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IBM System./3 Model 15
Communications Control Program System Reference Manual
Program Numbers:
5704-SC1 5704-SCz
Featu res 60 1 1 160121 60331007 0 /GO7 1
GC21-7620-6 File No. 33-36
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Seventh Edition (September 19801
T h i s i s a m a j o r r e v i s i o n o f , and obsoletes,GC2l-7620-5. Changes o r a d d i t i o n s t o t h e t e x t a n d i l l u s t r a t i o n s a r e i n d i c a t e d b y a v e r t i c a l l i n e t o t h e l e f t o f t h e c h a n g e o r a d d i t i o n .
T h i s e d i t i o n a p p l i e s to t h e f o l l o w i n g I B M S y s t e m / 3 s y s t e m c o n t r o l p r o g r a m s a n d t o a l l s u b s e q u e n t v e r s i o n s a n d m o d i f i c a t i o n s u n t i l o t h e r w i s e in d i c a t e d in n e w e d i t i o n s o r t e c h n i c a l n e u r s l e t t e r s .
Version Modification Program Number System/3 Model
08 00
05 00
5 7 0 4 - 5 C 1 5704-SC2
M o d e l 1 5 A - B - C Model 1 5D
C h a n g e s a r e p e r i o d i c a l l y m a d e t o t h e i n f o r m a t i o n h e r e i n ; c h a n g e s w i l l b e r e p o r t e d i n t e c h n i c a l n e w s l e t t e r s o r i n n e w e d i t i o n s o f t h i s o u b l i c a t i o n .
Use this publication only for the purposes stated in the Preface.
P u b l i c a t i o n s a r e n o t s t o c k e d a t t h e a d d r e s s b e l o w . R e q u e s t s f o r c o p i e s o f I B M p u b l i c a - t i o n s a n d f o r t e c h n i c a l in f o r m a t i o n a b o u t t h e s y s t e m s h o u l d b e m a d e t o Vour IBM r e p r e s e n t a t i v e o r t o t h e I B M b r a n c h o f f i c e s e r v i n g y o u r l o c a l i t y .
T h i s p u b l i c a t i o n c o u l d c o n t a i n t e c h n i c a l in a c c u r a c i e s o r t y p o g r a p h i c a l e r r o r s . A d d r e s s y o u r c o m m e n t s about this publication to IBM Corporation, Publications, Department 2 4 5 , R o c h e s t e r , M i n n e s o t a 5 5 9 0 1 . I B M m a y u s e a n d d i s t r i b u t e a n y o f t h e i n f o r m a t i o n y o u s u p p l y i n any way it believes a p p r o p r i a t e w i t h o u t i n c u r r i n g a n y o b l i g a t i o n w h a t e v e r . Y o u m a y , o f c o u r s e , c o n t i n u e t o u s e t h e i n f o r m a t i o n y o u s u p p l y .
O C o p y r i g h t I n t e r n a t i o n a l B u s i n e s s M a c h i n e s C o r p o r a t i o n 1 9 7 3 , 1 9 7 4 , 1 9 7 5 , 1 9 7 6 , 1 9 7 7 , 1 9 7 8 , 1 9 7 9 , 1 9 B O
Preface
This publication describes the Communications Control o tBM System/3 Modet l5 Operator,s Guide, GC21-5075.
P r o g r a m ( C C P ) f e a t u r e o f t h e I B M S y s t e m / 3 M o d e l lS a n d
provides information to aid the system installation manager, . IBM System/3 Model lE System Control programmrng IBM systems engineer, and application programmers in Reference Manual, GC21.SO77 (S704-SC1).
generating the CCP system.
o IBM System/3 Model lS System Control programming The generation of the CCP system is accomplished by using Concepts and Reference Manual, GC21-b162 (b704"SC2).
t h e f a c i l i t i e s o f t h e :
o IBM System/3 Model lS System Cantrol programming o f BM System/3 Model 15 system Control programming Macros Reference Manual, Gc21-7609.
( 5 7 0 4 - S C 1 a n d 5 7 0 4 - S C 2 )
. IBM System/3 Overlay Linkage Editor Reference a P r o g r a m m i n g s u p p o r t f o r t h e c o m m u n i c a t i o n a d a p t e r s : M a n u a l , G C 2 1 - 7 5 6 1 .
M u l t i l i n e / M u l t i p o i n t f e a t u r e M u l t i p l e L i n e T e r m i n a l
Adapter feature (PSHRPO number 5799-WFK) . IBM System/3 Model l5 Scheduler Logic Manual,
s Y 2 1 _ 0 0 3 5 .
Prerequisite Knowledge t IBM System/3 Model 15 Supervisor and IOS Logic
Manual. SY21-0033.
Y o u s h o u l d b e a n e x p e r i e n c e c l S y s t e m / 3 M o d e l 1 b u s e r
familiar with the basic concepts of teleprocessing. . IBM System/3 Model l5 Data Management Logic Manual, SY21-0034.
Devices and Programs Supported and Required . l9M Systeml3 Model 15 System Data Areas and Diag- nostic Aids. SY21 -0032 (5704-SCl ).
T h e te r m i n a l d e v i c e s , s y s t e m d e v i c e s , a n d s y s t e m p r o g r a m s
r e q u i r e d a n d s u p p o r t e d b y t h e C C P a r e l i s t e d i n A p p e n d i x .l B M S y s t e m / 3 M a d e t ls s y s t e m D a t a A r e a s a n d D i a g -
D. nostic Aids, Sy21_0052 (5704-SC2)"
y'y'oter This manual follows the convention thatre means . tBM System/3 Modet li Systent Services programs
he or she. Logic Manual, Sy21-0036.
Refated Publications . IBM System/3 Muttitine/Multipoint Einary Synchronous
Comm un icati on s R eference Man u al. GCZI _7 57 3.
. I8M System/3 Communications Control Program Mes-
sages Manual, GC21-5170. . l9M System/3 Multiple Line Terminal Adapter Rpe
Program Reference and Component Descriptiort Manual,
. l8M System/3 Model l5 Communication Control pro- GC21-7560.
gram System Operator Guide, GC21-7619.
. IBM 1050 Data Cornmunication System principles af . IBM System/3 Communication Control Program Terminal operation. GA24-3474.
O perato r's G u ide, GC21 -7 58O.
. IBM 2740 Communicatiotts Terminal Models I and 2
. IBM System/3 Communications Control Program Component Description, GA24-3403.
Programmer's Reference Manual, GC21 -7 579.
. IBM 2741 Communication Terminal. GA24-341S.
o IBM System/3 Communications Control program System
Design Guide, GC21-5165. ' IBM System/7 Systems Summary, GA34-0002.
P r e f a c e i i i
a
l .
II 8M SystemD B inary Synchronous Communications Module (RPQ) Pragramming Guide and Reference Manual, SC34-1510.
I BM System/7 Teleprocessing Multiplexor'"TPMM"
Programming Guide and Reference Manual Supporting RPO DMAt /, SC34-1506.
IBM 3270 lnformation Display System Component Description. GA2l 27 49.
l8M 3735 Programmer's Guide, GC3O-3001.
IBM System/3 3735 Support Program Coding Manual, G C 2 i - 5 0 9 6 .
IBM 3741 Data Station Reference Manual. G421-9183.
IBM System/3 Disk Sort Reference Manual, SC21-7522.
IBM System/3 Model | 5 User's Guide to Spooling, c c 2 1 7 6 3 2 .
IBM System/3 Sabsef American National Standard CO BO L Reference Manual, GC28-6452.
IBM System/3 RPG ll Reference Manual, SC21-7504.
l8M System/3 FORTRAN lV Reference Manual, s c 2 8 - 6 8 7 4 .
l8M System/3 Basic Asrembler Program Reference Manual. SC21-7509.
I BM Systen/34 lnteractive Communications Feature Reference Manual , SC21"7751.
Contents
C H A P T E R 1 . I N T R O D U C T I O N T e r m i n a l O p e r a t o r F a c i l it i e s S y s t e m O p e r a t o r F a c i l i t i e s . P r o g r a m m i n g F a c i l i t i e s . Devices and Programs Supported E s t a b l i s h i n g a n d O p e r a t i n g t h e C C P
G e n e r a t i o n S t a g e A s s i g n m e n t S t a g e O p e r a t i o n a l S t a g e C C P T a s k s
R e l a t i o n s h i p to O t h e r P r o g r a m s D i s k S y s t e m M a n a g e m e n t (D S M )
E x is t i n g C o m m u n ic a t i o n s P r o g r a m m i n g S u p p o r t A p p l i c a t i o n P r o g r a m s
System Programs
C H A P T E R 2 . U S I N G T H E C C P F R O M A T E R M I N A L How the Terminal Operator Requests a Program How the Terminal Operator Requests System Services . T e r m i n a l M o d e s
I n i t i a l M o d e C o m m a n d M o d e . D a t a M o d e
C o m m a n d I n t e r r u p t M o d e . T e r m i n a l O p e r a t o r C o m m a n d s
S i g n - O n C o m m a n d ( / O N )
O u e u e / N o - O u e u e C o m m a n d s ( / O a n d / N O O I C o m m a n d M e a n i n g
F i l e S p e c i f i c a t i o n C o m m a n d ( / F l L E l . N a m e C o m m a n d ( / N A M E ) .
