ab initio - ACS Publications

11 A Case History in Computer Resource Sharing:

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ab initio Calculations via a Remote Control* D. G. HOPPER,† P. J. FORTUNE, and A. C. WAHL Chemistry Division, Argonne National Laboratory, Argonne, Ill. 60439 T. O. TIERNAN†† Chemistry Research Laboratory, Aerospace Research Laboratories, Air Force Systems Command, Wright-Patterson Air Force Base, Ohio 45433 In this paper we discuss the experience that we have had in performing large scale molecular structure calculations remotely using the CDC6600 computers at Wright-Patterson Air Force Base. Certain elements of this effort are general and can be expected to be encountered by other researchers. Before proceeding with a discussion of this computational research project we w i l l give a brief history of the development of the Wright-Patterson AFB Aeronautical Systems Division (ASD) computer center, which played a historic and central role in the development of modern computational chemistry. Computational chemistry has become a pervasive tool contributing to the solution of problems in the biological, inorganic, organic, and physical subfields of chemistry. And it w i l l undoubtedly become an even more important tool in years to come. Such growth is due to the fact that in many areas of computational chemistry, the methods used yield results which meet experimental accuracy, allowing quantitative prediction and interpretation to be made (1-3). Methods of performing e.g. accurate quantum mechanical calculations are now available in computer codes which can be obtained from code exchanges (3) and from individual research groups. It is proper to refer to these codes and the hardware associated with their application as instruments for chemical research, in the same sense as an *Work performed under the auspices of the USERDA and Air Force Contract No. F33615-72-M-5015. †ARL-NRC Research Associate 1972-1974. ††Present address: Department of Chemistry, Wright State University, Dayton, Ohio 45431.

153 Lykos; Computer Networking and Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 1975.


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e q u a l l y s o p h i s t i c a t e d e x p e r i m e n t a l " a p p a r a t u s " (£) . Remote usage o f t h e s e l a r g e c o m p u t a t i o n a l systems i s becoming i n c r e a s i n g l y more common. The r e a s o n s f o r t h i s i n c r e a s e d remote usage a r e : (a) t r u e p o r t a b i l i t y i s d i f f i c u l t t o a c h i e v e i n a l a r g e s o f t w a r e system, (b) the maintenance, r e l i a b i l i t y , and c o n t i n u i n g d e v e l o p ment o f t h e s e codes r e q u i r e s more e f f o r t and e x p e r t i s e than c a n be m a r s h a l l e d by i n d i v i d u a l c h e m i c a l r e s e a r c h e r s and (c) remote use i s p o s s i b l e , c o n v e n i e n t , and economically competitive with on-site v i s i t s . I ti s r e a s o n a b l e t o e x p e c t t h a t an even more s u b s t a n t i a l p o r t i o n o f c h e m i c a l c a l c u l a t i o n s w i l l be performed remote l y from i n t e r a c t i v e ( t i m e - s h a r i n g ) and b a t c h t e r m i n a l s (.5) , p a r t i c u l a r l y as computer networks (£, Ί_, £, 9) become more w i d e l y a c c e s s i b l e . In t h i s r e p o r t we r e v i e w our s p e c i f i c e x p e r i e n c e w i t h remote i n t e r a c t i v e t e r m i n a l a c c e s s . We d i s c u s s the f e a s i b i l i t y o f p e r f o r m i n g m o d e r a t e l y e x t e n s i v e ab i n i t i o p r o d u c t i o n c a l c u l a t i o n s w i t h no more than a t e l e t y p e a t t h e remote s i t e . The e n t i r e p r o c e d u r e i s s t r a i g h t - f o r w a r d and, a l t h o u g h t e d i o u s , c a n be g r e a t l y f a c i l i t a t e d by a p p r o p r i a t e code m o d i f i c a t i o n s and code developments. The f o l l o w i n g d i s c u s s i o n i s broken down i n t o the s i x s e c t i o n s : nature o f the c a l c u l a t i o n s b e i n g performed, equipment a v a i l a b l e , communication l i n k s , i n s t a l l a t i o n and maintenance o f codes, i n p u t and o u t p u t o f j o b s , and a summary and i n d i c a t i o n o f f u t u r e plans. F o r t h e purpose o f g a i n i n g p e r s p e c t i v e on t h i s e f f o r t we b e g i n by r e v i e w i n g t h e r o l e p l a y e d by t h e ASD Computer C e n t e r a t W r i g h t - P a t t e r s o n AFB i n computer r e s o u r c e s h a r i n g i n quantum c h e m i s t r y c o m p u t a t i o n s . H i s t o r y o f Computer Resource A i r F o r c e Base

