.50 } ;
printf ( ”%s %d%s%ld%f”, e.n,
}
e.age, e.pin,
e.s ) ;
e.city,
int age ;
struct address a ; float s ;
} ;
ee..aa..ppiinn
ee..aa..cciittyy aa..cciittyy

5. Passing Structure Elements
main( )
{
struct book
{
char n[20] ; int nop ; float pr ;
} ;
struct book b = { ”Basic”, 425, 135.00 } ;
display ( b.n, b.nop,b.pr ) ;
show } ( b.n, &b.nop, &b.pr ) ;
display ( char *n, int pg, float p )
{
} printf ( ”%s %d %f”, n, pg, p ) ;
show ( char *n, int *pg, float *p )
{
printf ( ”%s %d %f”, n, *pg, *p ) ;
}

6. ( * b b ) .n,
main( )
{
struct book
{
char n[20] ; int nop ; float pr ;
} ;
struct book b = { ”Basic”, 425, 135.00 } ;
display1 ( b ) ; show1 ( &b ) ;
} display1 ( )
{
} printf ( ”%s %d %f”,
show1 ( )
{ printf ( ”%s %d %f”,
}
Passing Structures
struct book bb
bb.n, bb.nop, bb.pr ) ;
struct book *bb
( * )
bb .nop,
( * )
bb .pr ) ;
printf ( ”%s %d %f”, bb -> n , bb -> nop,
bb -> pr ) ;

7. main( )
{
struct com
{
float r, i ;
} ;
struct com a
struct com b = { 1.2, 1.7 } ;
struct com add ( struct com, struct com ) ;
c = add ( a, b ) ;
printf ( ”%f %f”, c.r, c.i ) ;
}
add ( struct com x, struct com y )
}
Complex Nos.
struct com c ;
struct com z ;
x.r + y.r ;
x.i + y.i ;
= { 2.5, 1.3 } ;
struct com add ( struct com x, struct com y )
{
z.= x.+ y.r ;
z.= x.+ y.i ;
return z ;

8. Applications of Structures
Database Management
Positioning Cursors
Receiving ascii and scan codes
Displaying characters
Printing on printer
Mouse Programming
Graphics Programming
All Disk Operations
etc.

9. Floppy Disks
JJaacckkeett
WWrriittee PPrrootteecctt nnoottcchh
PPllaatttteerr (( mmyyllaarr ))
HHuubb rriinngg
RReeaadd // WWrriittee sslloott
RReettrraaccttaabbllee mmeettaall sshheeaatthh
Access to magnetic surface
Access to magnetic surface
Platter ( only when retracted )
( mylar )
( only when retracted )
WWrriittee PPrrootteecctt nnoottcchh
Platter
( mylar )

10. Hard Disk
SSppiinnddllee
RReeaadd // WWrriittee HHeeaadd
HHeeaadd AAsssseemmbbllyy
PPllaatttteerr (( aalluummiinniiuumm ))

11. SSeeccttoorrss
Parts of Platter
ooff ssaammee ccaappaacciittyy
TTrraacckkss

12. Specs Of Floppy Disks
Type
360 KB
1.2 MB
1.44 MB
Sides
222
Trk/side
40
80
80
Sec/Trk
9
15
18
Dia.
5 1/4 ”
5 1/4 ”
3 1/2 ”
TPI
48
96
135
Name
DSDD-D9
HD-QD15
2HD-QD18
BByytteess // SSeeccttoorr ffoorr aannyy ddiisskk == 551122
CCaappaacciittyy ooff DD99 ddiisskk ==
22 ** 4400 ** 99 ** 551122 // 11002244
336600 KKBB

13. Logical Organization
17
18
1
2
11
10
Boot
Sector
Boot
Sector
3
6 5 4
D
F2
SSiiddee 00,, TTrraacckk 00 SSiiddee 11,, TTrraacckk 00
F1
7
11
F1
8
10
9
12
13 14 15
16
17
18
1
3
2
6 5 4
7
8
9
12
13 14 15
16
D
D
D D D
D
D
D
D
D
D D D
F1
F1
F1 F1 F1
F1
F1
F2
F2 F2 F2
F2
F2
F2
F2

14. main( )
{
Reading Boot Sector
char arr [ 512 ] ; int i ;
printf ( ”Enter floppy in drive A,
press any key …” ) ;
getch( ) ;
absread ( ) ;
0, 1, 0, arr
for ( i = 0 ; i 512 ; i++ )
printf ( ”%c”, arr [ i ] ) ;
Boot Sector 11
SSiiddee 00,, TTrraacckk 00
#include ”dos.h”
}

15. CChhaapptteerr 1100
CChhaapptteerr 1100