P r o g r a m R e q u e s t C o m m a n d Data Mode Escape Command R e l e a s e C o m m a n d ( / R E L E A S E ) M e s s a g e C o m m a n d ( / M S G I . R u n C o m m a n d ( / R U N I . S i g n - O f { C o m m a n d ( / O F F ) P l a n n i n g C o n s i d e r a t i o n s
C H A P T E B 3 . S Y S T E M O P E R A T O R C O N T R O L O F T H E C C P
l n i t i a t i n g C C P
S y s t e m O p e r a t o r C o m m a n d s M e s s a g e C o m m a n d ( M S G ) D i s p l a y T e r m i n a l S t a t u s ( D T ) . D i s p l a y T e r m i n a l A s s i g n m e n t s ( D A) D i s p l a y U s e r s C o m m a n d ( D U ) C a n c e l a U s e r P r o g r a m o r t h e C C P
S u s p e n d R e q u e s t s / E x e c u t i o n / l n i t i a t i o n o f U s e r P r o g r a m s
R e s u m e R e q u e s t s / E x e c u t i o n / l n i t i a t i o n o f U s e r P r o g r a m s
C h a n g e t h e S t a t u s o f a T e r m i n a l ( V A R Y ) C l o s e / O o e n t h e B S C A L i n e ( C L O S E / O P E N I A s s i g n a S y m b o l i c T e r m i n a l N a m e t o a T e r m i n a l
{ A S S I G N )
O n l i n e T e r m i n a l T e s t ( T E S T )
C h a n g e t h e I n t e r v a l P o l l i n g T i m e f P O L T I M E ) R e c o v e r f r o m T e r m i n a l E r r o r s (E R P ) .
C o n t r o l A u t o m a t i c R e t r i e s o f T e r m i n a l s D u r i n g E r r o r R e c o v e r y ( A U T O E R P ) { P r o g r a m N u m b e r 5 7 0 4 - S C 2 O n l v )
S a v e T r a c e T a b l e I n f o r m a t i o n ( T R A C E I I n i t i a t e o r T e r m i n a t e t h e C C P T r a c e ( T R A C E )
( P r o g r a m Number 57O4-SC2 Onlv) U s i n g t h e S y s t e m O p e r a t o r ' s C o n s o l e a s a
R e q u e s t i n g T e r m i n a l
C l o s i n g a n d O p e n i n g D i s k F i l e s U n d e r C C P
C l o s i n g a n d O p e n i n g D i s k F i l e s F r o m a B a t c h P a r t i t i o n ( P r o g r a m Number 5704-SC2 Only)
S h u t t i n g D o w n C C P System Operator Messages
C C P R e s o o n s e s
M e s s a g e s f r o m T e r m i n a l O p e r a t o r s Messages f rom User Programs P l a n n i n g a n d t h e S y s t e m O p e r a t o r O p e r a t i n g A i d s
C H A P T E R 4 . C C P S E R V I C E S F O R T H E A P P L I C A T I O N P R O G R A M M E R
F a c i l i t i e s O f f e r e d b y t h e C C P C o m m u n i c a t i o n s M a n a g e m e n t F il e M a n a g e m e n t
P r o g r a m M a n a g e m e n t
C H A P T E R 5 . D E S I G N I N G Y O U R C O M M U N I C A T I O N S . BASED SYSTEM
A p p l i c a t i o n s T e r m i n a l s D a t a F il e s P r o g r a m s
E s t a b l i s h i n g th e S y s t e m O p e r a t i n g th e S y s t e m
S t a r t u p O p e r a t i o n S h u t d o w n U p d a t i n g t h e S y s t e m T o t a l E q u i p m e n t N e e d s
D i s k S y s t e m M a n a g e m e n t (D S M ) C o n s i d e r a t i o n s S p o o l i n g C o n s i d e r a t i o n s ( P r o g r a m Number 5704-SCl ) S p o o l i n g C o n s i d e r a t i o n s ( P r o g r a m Number 5704-SC2) C C P T r a c e
M u l t i p l e P a r t i t i o n C o n s i d e r a t i o n s S h a r i n g F i l e s B e t w e e n P a r t i t i o n s
3 2 7 O D i s p l a y F o r m a t F a c i l i t y ( D F F ) C o n s i d e r a t i o n s U s i n g th e S a m e T e r m i n a l w i t h D F F a n d
N o n - D F F P r o g r a m s T e r m i n a l S e c u r i t y C o n s i d e r a t i o n s C H A P T E R 6 . G E N E R A T I O N S T A G E P r o c e d u r e f o r G e n e r a t i o n
O p e r a t i o n a l P r o c e d u r e s f o r G e n e r a t i o n G e n e r a t i o n C o n t r o l S t a t e m e n t s
W r i t i n g G e n e r a t i o n C o n t r o l S t a t e m e n t s
$ E F A C - C C P F a c i l i t i e s
$ E P L G - P r o g r a m m i n g L a n g u a g e s
$ E S E C - T e r m i n a l S i g n O n S e c u r i t y
$ E F lL - $ C C P F I L E A l l o c a t i o n
$ E M L A - M L T A S u p p o r t
$ E M L D - M L T A D e v i c e s
$ E B S C - B S C S u p p o r t
$ E B S D - B S C D e v i c e s
$ E C S C - B S C C S u p p o r t ( 5 7 0 4 - S C 2 o n l y )
$ E C S D - B S C C D e v i c e s I
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$ E G E N - C C P G e n e r a t i o n S t r e a m 8 1 A d d i t i o n a l D e v i c e s S u p p o r t e d 1 7 2
C C P P r o g r a m s U s e d in G e n e r a t i o n 8 4 S y s t e m P r o g r a m s R e q u i r e d 1 1 2
G e n e r a t i o n U t i l i t v ( $ C C I P P ) 8 4
S C P G e n e r a t o r ( $ C G x x x ) 8 4 A P P E N D I X E . G L O S S A R Y 1 7 3
I n i t i a l i z e A s s i g n m e n t F i l e B u i l d ( $ C C l B F l U I n i t i a l i z e T r a c e / D u m p F i l e ( $ C C l D P )
l P r o q r a m N u m b e r 5 7 0 4 - S C 2 o n l y l 8 4 S T O R A G E E S T I M A T E S A N D P E R F O R M A N C E S o u r c e M o d u l e s U s e d in G e n e r a t i o n 8 5 C O N S I D E B A T I O N S
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| M a x i m u m C C P S y s t e m E x a m p l e ( 5 7 0 4 - S C 2 O n l y ) 2 O 4 D i s k S t o r a g e E s t i m a t e s f o r t h e C C P 2 1 9
. 224 A P P E N O I X F . C O N F I G U R A T I O N L I M I T A T I O N S ,
175 G e n e r a t i o n C o n s i d e r a t i o n s 8 5 C o n f ig u r a t i o n L i m i t a t i o n s a n d M a i n S t o r a g e E s t i m a t e s 1 7 5 S u p p o r t o f t h e D i s p l a y A d a p t e r 8 5 E s t i m a t i n g C C P C o n f ig u r a t i o n L i m i t s 1 7 5 S u p p o r t o f B S C C ( B i n a r y S y n c h r o n o u s
C o m m u n i c a t i o n s C o n t r o l l e r )
S u p p o r t o f a L a r g e N u m b e r o f T e r m i n a l s
( P r o g r a m Number 5704-SC2 only) 8 6 T i p s f o r l m p r o v e d P e r f o r m a n c e a n d M a i n S t o r a g e
U t i l i z a t i o n 2 2 3
C H A P T E R 7 . A S S I G N M E N T S T A G E 8 7 C C P U s e r T a s k P r i o r i t i e s
P l a n n i n g fo r A s s i g n m e n t 8 7
R e q u i r e m e n t s f o r A s s i g n m e n t a 7 A p p E N D l x c . t N s r A L L A T t o N v E R t F t c A T r o N
A s s i g n m e n t R e s t r i c t i o n s (5 7 0 4 - S C 2 o n l y ) 8 8 P R O G R A M Z 2 g
A s s i g n m e n t D i a g n o s t i c s 8 8 L o a d i n g t h e C C P t o R u n C C P I V P 2 2 9
8 8 P r o c e d u r e f o r R e q u e s t i n g C C P I V P 2 3 0 A s s i g n m e n t F i l e ( $ C C P F I L E )
A s s i g n m e n t S t a t e m e n t s (A s s i g n m e n t B u i l d P r o g r a m ) 8 8 O p e r a t i n g I n s t r u c t i o n s w i t h C C P I V P 2 3 O
A s s i g n m e n t C o n t r o l S t a t e m e n t s 9 1 N o r m a l O p e r a t i n g M e s s a g e s 2 3 O
W r i t i n g A s s i g n m e n t C o n t r o l S t a t s m e n t s 9 1 U s e r E r r o r M e s s a g e s 2 3 O
S O U R C P S t a t e m e n t / / S E T S t a t e m e n t / / S Y S T E M S t a t e m e n t
U s e r R e q u i r e m e n t s
S U M M A R Y C H A R T A P P E N D I X C . M E S S A G E S
A P P E N O I X D . D E V I C E S A N D P R O G R A M S
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/ / B S C A L I N E S t a t e m e n t 1 0 3
/ / B S C A T E R M S t a t e m e n t 1 0 6 A S C I I A m e r i c a n N a t i o n a l S t a n d a r d C o d e fo r I n f o r m a t i o n / / M L T A L I N E S t a t e m e n t
/ / M L T A T E R M S t a t e m e n t
1 0 8 I n t e r c h a n g e / / P O R T L I N E S t a t e m e n t ( P r o g r a m N u m b e r
1 1 1 B S C B i n a r y s y n c h r o n o u s c o m m u n i c a t i o n
B S C A B i n a r y s y n c h r o n o u s c o m m u n i c a t i o n s a d a p t e r 5 7 0 4 - S C 2 o n l y ) 1 1 3 B S C C B i n a r y s y n c h r o n o u s c o m m u n i c a t i o n s c o n t r o l l e r i / T E R M N A M E S t a t e m e n t 1 1 6 C C P C o m m u n i c a t i o n s c o n t r o l p r o g r a r r !