Sharing a t Wright-Patterson

The h i s t o r i c a l e v o l u t i o n o f o u r remote usage has p a r a l l e l e d t h e development o f t h e computer c e n t e r a t W r i g h t - P a t t e r s o n A i r F o r c e Base. I t was t h e s h a r i n g o f computer r e s o u r c e s by W r i g h t - P a t t e r s o n i n t h e l a t e 1950's t h a t e n a b l e d one o f t h e f i r s t i n t e g r a l programs t o be d e v e l o p e d and r u n . T h i s e v o l u t i o n i n t h e use o f the W r i g h t - P a t t e r s o n c o m p u t a t i o n a l f a c i l i t y by o f f - s i t e p e r s o n n e l , a c c o m p l i s h e d e n t i r e l y by s i t e v i s i t s i n about 1958, t o t h e p r e s e n t s t a g e o f e x t e n s i v e remote o p e r a t i o n s p r o v i d e s , t h e r e f o r e , a v i v i d example o f com p u t e r r e s o u r c e a v a i l a b i l i t y and s h a r i n g . T h i s example i s i l l u s t r a t i v e o f a r e s e a r c h a r e a — c o m p u t a t i o n a l chem i s t r y — w h i c h w i l l be markedly advanced by t h e d e v e l o p ment o f computer networks.

Lykos; Computer Networking and Chemistry ACS Symposium Series; American Chemical Society: Washington, DC, 1975.


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Background on t h e ASP Computer C e n t e r . There has been a computer o r g a n i z a t i o n as a p a r t o f t h e W r i g h t P a t t e r s o n A r e a Β l a b o r a t o r y complex s i n c e 1949 (10). A t t h a t time the C o m p u t a t i o n a l Branch o f t h e Research D i v i s i o n , O f f i c e o f A i r Research, was e s t a b l i s h e d . T h i s group began w i t h an e a r l y v i n t a g e MIT a n a l o g computer which was soon r e p l a c e d w i t h t h e f i r s t c o m m e r c i a l l y a v a i l a b l e a n a l o g computer, t h e REAC S e r i e s 100. The d i g i t a l e f f o r t began i n 1951 w i t h t h e d e l i v e r y o f an IBM C a r d Programmed C a l c u l a t o r . To p u t t h e s e e v e n t s i n p e r s p e c t i v e , the d i g i t a l computer was i n v e n t e d by H a r o l d A i k e n o n l y i n 1944; the a n a l o g computer, by Vannevar Bush i n 1930 (11). The f i r s t r e a l s t o r e d program d i g i t a l computer was the OARAC ( O f f i c e o f A i r R e s e a r c h A u t o m a t i c Computer) i n s t a l l e d i n 1953. T h i s computer was a " o n e - o f - a - k i n d " b u i l t s p e c i f i c a l l y by G e n e r a l E l e c t r i c f o r t h e A e r o n a u t i c a l Systems D i v i s i o n . I t was v e r y slow, had l i m i t e d I/O c a p a b i l i t y , and was u n r e l i a b l e . In 1956 i t was r e p l a c e d by a s c i e n t i f i c a l l y - o r i e n t e d U n i v a c 1103. I n 1957 t h e 1103 was upgraded t o an 1103A and assembly language programming became a v a i l a b l e . It i s t h i s computer t h a t p l a y e d an i m p o r t a n t r o l l , as d e s c r i b e d i n t h e n e x t s e c t i o n , i n the development o f ab i n i t i o quantum c h e m i s t r y . The f i r s t e x t e n s i v e use o f a s o u r c e language d i d n ' t o c c u r u n t i l 1961 when the 1103A was r e p l a c e d by an IBM 7090 which a l l o w e d programming i n FORTRAN I I . Open shop was formed a t about t h i s t i m e . The IBM 7090 was t h e f i r s t r e a l b a t c h computer a t ASD; i t used two IBM 1401 computers f o r c o n v e r t i n g c a r d s t o tape i n p u t f o r the 7090 and 7090 tape o u t p u t t o punch and p r i n t e d form. In 1963 the 7090 was upgraded t o a 7094 and t h e n r e p l a c e d i n l a t e 1964 by an IBM 7044/7094 Mod ΓΙ D i r e c t 7044 t o m o n i t o r I/O, j o b f l o w , and d i s k s t o r a g e a l l o c a t i o n f o r the 7094 program e x e c u t i o n . T h i s system had one IBM 1440 remote b a t c h t e r m i n a l i n the Aero P r o p u l sion Laboratory. In 1966 a second, somewhat slower IBM 7040/7090 D i r e c t Coupled System was added; i t had a remote b a t c h t e r m i n a l i n the F l i g h t Dynamics L a b o r a t o r y . Both D i r e c t Coupled systems were r e p l a c e d by a CDC6600 w i t h 31 t e l e t y p e s and 9 remote b a t c h t e r m i n a l s i n January 1971. In December 1973 a CDC CYBER73 was i n s t a l l e d w i t h t h e b a t c h t e r m i n a l s r e a l l o c a t e d among the two systems. * The t e l e t y p e t e r m i n a l s (HOB) were c o n v e r t e d t o o p e r a t e t h r o u g h a d i a l - u p system i n March 1973 and some 300B l i n e s were s i m u l t a n e o u s l y added. There a r e now 32 110/300B l i n e s i n t o each system, t h e CDC6600 and t h e CYBER73. One l i n e o p e r a t i n g a t 2 K/B was added i n •Notation —

Β = Baud

= b i t - p e r - s e c o n d . 1K/B

= 1000B.