/ / D I S K F I L E S t a t e m e n t ' 1 1 7
C P U P r o c e s s i n g u n i t
/ / S Y M F I L E S t a t e m e n t 1 2 2 C R T C a t h o d e r a v t u b e
/ / P R O G R A M S t a t e m e n t 1 2 6 D A D i s p l a y a d a p t e r
P r o g r a m F i n d R o u t i n e ( P r o g r a m N u m b e r 5 7 0 4 - S C 2 o n l y ) 1 3 2 D F C R D i s p l a y f o r m a t c o n t r o l r o u t i n e F o r m a t F i n d R o u t i n e ( P r o g r a m N u m b e r 5 7 0 4 - S C 2 o n l y ) 1 3 3 D F F D i s p l a y f o r m a t f a c i t i t y
D i s k F i l e C l o s e / O p e n F a c i l i t y 1 3 3 D F G R D i s p l a y f o r m a t g e n e r a t i o n r o u r i n e
A s s i g n m e n t L i s t P r o g r a m 1 3 4 D S M D i s k s y s t e m m a n a g e m e n t
/ / L I S T S t a t e m e n t 1 3 5 E B C D I C E x t e n d e d B i n a r y C o d e d D e c i n r a l I n t e r c h a n g e C o d e S a m p l e A s s i g n m e n t B u i l d E x e c u t i o n 1 3 7 E O J E n d o f i o b
S a m p l e A s s i g n m e n t S e t : C a l c u l a t i o n o f M a i n E O T E n d o f t r a n s m i s s i o n 1 4 3 E X l o E x e c u t e in p u t / o u t p u t S t o r a g e S i z e s
U s e r S e c u r i t y D a t a P r o g r a m ( $ C C P A U ) 1 4 9 t / O I n p u t / o u t p u t
I r C f I n t e r a c t i v e C o m m u n i c a t i o n s F e a t u r e C H A P T E R 8 . S Y S T E M H I S T O R Y A R E A C O P Y P R O G R A M '
I O C S I n p u t / o u t p u t c o n t r o l s y s t e m
( P R O G R A M NUMBER 5704-SC2 ONLY) 1 5 1 I O S I n p u t / o u t p u t s u p e r v i s o r
O p e r a t i n g C o n s i d e r a t i o n s 1 5 1 L R C L o n g i t u d i n a l r e d u n d a n c y c h e c k A P P E N D I X A . G E N E R A TI O N C O N T R O L S T A T E M E N T
M F C M M u l t i - f u n c t i o n c a r d m a c h i n e M F C U M u l t i - f u n c t i o n c a r d u n i t 1 5 3 M L M P M u l t i l i n e / m u l t i o o i n t
M L T A M u l t i p l e li n e t e r m i n a l a d a p t e r M R T M u l t i p l e r e q u e s t i n g t e r m i n a l 1 5 9 N E P N e v e r + n d i n g p r o g r a m
O C L O p e r a t i o n c o n t r o l l a n g u a g e 1 6 7 P A S P r o g r a m a p p e n d e d s t o r a g e
P C T P r o g r a m c o n t r o l t a b l e
P F G R P r i n t e r f o r m a t q e n e r a t o r r o u t i n e S U M M A R Y C H A R T
A P P E N D I X B . A S S I G N M E N T C O N T R O L S T A T E M E N T
S U P P O R T E D A N D R E O U I R E D 1 6 9 P R U F P r o g r a m r e q u e s t u n d e r fo r m a l T e r m i n a l s a n d F e a t u r e s S u p p o r t e d 1 6 9 R P O R e q u e s t fo r p r i c e q u o t a t r o n S y s t e m D e v i c e a n d P r o g r a m R e q u i r e m e n t s 1 7 2 S C p S y s t e m c o n t r o l p r o g r a m
1 7 2 S W A S c h e d u l e r w o r k a r e a T P T e l e p r o c e s s i n g
V T O C V o l u m e t a b l e o f c o n t e n r s D e v i c e R e q u i r e m e n t s
T h e c o m m u n i c a t i o n s c o n t r o l p r o g r a m ( C C p ) is a s y s r e m c o n t r o l p r o g r a m m i n g f e a t u r e th a t a l l o w s th e I B M S y s t e m / 3 M o d e l 1 5 t o s u p p o r t a n o n l i n e n e t w o r k o f t e r m i n a l s . CCp e n a b l e s t e r m i n a l s t o c a l l a p p l i c a t i o n p r o g r a m s a s n e e d e d and permits those programs to access a common set of disk f i l e s . l f s u f f i c i e n t m a i n s t o r a g e is a v a i l a b l e , t h e C C p p e r m i t s s e v e r a l a p p l i c a t i o n p r o g r a m s t o b e e x e c u t i n g c o n c u r r e n t l y , t h o u g h i n d e p e n d e n t l y o f o n e a n o t h e r ; th a t i s t h e C C p p r o - v i d e s fo r m u l t i p r o g r a m m i n g w i t h i n o n e p a r t i t i o n .
The CCP is designed to make a communications-based sys-
t e m a s e a s y a n d i n e x p e n s i v e a s p o s s i b l e t o e s t a b l i s h a n d operate. The CCP can be tailored to suit diverse oata pro- c e s s i n g e n v i r o n m e n t s i n v o l v i n g b a t c h a n d o n l i n e a p p l i c a - t i o n s .
Note: lt you are not acquainted with the terms used in t h i s i n t r o d u c t i o n , y o u c a n f i n d t h e m e x p l a i n e d e i t h e r i n Appendix E: Glossary, or in the Data processing Glosnry, G C 2 0 - 1 6 9 9 .
T E R M I N A L O P E R A T O R F A C I L I T I E S
U n d e r c o n t r o l o f t h e C C P , th e o p e r a t o r o f a t e r m i n a l can:
Request programs.
Specify whether a program request should be rejected if t h e p r o g r a m c a n n o t b e e x e c u t e d im m e d i a t e l y , o r w h e t h e r t h e r e q u e s t s h o u l d b e p l a c e d o n a q u e u e .
S p e c i f y th e d i s k f i l e s to b e u s e d b y a p a r t i c u l a r p r o g r a m o r s e r i e s o f p r o g r a m s .
C h a n g e t h e s y m b o l i c n a m e o f t h e t e r m i n a l . send a message to the system operator.
R e l e a s e t h e t e r m i n a l f r o m a p r o g r a m in o r d e r t o e n t e r another program request or command.
Request the operation of a series of tasks via task chain- i n g ( P r o g r a m N . u m b e r 5 7 0 4 - S C 2 o n l v ) .