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A p r i l 1974 and a second o p e r a t i n g a t 4.8 K/B, i n F e b r u ary 1975. The ASD Computer C e n t e r became a node on the ARPA network (ARPANET) i n October 1973 w i t h t h e i n s t a l l a t i o n of a t e r m i n a l i n t e r f a c e processor (TIP). F u t u r e developments p l a n n e d f o r t h e ASD and o t h e r A i r F o r c e System Command computer c e n t e r s w i l l be d i s c u s s e d below. F o r now we t u r n t o a d i s c u s s i o n o f the r o l e p l a y e d by t h e 1103 and 1103A i n the e v o l u t i o n o f quantum c h e m i s t r y . Development o f Master I n t e g r a l s and SCF Codes. D u r i n g the p e r i o d 1955-1962 the master SCF m o l e c u l e program was d e v e l o p e d f o r l i n e a r systems by the L a b o r a t o r y o f M o l e c u l a r S t r u c t u r e and S p e c t r a o f t h e U n i v e r s i t y o f C h i c a g o as a p a r t o f i t s o v e r a l l e f f o r t i n m o l e c u l a r computations (12,13). The m o l e c u l a r i n t e g r a l s package was d e v e l o p e d and r u n on the U n i v a c 1103 and 1103A a t W r i g h t - P a t t e r s o n A i r F o r c e Base under a con t r a c t w i t h the U n i v e r s i t y . The SCF package was combined w i t h the STO i n t e g r a l package t o form the f i r s t master i n t e g r a l s - S C F code. I t was i n t h i s p e r i o d o f c a l c u l a t i o n s on the 1103 and 1103A t h a t many o f t h e f i r s t m o l e c u l a r H a r t r e e - F o c k c a l c u l a t i o n s w i t h good b a s i s s e t s were c a r r i e d o u t by McLean, Weiss, and Yoshimine (14), K o l o s and Roothaan (15,16), R a n s i l (12,13), and R i c h a r d s o n (Γ7) , e t c . Indeed one f i n d s t h a t the A p r i l 1960 i s s u e o f Reviews o f Modern P h y s i c s — a c o l l e c t i o n of p a p e r s g i v e n a t t h e C o n f e r e n c e on M o l e c u l a r Quantum Mechanics h e l d a t B o u l d e r , C o l o r a d o June 21-27, 1959 — c o n t a i n s no fewer than t w e l v e p a p e r s t h a t acknowledge the use o f t h e 1103 a t the then Wright A i r Development C e n t e r a t W r i g h t - P a t t e r s o n AFB (12-23). These p a p e r s i n c l u d e c o n t r i b u t i o n s by K o l o s , Roothaan, and Sach (18) on t h e ground s t a t e o f H3, Roothaan (19) i n h i s c l a s s i c work on t h e t h e o r y o f open s h e l l s o f e l e c t r o n i c systems, K o l o s and Roothaan {20) on c o r r e l a t e d o r b i t a l s f o r He, F r a g a and M u l l i k e n (21) on t h e r o l e o f Coulomb energy i n v a l e n c e bond t h e o r y , Frôman (22) on r e l a t i v i s t i c c o r r e c t i o n s , and Lowdin (23) on e x p a n s i o n t h e orems f o r t h e t o t a l w a v e f u n c t i o n and extended H a r t r e e Fock schemes. Many o t h e r i n d i v i d u a l s p a r t i c i p a t e d i n this c a l c u l a t i v e e f f o r t at Wright-Patterson—Bagus, C l e m e n t i , Ehrenson, Huo, Lykos, M a l l i , P h i l l i p s o n , and Wahl t o mention a few. S. Huzinaga w r i t e s i n a l e t t e r to Dr. R. Euwema o f the t h e o r e t i c a l s o l i d - s t a t e group a t W r i g h t - P a t t e r s o n d a t e d F e b r u a r y 7, 1975: "WrightP a t t e r s o n i s one o f my f o n d e s t memories d u r i n g my s t a y i n U.S.A. some 15 y e a r s ago. I had a c c e s s t o a b i g computer (UNIVAC 1103?) f o r t h e f i r s t time i n my l i f e . "


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The 1103 and 1103A p r o v i d e d a c o m p u t a t i o n a l t e s t ground f o r many i d e a s i n t h e o r e t i c a l c h e m i s t r y and a p l a c e where the seeds o f f u t u r e developments i n the I 9 6 0 s were sowed. I t was h e r e , f o r example, where newer i d e a s on how t o code d i a t o m i c i n t e g r a l s were e v a l u a t e d and the o n e - e l e c t r o n i n t e g r a l s coded and t e s t e d (24). The c h o r e s o f c o d i n g and e x e c u t i o n o f computations on the 1103A were markedly d i f f e r e n t from the p r e s e n t day h i g h - l e v e l language and b a t c h j o b i n p u t o p e r a t i o n s , as one o f us (A.C.W.) v i v i d l y r e c a l l s . Coding was p e r formed d i r e c t l y i n o c t a l machine language, t o o p t i m i z e the use o f computer memory. A c c u r a t e f l o a t i n g - p o i n t operations required a user-supplied subroutine. Job s u b m i s s i o n was an e x t r a o r d i n a r y e x e r c i s e i n p r e p a r a t i o n and p a t i e n c e . The computer r e s i d e d on a l o v e l y , b l u e l i t d i a s and the u s e r w a i t e d i n a "ready room" u n t i l h i s name was c a l l e d . He would t h e n r u s h i n w i t h h i s paper t a p e s f o r a 2-3 minute s h o t a t g e t t i n g h i s j o b on the machine. I f he f a i l e d t o g e t i t g o i n g i n t h a t l e n g t h o f time he l o s t h i s t u r n and had t o go t o the end o f the queue. A n o t h e r t u r n would come i n two hours t o two days, depending upon demand. The use o f the 1103 and 1103A by the C h i c a g o group was a m i l e s t o n e i n the e a r l y s h a r i n g o f computer r e sources. In t h i s case c o m p u t a t i o n a l c h e m i s t s o b t a i n e d a c c e s s t o a s u f f i c i e n t l y p o w e r f u l computer f o r t h e i r purposes - a computer u n a v a i l a b l e t o them i n C h i c a g o by making s i t e v i s i t s t o W r i g h t - P a t t e r s o n .