R e q u e s t s o r t o p e r a t i o n s v i a t h e C C P / D i s k S o r t P r o g r a m . ( P r o g r a m N u m b e r 5 7 9 9 - A T H i s u s e d w i t h SCP 5704-SC1;
5 7 0 4 - S M 7 is u s e d w i t h S C P 5 7 0 4 - S C 2 . )
F i n d n e w o r u p d a t e d p r o g r a m s a n d f o r m a t s ( p r o g r a m N u m b e r 5 7 0 4 - S C 2 o n l v ) .
R e q u e s t t h e o n l i n e t e s t t o d e t e r m i n e w h e t h e r the termi_
n a l i s o p e r a t i n g c o r r e c t l y .
Chapter 1. Introduction
S Y S T E M O P E R A T O R F A C I L I T I E S
T h e s y s t e m o p e r a t o r in i t i a t e s a n d t e r m i n a t e s t h e a c t i v i t y o f t h e C C P a n d c o n t r o l s th e o p e r a t i o n o f t h e c o m m u n i c a t i o n s - based system. After the CCP is loaded into main storage, i t a s k s t h e s y s t e m o p e r a t o r o n e o r m o r e q u e s t i o n s . T h i s a l l o w s th e s y s t e m o p e r a t o r to i d e n t i f y t h e s e t o f f i l e s , p r o g r a m s . t e r m i n a l s , c o m m u n i c a t i o n li n e s , a n d t e r m i n a l names to be used by the CCP on the current run (one or more of these sets were defined prior to the current run of the CCP-see index entry: assignment stage). These ques- t i o n s a l s o a l l o w t h e s y s t e m o p e r a t o r to m o d i f y a s e l e c t e d set to adapt to a particular run of the CCP.
During the operation of the CCP, the system operator c o n t r o l s th e s y s t e m th r o u g h t h e C o n s o l e K e y b o a r d . T h e o p e r a t o r c a n :
o M o n i t o r t h e s t a t u s o f t h e s y s t e m a t a n y m o m e n t . o D e t e r m i n e th e u n f u l f il l e d r e q u e s t s f o r p r o g r a m s o r s y s -
t e m o p e r a t o r r e p l i e s i n t h e s y s t e m a t a n y t i m e . Send messages to terminals.
C h a n g e t h e s t a t u s o f t e r m i n a l s o n t h e s y s t e m . C a n c e l , s u s p e n d , a n d r e s u m e a c t i v i t i e s o f p r o g r a m s . C h a n g e t h e a c t u a l te r m i n a l r e f e r r e d t o b y a t e r m i n a l n a m e .
R e q u e s t t h e o n l i n e t e s t o f t e r m i n a l s to d e t e r m i n e w h e t h e r they are operating correctly.
C l o s e C C P f i l e s .
O p e n t h e p r e v i o u s l y c l o s e d C C P fi l e s . S h u t d o w n C C P .
C h a n g e i n t e r v a l p o l l i n g t i m e s . R e c o v e r f r o m t e r m i n a l e r r o r s . Save trace table information.
Activate or deactivate automatic retries to terminals in error recovery and control the frequency of retries ( P r o g r a m N u m b e r 5 7 0 4 - S C 2 o n l y ) .
I n i t i a t e o r t e r m i n a t e th e C C P lo a d a b l e t r a c e .
O
o
a
a
a
I n t r o d u c t i o n
T h e s y s t e m o p e r a t o r c a n a l s o p e r f , r r m s o m e o f t h e f u n c t i o n s o A u t o m a t i c t r a n s l a t i o n o f t r a n s m i s s i o n d a t a c o d e s of a terminal operator such as request programs, enter com-
m a n d s , a n d , f o r P r o g r a m N u m b e r 5 7 0 4 - S C 2 , f i n d p r o g r a m 5 o D y n a m i c , p r o g r a m - c o n t r o l l e d a l l o c a t i o n a n d d e a l l o c a -
a n d f o r m a t s . t i o n o f t e r m i n a l s
Because of the extent of the control exercised by the sys- . Access to communications l/O error or exception
t e m o p e r a t o r , h e o r s h e m u s t b e t h o r o u g h l y t r a i n e d i n t h e i n f o r m a t i o n o p e r a t i o n o f t h e C C P , a p p l i c a t i o n : ; o f t h e C C P i n t h e
i n s t a l l a t i o n , a n d t h e s p e c i f i c ta s k s to p e r f o r m u n d e r c o n t r o l o I n t e r a c t i o n w i t h e x t e r n a l b u f f e r s ( P r o g r a m N u m b e r
o f t h e c c P . 5 7 0 4 - S C 2 o n t v )
P R O G R A M M I N G F A C I L I T l E S
P r o g r a r n s t h a t r u n u n d e r t h e C C P c a n b e w r i t t e n in a n y o f f o u r p r o g r a m m i n g l a n g u a g e s :
r R P G I I o C O B O L
. I n i t i a t i o n o f a t a s k ( i n c l u d i n g a s o r t t a s k ) f r o m a n a c t i v e t a s k v i a t a s k c h a i n i n g ( P r o g r a m N u m b e r 5 7 0 4 - S C 2 o n l y )
D E V I C E S A N D P R O G R A M S S U P P O R T E D
T h e t e r m i n a l d e v i c e s , s y s t e m d e v i c e s , a n d s y s t e m p r o g r a m s r e q u i r e d a n d s u p p o r t e d b y t h e C C P a r e l i s t e d in A p p e n d i x D .
o F O R T R A N l V
E S T A B L I S H I N G A N D O P E R A T I N G T H E C C P o B a s i c A s s e m b l e r
T h e C C P c a n b e t a i l o r e d to s u i t e a c h u n i q u e o p e r a t i n g e n - A l t h o u g h t h e d e s i g n o f p r o g r a m s l v r i t t e n f o r t h e C C P m i g h t v i r o n m e n t . E s t a b l i s h i n g a n d o p e r a t i n g t h e C C P i n a p a r t r - b e d i f f e r e n t f r o m t h o s e t h e p r o g r a m m e r h a s b e e n w r i t i n g , c u l a r e n v i r o n m e n t is a c c o m p l i s h e d i n t h r e e s t a g e s : p r o g r a m m i n g s t a t e m e n t s u s e d fo r t e r m i n a l i n p u t / o u t p u t
a r e a l r e a d y fa m i l i a r t o p r o g r a m m e r s : a G e n e r a t i o n o I n C O t I O L o r F O R T R A N : t h e c a l l s t a t e m e n t . . A s s i g n m e n l
. I n R P G l l : e i t h e r t h e e x i t o p e r a t i o n o r a s p e c i a l f i l e . . O p e r a t i o n a l s y s t e m s t a r t u p r I n B a s i c A s s e m b l e r : m a c r o i n s t r u c t i o n s t h a t c a n b e
processed by the disk system rnanagement macros" Generation Stage
W i t h e a c h r e q u e s t f o r t e r m i n a l l / O , t h e p r o g r a m m e r p r o v i d e s C C P g e n e r a t i o n i s t h e p r o c e s s b y w h i c h a u s e r c r e a t e s a n a l i s t o f p a r a m e t e r s t h a t t e l l t h e C C P w h i c h s p e c i f i c i n d i v i d u a l v e r s i o n o f t h e C C P . T h e p u r p o s e o f g e n e r a t i o n r s o p e r a t i o n to p e r f o r m , w h i c h t e r m i n a l t o u s e , a n d w h a t t o c r e a t e a s e t o f C C P o b j e c t m o d u l e s a n d s u b r o u t i n e s , d a t a a r e a to u s e . u n i q u e t o t h a t u s e r ' s r e q u i r e m e n t s , o n t h e u s e r ' s d i s k p a c k .
T h e p r o c e s s o f q e n e r a t i o n i n v o l v e s : T h e C C P a l l o w s th e p r o g r a m m e r t o i d e n t i f y t e r m i n a l s b y
s y m b o l i c n a m e s . l f a p a r t i c u l a r te r m i n a l i s u n a v a i l a b l e f o r 1 . D e s c r i b i n g t h e t y p e o f e q u i p m e n t to b e u s e d b y t h e a n y r e a s o n , t h e s y s t e m o p e r a t o r c a n r e a s s i g n t h e s y m b o l i c c o m m u n i c a t i o n s s y s t e m a n d t h e f a c i l i t i e s t h a t s h o u l d n a m e t o a d i f f e r e n t t e r m i n a l . T h u s , t h e p r o g r a m n e e d n o t b e i n c l u d e d in t h a t s y s t e m .
b e c h a n g e d o r r e c o m p i l e d t o a d d r e s s a d i { f e r e n t t e r m i n a l .
2 . C r e a t i n g a s e t o f c o n t r o l r o u t i n e s w h o s e s p e c i f i c c o n - O t h e r f a c i l i t i e s o f f e r e d b y t h e C C P t o t h e p r o g r a m m e r a r e : t e n t m a y b e u n i q u e t o t h e u s e r ' s i n s t a l l a t i o n . o A c c e s s t o t h e n a m e o f t h e t e r m i n a l t h a t r e q u e s t e d t h e 3 . J o i n i n g t h e r o u t i n e s b y a l i n k - e d i t i n g p r o c e s s .
program
4 . C o p y i n g a p p r o p r i a t e a d d i t i o n a l s u p p o r t i n g r o u t i n e s , . A c c e s s t o a t t r i b u t e s o f i n d i v i d u r a l t e r m i n a l s
5 . I n i t i a l i z i n g t h e a s s i g n m e n t f i l e u s e d b y t h e a s s i g n m e n t . S u p p o r t f o r o v e r l a y p r o g r a m s s t a g e a n d t h e o p e r a t i o n a l s t a g e .
Assignment Stage
A s s i g n m e n t i s a s p e c i a l , b r i e f C C P r u n d u r i n g w h i c h t h e u s e r s p e c i f i e s o n e o r m o r e s e t s o f s p e c i f i c e n v i r o n m e n t s in w h i c h t h e C C P w i l l r u n . E a c h s e t in c l u d e s :
a S p e c i f i c i t e m s o f i n f o r m a t i o n p e r t a i n i n g t o t h e e n t i r e CCP, such as the current password.
o P r o g r a m s t h a t c a n b e r u n u n d e r t h e C C p a n d t h e r e s o u r c e s e a c h r e q u i r e s .
o F i l e s th a t a r e a c c e s s i b l e t o e a c h p r o g r a m a n d h o w t h e y are to be accessed.
o T h e c u r r e n t l i n e / t e r m i n a l conf iguration.
T h e a s s i g n m e n t r u n n e e d b e r e p e a t e d o n l y w h e n t h e u s e r w i s h e s t o c h a n g e s o m e o f t h e s p e c i f i c in f o r m a t i o n g i v e n in a p r e v i o u s a s s i g n m e n t r u n .
Operational Stage
The operational stage begins with operational startup, w h e n t h e C C P is l o a d e d in t o m a i n s t o r a g e . D u r i n g s t a r t u p , t h e C C P r o u t i n e s o p e n d i s k f i l e s , a < l a p t e r s , a n d c o m m u n i c a - t i o n l i n e s a n d c o m p l e t e v a r i o u s ta b l e s a n d c o n t r o l b l o c k s . D u r i n g o p e r a t i o n , th e C C P p e r f o r m s th e f u n c t i o n s r e q u e s r - ed by terminal operators and the svstem operator,
e x e c u t i n g a p p l i c a t i o n p r o g r a m s a s r l i r e c t e d b y t h o s e ope rators.
T h e o p e r a t i o n a l s t a g e i s c o n c l u d e d b y s h u t d o w n . w h i c h i s i n i t i a t e c l b y t h e s y s t e m o p e r a t o r . D u r i n g s h u t d o w n , th e C C P a l l o w s c u r r e n t l y e x e c u t i n g p r o g r a m s t o c o m p l e t e p r o c e s s i n g , t h e n c l o s e s c o m m u n i c a ' t i o n l i n e s , a d a p t e r s , a n d f i l e s .
CCP TASKS
E a c h b o d y o f c o d e . s u c h a s a n a p p l i c a t i o n p r o g r a m , e x e c u r - i n g i n d e p e n d e n t l y i r r t h e C C P p r o g r a m p a r t i t i o n i s c o n s i d - ered a task. lt is possible for two or more copies of the s a m e p r o g r a m to b e e x e c u t i n g c o n c u r r e n l l y a n d i n d e p e n d - e n t l y u n d e r t h e C C P ; in t h i s c a s e , e a c h c o p y i s c o n s i d e r e d a task.
Tasks are identified as either user tasks or system tasks (see CCP System Operator's Guide, for uses of the task i d e n t i f i c a t i o n ) . A n e x a m p l e o f a u s e r ta s k i s a n i n q u i r y p r o g r a m , lo a d e d in t o m a i n s t o r a g e b y r e q u e s t f r o m
e i t h e r a t e r m i n a l o p e r a t o r o r t h e s y s t e m o p e r a t o r ; a n e x a m p l e o f a s y s t e m ta s k i s t h e C C P c o m m u n i c a t i o n s m a n a q e m e n t task, which processes requests for terminal l/O.
The management of tasks, as performed by the CCp, permits t a s k s t o b e i n i t i a t e d a n d te r m i n a t e d i n d e p e n d e n t l y a n d to o p e r a t e c o n c u r r e n t l y . W h e n u s e r t a s k s r u n c o n c u r r e n t l y , results are identical to those that would occur had each t a s k ru n a l o n e . U n d e r C C P , 1 - 1 5 u s e r t a s k s c a n e x e c u r e concurrently; tasks can be from 4K to 32K bvtes.
R E L A T I O N S H I P T O O T H E R P R O G R A M S
F i g u r e 1 i l l u s t r a t e s t h e r e l a t i o n s h i p s b e t w e e n t h e C C P a n d disk system management and between the CCP and a p p l i c a t i o n p r o g r a m s .
Disk System Management (DSMI
T h e C C P o p e r a t e s i n c o n j u n c t i o n w i t h D S M a n d u s e s t h e f o l l o w i n g f a c i l i t i e s o f D S M w h e r e v e r p o s s i b l e :
. DSM Supervisor: Used for program loading, disk and u n i t r e c o r d p h y s i c a l l / O c o n t r o l (l O S ) . O n P r o g r a m N u m b e r 5 7 0 4 - S C 2 , u s e e n q u e u e a n d d e q u e u e . Disk and Unit Record Data Management: Used for l o g i c a l c o n t r o l c f d i s k a n d u n i t r e c o r d l / O .
DSM Console Management' Certain CCP display transi- e n t s ru n i n t h e D S M tr a n s i e n t a r e a a n d in t e r f a c e d i r e c t l v w i t h D S M c o n s o l e m a n a q e m e n t t r a n s i e n t s .
MLTA and/or MLMP /OCS: The CCP incorporates e i t h e r o r b o t h o f t h e s e S y s t e m / 3 c o m m u n i c a t i o n s l / O p r o g r a m s , d e p e n d i n g u p o n th e l i n e c o n f i g u r a t i o n o f t h e s y s t e m : t h e m u l t i p l e l i n e te r m i n a l a d a p t e r ( M L T A )
R P Q (r e q u e s t f o r p r i c e q u o t a t i o n ) p r o g r a m f o r s t a r t - s t o p t e r m i n a l ; t h e m u l t i l i n e / m u l t i p o i n t ( M L M P ) I O C S f o r b i n a r y s y n c h r o n o u s t e r m i n a l s a t t a c h e d t o S y s t e m / 3 b y t h e b i n a r y s y n c h r o n o u s c o m m u n i c a t i o n s a d a p t e r ( B S C A l i n e s 1 a n d 2 ) . y o u r c o m m u n i c a t i o n s p r o g r a m s d o n o t ( a n d r n u s t n o t ) u s e t h e c o m m u n i c a t i o n s I O C S d i r e c t l y ; t h e C C P c a l l s t h e a p p r o p r i a t e I O C S w h e n n e e d e d . b a s e d o n t h e i n s t r u c t i o n s y o u i s s u e i n y o u r p r o g r a m .
BSCC IOCS: The CCP incorporates this liO support if B S C l i n e s 3 o r 4 a r e u s e d . T h i s l/ O s u p p o r t i s p a r t o f D S M a n d c a n b e u s e d i f B S C C w a s s p e c i f i e d d u r i n g s y s t e m g e n e r a t i o n . T h i s s u p p o r t i s u s e d o n l y b y C C P . S I O C IO C S : T h e C C P i n c o r p o r a t e s t h i s l / O s u p p o r t i f a n R P O (r e q u e s t f o r p r i c e q u o t a t i o n ) f o r S I O C c h a n n e l c o n n e c t e d s y s t e m s i s u s e d . F o r a d d i t i o n a l information, see l8M System/3 Model l5D Channel Connected Systems Program Reference and Logic M a n u a l , G C 2 1 5 i 9 9 ( P r o g r a m N u m b e r 5 7 0 4 - S C 2 o n l y ) .