1

Ab I n i t i o Quantum C a l c u l a t i o n s from 1961-1975 a t W r i g h t - P a t t e r s o n AFB. D u r i n g the p e r i o d 1961-1972 the ab i n i t i o work i n quantum c h e m i s t r y a t W r i g h t - P a t t e r s o n AFB was much more l i m i t e d than the 1956-1961 p e r i o d . The r e a s o n was the a v a i l a b i l i t y o f e q u i v a l e n t o r b e t t e r computers a t o r v e r y near the i n s t i t u t i o n s i n C h i c a g o and elsewhere a t which t h e quantum c h e m i s t s r e s i d e d . However, d u r i n g much o f t h i s p e r i o d and c o n t i n u i n g on u n t i l 1975 t h e r e has been a s t r o n g t h e o r e t i c a l s o l i d s t a t e group a t the A e r o s p a c e Research L a b o r a t o r i e s . T h i s group has been d e v e l o p i n g methods and v e r y h i g h l y s o p h i s t i c a t e d codes f o r p e r f o r m i n g r i g o r o u s ab i n i t i o H a r t r e e - F o c k c a l c u l a t i o n s o v e r the y e a r s on the IBM 7094 and, c u r r e n t l y , the CDC6600. The p e r i o d 1972-1975 saw an upsurge i n ab i n i t i o quantum c h e m i c a l c a l c u l a t i o n s . A few group l e a d e r s i n the C h e m i s t r y R e s e a r c h L a b o r a t o r y o f the A e r o s p a c e Research L a b o r a t o r i e s brought i n t h e o r e t i c a l p e r s o n n e l on a temporary b a s i s t o e x e c u t e c o m p u t a t i o n a l r e s e a r c h p r o j e c t s r e l a t e d t o on-going, in-house e x p e r i m e n t a l


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programs. The Aerospace R e s e a r c h L a b o r a t o r i e s , t h r o u g h a program i n i t i a t e d by one o f t h e p r e s e n t a u t h o r s (T.O. T.), a l s o c o n t r a c t e d out-of-house t h e o r e t i c a l c a l c u l a t i o n s r e l e v a n t to A i r Force i n t e r e s t s . One such cont r a c t i n v o l v e d t h e c o m p u t a t i o n a l c h e m i s t r y groups a t Argonne N a t i o n a l L a b o r a t o r y and the N a t i o n a l Bureau o f Standards who undertook a c o n c e r t e d l i t e r a t u r e e v a l u a t i o n and i n i t i a t e d a s t a t e - o f - t h e - a r t c o m p u t a t i o n a l p r o j e c t t o o b t a i n i n f o r m a t i o n on the v e r t i c a l e x c i t a t i o n s p e c t r a and p o t e n t i a l energy h y p e r s u r f a c e s o f t h e e l e c t r o n i c s t a t e s o f t h e f i f t e e n m o l e c u l e s and i o n s H 0 , N20* , C 0 , N0 , 0 , m = +1, 0, -1 (24-31). The work r e p o r t e d i n t h i s paper i s a development o f t h a t computational p r o j e c t . I t i s i n the context of t h i s program t h a t we w i l l d i s c u s s remote usage. m

1

m

m

m


2

Nature

o f P r o j e c t and C a l c u l a t i o n s B e i n g

Performed.