I n t r o d u c t i o n 3
S u p e r v i s o r A r e a
U s e r a p p l i c a t i o n p r o g r a m
C o m m u n i c a t i o n s C o n t r o l P r o q r a m
C o m m u n ic a t i o n c o n t r o l p r o g r a m under control of System/3 d i s k s y s t e m m a n a g e m e n t
U s e r a p p l i c a t i o n p r o g r a m s r u n n i n g u n d e r C C P
U s e r a p p l i c a t i o n p r o g r a m P r o g r a m P a r t i t i o n 1
a m P a r t i t i o n 2 Program Partition 3
( P r o g r a m N u m b e r 5 7 0 4 - S C 2 o n l y )
Figure 1. Relationships between System/3 Disk System Management, the Communications Control Program, and User Application programs
Existing Communications Programming Support
T h e R P G l l t e l e c o m m u n i c a t i o n s f e r a t u r e , w h i c h p r o v i d e s s u p p o r t f o r b a t c h t e r m i n a l s in R P G l l , i s n o t a p a r t o f t h e C C P a n d c a n n o t b e u s e d u n d e r t h e C C P . A p p l i c a t i o n prJgrams using these features can, however, be executed in a n o t h e r p r o g r a m p a r t i t i o n f r o m t h e C C P a s lo n g a s t h e i r u s e o f c o m m u n i c a t i o n li n e s d o e s n o t c o n f li c t w i t h t h e C C P .
Application Programs
A p p l i c a t i o n p r o g r a m s c a n e x e c u t e u n d e r c o n t r o l o f t h e C C P o r , i n a n o t h e r p a r t i t i o n , u n d e r c o n t r o l o f D S M .
T e l e c o m m u n i c a t i o n a p p l i c a t i o n p r o g r a m s t h a t e x e c u t e u n d e r t h e C C P a r e o n e s t e p r e m o v e d fr o m c o n t r o l b y D S M . T h e y a r e l o a d e d b y t h e C C P a n d r e c e i v e c o n t r o l f r o m t h e CCP. Requests by these programs for system services are received and scheduled by the CCP. Some requests are performed by the CCP; some are passed from the CCP to DSIV1 to be performed.
A t e l e c o m m u n i c a t i o n s a p p l i c a t i o n p r o g r a m th a t e x e c u t e s i n a n o n - C C P p a r t i t i o n m u s t i n c l u d e th e c o m m u n i c a t i o n s
I O C S r o u t i n e s it r e q u i r e s . l t s u s e o f c o m m u n i c a t i o n s li n e s m u s t n o t c o n f l i c t w i t h t h e C C P .
S o m e n o n c o m m u n i c a t i o n s a p p l i c a t i o n p r o g r a m s n o t
o r i g i n a l l y w r i t t e n t o r u n u n d e r C C P c o n t r o l c a n b e e x e c u t e d under the CCP. These programs can be requested from the s v s t e m o p e r a t o r ' s c o n s o l e o r f r o m a t e r m i n a l i f t h e y d o n o t v i o l a t e a n y o f t h e r e s t r i c t i o n s p l a c u ' d u p o n C C P p r o g r a m s a n d i f t h e y a r e d e f i n e d in a n a s s i g n m e n t s e t . l f s u c h a p r o g r a m h a s n o t b e e n r e w r i t t e n t o r e l e a s e t h e r e q u e s t i n g t e r m i n a l , th e n t h e t e r m i n a l is n o t I ' r e e t o e n t e r a n o t h e r c o m m a n d o r p r o g r a m r e q u e s t u n t i l t h e r e q u e s t e d p r o g r a m term i nates.
N o n c o r n m u n i c a t i o n s a p p l i c a t i o r r p r o g r a m s c a n b e e x e c u t e d i n a n o n - C C P p r o g r a m p a r t i t i o n w f r i l e th e C C P is o p e r a t i n g i f t h e y d o n o t c o n f l i c t w i t h t h e C C P i n t h e i r u s e o f s v s t e m r e s o u r c e s ( d i s k fi l e s a n d u n i t r e c o r d d e v i c e s ) .
System Programs
S y s t e m p r o g r a m fa c i l i t i e s r s u c h a s u r i l i t i e s , c o m p i l e r s , s o u r c e li b r a r y G e t / P u t , o r S Y S P R I N T ) c a n n o t b e r u n u n d e r CCP. Sorne system ltrograms can Lrc run in the non-CCp p a r t i t i o r t ( s ) w h i l e C C P i s e x e c u t i n g , a n d s o m e d e d i c a t e d s y s t e m p r o g r a m s r e q u i r e th a t C C P b e s h u t d o w n b e f o r e t h e y c a n b e e x e c u t e d . F o r m o r e i r r f o r m a t i o n , s e e th e appropriate SCP reference manual listed under Related Publications in the Preface.
' T h e
s p o o l f il e c o p y p r o g r a m ( $ O C O P Y ) is a n e x c e p t i o n . $ O C O P Y r u n s u n d e r c o n t r o l o f S C P a n d . if i t s n a m e r s c h a n g e d s o t h a t i t b e E i n s w i t h s o n r e t h i n g o t h e r t h a n $ , $ O C O P Y a l s o r u n s u n d e r c o n t r o l o f C C P { M o d e t 1 5 5 7 0 4 " S C 2 o n l v ) .
I n t r o d u c t i o n
To the operator of a terminal, the system is a resource to h e l p h i m a c c o m p l i s h h i s ta s k s " T h e te r m i n a l o p e r a t o r rnight think of the system as belonging to him or her alone, unless the combined demands upon the system are great enough to cause delay in its responsiveness. All contention among terminal operators for use of the system is managed by CCP.
T h e C C P d i s t i n g u i s h e s t w o t y p e s o f t e r m i n a l s :
Command terminals, which can request services of the CCP including the running of application programs.
Data terminalq which cannot request services, and are used only as directed by the application programs.
In order to call for application programs, the command terminal operator must first sign on to the CCP. A sign-on request is a message initiated by the terminal operator signifying the wish to request services of the CCP. lf the system has a password security feature (an option selected during the CCP generation-see index entry initial model, the terminal operator must correctly enter a password with the sign-on request.
O n c e a t e r m i n a l o p e r a t o r i s in c o m m u n i c a t i o n w i t h t h e requested application program. he or she enters data as required by the program. The sequence of operations at the terminal, and the format of data sent to and from it, are entirely directed by the application program. The terminal operation continues to be directed by the applica- tion program until that program releases it. However, the o p e r a t o r , w h i l e s e n d i n g d a t a fr o m t h e t e r m i n a l t o t h e a p p l i - cation program, can reestablish cornmunication with the C C P i n o r d e r to :
a Send a message to the system operator and then resume sending data to the program.
o Release his terminal from control of the program.
When a terminal operator f inishes making a series of re- quests for services of the CCP. he or she normally signs off t h e t e r m i n a l . T h i s a c t i o n re s t o r e s t h e t e r m i n a l t o a n i n i t i a l status, such that it must be signed on again (with a pass- word, if that option was chosen) before it can request services of the CCP.
Cirapter 2. Using the CCP fnom a Terminal
H O W T H E T E R M I N A L O P E R A T O R R E O U E S T S A P R O G R A M
W h e n a c o m m a n d t e r m i n a l i s n o t i n u s e , it i s c o n t i n u a l l y monitored by the control prograrn for a request. The t e r m i n a l o p e r a t o r c a l l s fo r a n a p p l i c a t i o n p r o g r a m to p e r f o r m a s p e c i f i c fu n c t i o n b y s i m p l y e n t e r i n g th e p r o g r a m n a m e a t t h e t e r m i n a l . T h e C C P t h e n a t t e r n o t s to l o a d a n d e x e c u t e t h e p r o g r a m a n d t o p u t t h a t p r c g r a m in c o m m u n r c a t i o n w i t h t h e t e r m i n a l o p e r a t o r . F r o m t h e n u n t i l t h e completion of the program, the interaction between the terminal operator and the system is ijictatecl by that program.
W h e n t h e a p p l i c a t i o n p r o g r a m c o m p l e t e s e x e c u t i o n , it y i e l d s c o n t r o l o f t h e t e r m i n a l t o t h e C C F . T h e C C P o n c e a g a i n m o n i t o r s t h e t e r m i n a l f o r a t e r m i n a l c o r n m a n r l s u c h as a program request. The next program request does not have to be for the same program.
E a c h te r m i n a l o p e r a t o r m u s t b e t r a i n e d in t h e f u n c t i o n s h e o r s h e c a n c a l l u p o n a n d i n t h e p r o c e d u r e s f o r i n t e r a c t i n g w i t h t h e a p p l i c a t i o n p r o g r a m s t h a t p e r f o r m t h o s e fu n c t i o n s .
H O W T H E T E R M I N A L O P E R A T O R R E O U E S T S S Y S T E M S E R V I C E S
W h i l e m o n i t o r i n g f o r p r o g r a m r e q u e s t s , t h e C C P c a n a l s o respond to commands to perform services f or the ternrinal.
The operator can specify ahead of time what the systern's r e s p o n s e s h o u l d b e w h e n i t i s u n a b l e to c o r n p l y i m m e d i a t e l y with his request for a program. The systenr might be temporarily too busy with requests from other operators.
B y c o m m a n d , h e c a n c h o o s e o n e o f t h e { n l l o w i n g r e s p o n s e s : o T h e s y s t e m d e n i e s th e r e q u e s t a n d a l l o w s h i m t o r n a k e
some other request.
o The system holds the request and honors it as soon as possible.
Once the operator of a terminal has specif ied one of these requests. the CCP handles all program requests {rom that t e r m i n a l a c c c l r d i n g l y u n t i l t h e o p e r a t o r s p e c i f i e s d i f f e r e n t l y .
U s i n g t h e C C P F r o m a T e r m i n a l 7
A f i l e s p e c i f i c a t i o n a l l o w s th e o p e r a t o r to s p e c i f y th e d i s k d a t a f i l t : s th a t a r e t o b e a c c e s s e d l c y p r o g r a m s h e o r s h e r e q u e s t s , i f t h o s e p r o g r a m s a r e w r i t t e n t o a c c e p t th e s p e c i f i - c a t i o n . V / i t h i n t h e i n f < i r m a t i o n s , y s t e n l , t h e r e m a y b e s e v e r a l f i l e s c o n t a i n i r r g s i m i l a r d a t a i n t h e s a m e fo r m a t . A s c h o o l s y s t e m , fo r e x a r n p l e , m i g h r t h a v e a s e p a r a t e s t u d e n t r e c o r d s f i l e f o r e a c h s c h o o l , A n a p p l i c a t i o n p r o g r a m requeste(J by the oper€tor might have been written to access a n y o n e o f t h e s e fi l e s , b u t t h e p r o g r a m m u s t b e t o l d w h i c h f i l e t o u s e o n a p a r t i c u l a r ru n . A f i l e s p e c i f i c a t i o n c o n r m a n o i s s u e d b y t h e t e r m i n a l o p e r a t o r a p p l i e s to a l l p r o g r a m s r e q u e s t e d a t t h a t t e r m i n a l u n t i l a c o n t r a d i c t o r y c o m m a n o i s i s s u e d .
A n o t h e r c o m m a n d p e r m i t s th e t e r r m i n a l o p e r a t o r to s e n d a message to the system operator, requesting some action to b e t a k e n .
T h e c o m m a n d s d i s c u s s e d s o f a r a r e i s s u e d t o t h r e C C P w h i l e i t i s m o n i t o r i n g a t e r r n i n a l f< l r r e c ; u e s t s . O n c e a t e r m i n a l i s i n t e r a c t i r r g w i t h a n a p p i i c a t i o n p r o g r a m , h o w e v e r , th e i n p u t f r o m t h a t t e r r n i n a i is n r c a n i n g f u l o n l y t o t h e a p p l i c a t i o n p r o g r a m , w i t h o n e e x c e p t i o n . T l - r e C C P c h e c k s e a c n message from a termininl to a pro{lram for a certain string o f c h a r a c t e r s d e f in e d i r r y o u r s v s l e m . W h e n i t d e t e c t s t h e s e c h a r a c t e r s i n a m e s s a g e , t h e C C P in t e r p r e t s t h e rnessage as an attempt by the terrninal operator to escape f r o r r r c o n t r o l o f t h e a p p l i c a t i o n p r o g r a m a n d c o m m u n i c a t e d i r e c t l y w i t h t h e C C P . A t t h i s p o i r r t , th e C C P a c c e p t s a r e q u e $ t f r o m t h e o p e r a t o r to r e l e i e s e t h e t e r m i n a l f r o m t h e c o n t r o l o f t h e a p p l i c a t r o n p r o g r a r n , o r t o s e n d a m e s s a g e t o t h e s y s t e m o p e r a t o r , l f t h e r e q u e s t w a s t o s e n d a m e s s a g e , t h e t e r m i n a l o p e r a t o r c a n a s k th e C C P to r e s u m e e x e c u t i o n o f t h e a p p l i c a t i o r r p r o g r a m a f t e r t h e m e s s a g e i s s e n t .
. T E R M I N A L M O D E S
T l - r e r e a r e t w o c l a s s e s o f t e r m i n a l s d e f in e d p r e v i o u s l y , b a s e d o n w h e t h e r o r n o t t h e t e r m i n a l s a r e c a p a b l e o f e n t e r i n g c o m m a n r l s t o t h e C C P : c o m m a n r l te r n r i n a i s a n d d a t a t e r - n t i r t a l : ; ( s e r A n p e n d i x E . G l c x ; a r y l . D a t a t e r m i n a l s are c a p a b l e o n l y o f t r a n s r n i t t i n g o r r e , c e i v i n g d a t a u n d e r c o n t r o l o f a n a p p l i c a t i o n p r o g r a n r ; t h e y a r e n o t c a p a b l e o f c c l m - m a n d i n g C C P s e r v i c e s . l y ' J h e n d a t a t e r m i n a l s a r e n o r c o m m u n i c a t i n g w i t h a n a p p l i c a t i o n p r o g r a m . th e y a r e i n a s t a n d L ) y m o d e { r r c t p o l l e d b y t h e C C P f o r i n p u t ) . B e c a u s e t h e o p r e r a t o r o f a r J a t a t e r m i n a l d o e s n o t i n t e r a c t w i t h t h e C C P , th i s ; c h a p t e r d e a l s o n i y w i t h t h e o p e r a t i o n o f c o m m a n d L e r m i r r a l s ; .
A t t h n u g h t h e r e a r e o f J e f a t i n g d i f f e r e r r c e s a j - r . l o n g t h e v a r i o u s t e r m i r r a l t y F r e $ t h a t c a n b e u s e d a s c o m m a n d t e r m i n a l s , t h e f u n c t i o n s t h a t c a n b e 0 e r f o r n r e d tr v t h e r n a r e t h e s a m e .
T h e p r i m a r y f u n c t i o n o f a n y c o m m a n d t e r m i n a l i s t o r e - q u e s t th e e x e c u t i o n o f a p p l i c a t i o n p r o g r a m s . A l l o f t h e a c t i v i t i e s a t e r m i n a l o p e r a t o r p e r f o r m s a r e r e l a t e d to t h a t f u n c t i o n .
lnitial Mode
W h e n a c o m m a n d t e r r n i n a l is o n l i n e , it i s p h y s i c a l l y a t - t a c h e d to t h e s y s t e m a n d l o g i c a l l y a t t a c h e d to t h e C C P . T h e C C P m o n i t o r s i t c o r r t i n u o u s l y f o r p r o g r a m r e q u e s t s o r other commands. Before a program can be requested, the o p e r a t o r m u s t f i r s t s i g n o n a t t h e t e r m i n a l . S i g n i n g o n i n v o l v e s c o m m u n i c a t i o n b e t w e e n th e t e r m i n a l o p e r a t o r a n d t h e C C P . B e f o r e a n d d u r i n g t h i s c o m m u n i c a t i o n , th e terminal isin initial mode. Commands for CCP services o t h e r t h a n s y s t e m o p e r a t o r c o m m u t l i c a t i o n c a n n o t b e i s s u e d f r o m a t e r m i n a l w h e n i t i s i n i n i t i a l m o < J e . T h e e n d o f i n i t i a l m o d e o c c u r s w h e n t h e t e r m i n a l o p e r a t o r is s u c c e s s f u l l y s i g n e d o n .
F r o m t h e p o i n t o f v i e w o f t h e t e r m i n a l o p e r a t o r , s i g n i n g o n m a y b e a s s i m p l e a s e n t e r i n g th e s i g n - o n c o m m a n d . H o w - e v e r , if a c c e s s t o t h e s y s t e m fr o m a t e r m i n a l m u s t b e l i m i t e d t o c e r t a i n a u t h o r i z e d p e o p l e , th e s i g n - o n p r o c e d u r e c a n i n v o l v e p r o v i d i n g a d d i t i o n a l in f o r m a t i o n r e q u i r e d b y a security feature. The security feature can be either the password security option provided by the CCP (see index entry: pa$sword security aptionl or a routine written by the user to control access to the system in some other way.
Command Mode
A f t e r a t e r m i n a l o p e r a t o r is s u c c e s s f u l l y s i g n e d o n , t h e terminal is in command mode. This means the operator c a n r e q u e s t t h e C C P t o l o a d a n d e x e c u t e p r o g r a m s a n d c a n i s s u e r e l a t e d c o m m a n d s . O n c e a t e r m i n a l i s i n c o m m a n d m o d e . i t r e m a i n s in c o m m a n d n r o d e u n t i l a p r o g r a m r e - quest is made from the terminal (see Terminal Operator Commandsl, the operator signs off, or the system operator v a r i e s t h e t e r m i n a l o f f l i n e .