F o r about t h r e e y e a r s our r e s e a r c h groups, i n conc e r t w i t h those o f M. Krauss a t t h e N a t i o n a l Bureau o f Standards (NBS) and J . Simons a t the U n i v e r s i t y o f Utah (Utah) have c o o p e r a t e d i n c o m p u t a t i o n a l c h e m i s t r y p r o jects. In t h e s e j o i n t i n v e s t i g a t i o n s the group a t the Aerospace Research L a b o r a t o r i e s (ARL) c o l l a b o r a t e d i n the development o f o b j e c t i v e s , m o n i t o r e d p r o g r e s s , and p r o v i d e d computer r e s o u r c e s . The group ab Argonne N a t i o n a l L a b o r a t o r y (ANL) c o n s t r u c t e d CDC6600 v e r s i o n s o f i t s BISON, BISONMC, DASCI, and POLYINT codes and made them o p e r a t i v e a t W r i g h t - P a t t e r s o n AFB (24-28). The group at t h e U n i v e r s i t y o f Utah implemented codes f o r i t s e q u a t i o n s - o f - m o t i o n method f o r computing i o n i z a t i o n p o t e n t i a l s and e l e c t r o n a f f i n i t i e s from SCF wavefunct i o n s (32). Our remote i n t e r a c t i v e t e r m i n a l set-up i s d e p i c t e d s c h e m a t i c a l l y i n F i g u r e 1. These r e s e a r c h groups then proceeded t o pursue program o b j e c t i v e s u t i l i z i n g t h e s e common r e s o u r c e s . The ARL-ANL-NBS p r o j e c t i s d e s i g n e d t o c a t a l o g what i s p r e s e n t l y known from b o t h t h e o r y and experiment about the dominant a t m o s p h e r i c m o l e c u l e s H2O, N0 / CO2, O3, N 0 and t h e i r p o s i t i v e and n e g a t i v e i o n s , t o c r i t i c a l l y r e v i e w t h i s i n f o r m a t i o n , and t o supplement t h a t information i n a systematic computational f a s h i o n with theoretical calculations. T h i s new t h e o r e t i c a l knowl e d g e can then be used t o advance the e x p e r i m e n t a l •* T h i s s e t o f codes p r o v i d e s f o r the ab i n i t i o computat i o n o f p o l y a t o m i c w a v e f u n c t i o n s , p r o p e r t i e s , and potent i a l s u r f a c e s by t h e o p t i m i z e d v a l e n c e c o n f i g u r a t i o n s (OVC) multiconfiguration self-consistent-field (MCSCF) c o n f i g u r a t i o n - i n t e r a c t i o n (CI) t e c h n i q u e . 2

2


11.

HOPPER E T

AL.

Calculations

via

Remote

159

Terminal

a n a l y s i s by p a r t i c i p a t i n g i n a feedback p r o c e s s which h i s t o r i c a l l y has proven t o be i m p o r t a n t i n u n d e r s t a n d i n g the phenomena i n v o l v e d . A c r i t i c a l review of the l i t e r a t u r e has been completed i n which e x t e n s i v e use i s made of s t a t e a d i a b a t i c c o r r e l a t i o n diagrams t o summarize p o t e n t i a l energy s u r f a c e c h a r a c t e r i s t i c s (33). The v e r t i c a l s p e c t r a o f the above f i f t e e n m o l e c u l e s and m o l e c u l a r i o n s have been computed a t the SCF l e v e l and, f o r some, a t the OVC-MCSCF-CI* l e v e l (34). Potential surf-aces f o r v a r i o u s s t a t e s o f Η 2 θ , H2O, N2O"", Ν 2 θ , Ν 0 ~ and NO2 have a l s o been examined (34) . F u r t h e r s t u d i e s w i t h t h e OVC-MCSCF-CI t e c h n i q u e a r e c u r r e n t l y underway. +