Data Mode
O n c e t h e t e r m i n a l o p e r a t o r is s u e s a c o m m a n d t o l o a d a n d e x e c u t e a u s e r a p p l i c a t i o n p r o g r a m , th e C C P lo a d s th e p r o g r a m a n d g i v e s it c o n t r o l . A t t h a t p o i n t , t h e t e r m i n a l e n t e r s d a t a m o d e ; l l \ a t i s , t h e t e r m i n a l i s i n c o m m u n i c a t i o n w i t h t h e a p p l i c a t i o n p r o g r a m it s e l f . T h e n a t u r e o f t h e c o m m u n i c a t i o n is , o f c o u r s e , d e t e r m i n e d b y t h e a p p l i c a t i o n p r o g r a r n . N o r n r a l l y . th e t e r m i n a l r e m a i n s in d a t a m o d e u n t i l t h e a p p l i c a t i o n p r o g r a r n c o m p l e t e s p r o c e s s i n g o r r e l e a s e s t h e t e r m i r r a l . A t t h a t t i m e . t h e t e r m i n a l i s a g a i n p l a c e d in c o m m a n d r n o d e a n d i s a b l e t o i s s u e a n o t h e r rrrogram request.
Command lnterrupt Mode
The operator of a terminal need not wait until a program completes its job in order to interrupt it. By entering a string of six characters that are significant to the CCp ( d e t e r m i n e d b y t h e u s e r a t g e n e r a t i o n t i m e ) , h e c a n in d i c a t e that he wants to escape from data mode and enter command interrupt mode (see index entry: data mode escape). While in this mode, he can send messages to the system operator.
resume execution of the program, or release his terminal completely from the control of the program (at which p o i n t the terminal i s a g a i n i n c o m m a n d m o d e ) .
T E R M I N A L O P E R A T O R C O M M A N D S
Two logical groups of terminal operator commands can be i s s u e d a f t e r s i g n - o n . F i r s t , w h i l e th e t e r m i n a l i s i n
command mode, before a program request is actually made, the terminal operator can issue various commands pertain_
ing to the subsequent program request:
Tell the CCP how to handle his request if it cannot be honored immediately (see eueue/No_eueue Commandsl.
lssue commands that indicate which files are to be accessed by program requests (see Fite Specification Commandl.
T e l l th e C C P b y w h a t n a m e , o f a s e t o f n a m e s d e f i n e d a s valid, the terminal should be known to the prograrn he is requesting (see Name Commandl.
Send a message to the system operator (see Mesage Commandl. This can also be done prior to sign-on.
T h e s e c o n d g r o u p o f c o m m a n d s i s u s e d d u r i n g c o m m a n d interrupt mode. After data mode escape, the terminal operator can:
o Send one or more messages to the system operator (by u s i n g t h e m e s s a g e c o m m a n d ) .
o Release the terminal from control of the application program (see Release Commandl .
o Resume execution of the program (see Run Commandl.
Sign-On Command (/ON)
T h e s i g n - o n c o m m a n d n o t i f i e s th e C C p t h a t t h e t e r m i n a l operator wishes to begin making requests of the system. lf the system uses a security feature, the sign_on command m u s t b e a c c o m p a n i e d b y o n e o f t h e f o l l o w i n q :
1. The current password required by the CCp password
security feature.
2. lnformation required by a user-written sign-on rou_
t i n e .
The CCP logs every sign-on attempt on the system opera- t o r ' s c o n s o l e a n d i n d i c a t e s i f s i g n - o n w a s s u c c e s s f u l . lf t h e s i g n - o n w a s s u c c e s s f u l , t h e C C P n o t i f i e s th e t e r m i n a l
o p e r a t o r a n d a l l o w s h i m t o e n t e r a c o m m a n d . l f the sign_on was not successful. the CCP allows the terminal operator to a t t e m p t t o s i g n o n a g a i n .
W h i l e a t e r m i n a l i s i n i n i t i a l m o d e . th e name of the terminal can be changed. The system operator can change the name b y u s i n g th e a s s i g n c o m m a n d . S i g n o n r e s t o r e s t h e o r i g i n a l n a m e o f t h e t e r m i n a l .
O n c e t h e o p e r a t o r s i g n s o n a t t h e t e r m i n a l , h e c a n m a k e a n y n u m b e r o f r e q u e s t s w i t h o u t s i g n i n g o n a g a i n . H o w e v e r , i f t h e t e r m i n a l o p e r a t o r le a v e s t h e t e r m i n a l u n a t t e n d e d a n d access to the terminal is restricted by a security feature, he should sign off when he leaves (see Sign-Off Commandl. lt h e s i g n s o f f , h e m u s t s i g n o n a g a i n w h e n h e w a n t s to use the t e r m i n a l a g a i n .
Queue/No-Queue Commands (/e and /NOOI
T h e q u e u e o r n o - q u e u e c o m m a n d i n d i c a t e s h o w t h e C C p i s t o h a n d l e p r o g r a m r e q u e s t s f r o m t h i s t e r m i n a l w h i c h c a n n o t b e h o n o r e d i m m e d i a t e l v :
Command Meaning
/O The operator waits for the program to start.
T h e C C P p l a c e s t h e r e q u e s t o n a q u e u e a n d h o n o r s it a s s o o n a s p o s s i b l e .
/NOO The operator does not wait if the program
cannot start immediately. The CCp rejects the c o m m a n d i f i t c a n n o t b e h o n o r e d im m e d i a t e l y a n d a l l o w s th e o p e r a t o r to e n t e r a n o t h e r r e q u e s t .
U s i n g th e C C P F r o m a T e r m i n a l 9
A q u e u e o r n o - q u e u e c o m m a n d r e m a i n s i n e f f e c t u n t i l th e t e r m i n a l o p e r a t o r e n t e r s a d i f f e r e n t q u e u e o r n o - q u e u e c o m m a n d o r u n t i l h e s i g n s o f f . l f n e i t h e r a q u e u e n o r a no-queue command is entered at the terminal, the CCp assumes the no-queue option. For tasks requested via task chaining, if the request was successful, CCp handles the request the same as a queued terminal program requesr.
y't/ote.' Once a terminal has a program request queued, the request cannot be removed from the queue except by the system operator. Oueued chain task requests cannot be canceled.
There are five situations where the /O command is effective for program requests:
A d i s k f i l e i s t e m p o r a r i l y n o t a v a i l a b l e b e c a u s e o f f i l e s h a r i n g .
T h e n r a i n s t o r a g e f o r t h e p r o g r a m is n o t a v a i l a b l e . A r e q u i r e d te r m i n a l i s t e m p o r a r i l y in u s e .
A m u l t i p l e r e q u e s t i n g t e r m i n a l ( M R T ) p r o g r a m is a c t i v e a n d a l r e a d y h a s th e m a x i m u m n u m b e r o f r e q u e s t e r s . T h e n r a x i m u m n u m b e r o f p r o g r a m s m i g h t a l r e a d y b e e x e c u t i n q .
F i l e S p e c i f i c a t i o n C o m m a n d ( / F l L E l
T h e f i l e s p e c i f i c a t i o n c o m m a n d s p e c i f i e s w h i c h o f s e v e r a l d a t a f i l e s to u s e o n a c u r r e n t p r o g r a m r u n . T h e t e r m i n a l operator may use the file specification command to vary t h e f i l e s t h a t a r e u s e d b y t h e p r o g r a m s h e r e q u e s t s . T h e f i l e s p e c i f i c a t i o n c o m m a n d c a n n o t b e u s e d w i t h m u l t i o l e requester programs and is not used with a chain task request.
C e r t a i n a p p l i c a t i o n p r o g r a m s a r e w r i t t e n t o a c c e s s a n y o f s e v e r a l f i l e s c o n t a i n i n g s i m i l a r d a t a i n t h e s a m e fo r m a t b y referring to a symbolic file in the program. For the program t o a c t u a l l y a c c e s s a f i l e , t h e n a m e o f t h e s y m b o l i c f i l e m u s t b e a s s o c i a t e d w i t h t h e n a m e o f a f i l e t h a t a c t u a l l y e x i s t s o n disk, a physical file.
Suppose, for example, a school system has a separate stu- dent records file for each school. A student report program can process the student records file from any of the schools, b u t i t m u s t b e t o l d . b y a f i l e s p e c i f i c a t i o n c o m m a n d , w h i c h o f t h e f i l e s t o u s e o n a p a r t i c u l a r ru n ( F i g u r e 2 ) .
S y m b o l i c f i l e n a m e u s e d in t h e p r o g r a m . F i l e s p e c i f i c a t i o n c o m m a n d
s a y s : "F o r t h i s ru n , S C H O O L X i s S C H O O L l . "
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F i g u r e 2 . l l l u s t r a t i o n of File Specif ication Command
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S C H O O L 3
P h y s i c a l f i l e s t o w h i c h t h e s y m b o l i c f i l e n a m e c a n r e f e r .
S C H O O L 2