1


2

Terminal

Equipment

In the e a r l y s t a g e s o f t h i s p r o j e c t a l l a c t i v i t y proceeded by s i t e v i s i t s t o W r i g h t - P a t t e r s o n A i r F o r c e Base (WPAFB). A f t e r about one y e a r , d i a l - u p i n t e r a c t i v e t e r m i n a l c o n n e c t i o n s became a v a i l a b l e a t WPAFB and we were a b l e t o p e r f o r m much o f the maintenance and produc t i o n work r e m o t e l y from 110R and, somewhat l a t e r , from 300B i n t e r a c t i v e t e r m i n a l s . Most o f our e f f o r t was w i t h s i m p l e HOB t e l e t y p e s l o c a t e d a t ANL, NBS, Utah, and WPAFB. A 30OB CRT t e r m i n a l was a v a i l a b l e f o r code maintenance o n - s i t e a t W r i g h t - P a t t e r s o n on the same d i a l - u p b a s i s as the HOB and 300B o f f - s i t e t e r m i n a l s . The r e q u i r e m e n t s imposed upon the c h o i c e o f a r e mote t e r m i n a l and upon the t a c t i c s o f o p e r a t i o n i n an e f f o r t such as o u r s are e s s e n t i a l l y t h o s e o f any l a r g e s c i e n t i f i c c o m p u t a t i o n a l p r o j e c t . One needs the c a p a c i t y t o f o r m u l a t e and t r a n s m i t numerous p r o d u c t i o n j o b s t o the h o s t computer b a t c h i n p u t queue and t o r e c e i v e and examine o u t p u t . I t i s then n e c e s s a r y t o be a b l e t o m a n i p u l a t e f i l e s on the h o s t computer v i a some s o r t o f an i n t e r a c t i v e o p t i o n (e.g. CDC INTERCOM, IBM TSO). However, t h e r e a r e some c h a r a c t e r i s t i c s o f ab i n i t i o quantum c h e m i c a l c a l c u l a t i o n s which r e q u i r e s p e c i a l attention. W h i l e i t might be p o s s i b l e , f o r i n s t a n c e , f o r us t o e s t a b l i s h p r o d u c t i o n l o a d modules p e r i o d i c a l l y , i t i s n e c e s s a r y t o m a i n t a i n and c o n t i n u a l l y upgrade each o f f i v e , 4000-7000 c a r d , s o u r c e codes r e s i d e n t on the h o s t computer. A CRT t e r m i n a l component and a means o f o b t a i n i n g updated line-numbered, 80-80 s o u r c e l i s t i n g s worked w e l l f o r us. T h i s p r o c e d u r e r e q u i r e d ons i t e personnel. Some m o d i f i c a t i o n s were a c c o m p l i s h e d * See

footnote

on p r e v i o u s

page.



160

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c o m p l e t e l y r e m o t e l y w i t h a t e l e t y p e from e i t h e r Argonne or Utah. Furthermore, t h e i n p u t decks f o r p r o d u c t i o n runs a r e q u i t e l a r g e (200-400 c a r d s ) and o f t e n change v e r y s u b s t a n t i a l l y from one r u n t o t h e n e x t . For t h i s reason i t i s not expedient t o c o n s t r u c t these input decks s o l e l y v i a t h e keyboard. I n s t e a d , we found i t u s e f u l t o m a i n t a i n a l i b r a r y o f model i n p u t decks on the h o s t computer mass s t o r a g e media o r on remote s i t e media such as paper tape o r magnetic tape c a s s e t t e s . A model i n p u t deck c a n c o n s i s t o f t h e "punched" o u t p u t from a p r e v i o u s r u n and may be s t o r e d w i t h t h e j o b cont r o l cards attendent t o i t s execution i n p l a c e . Input decks on t h e above-mentioned remote s i t e media c a n be c o n s t r u c t e d l o c a l l y from punched c a r d s i f a b a t c h computer f a c i l i t y i s a v a i l a b l e . The t e x t e d i t o r o f t h e i n t e r a c t i v e s o f t w a r e system o f t h e h o s t computer c a n then be used t o c o n s t r u c t t h e d e s i r e d i n p u t deck from these sources. Another c h a r a c t e r i s t i c o f t h e type o f c a l c u l a t i o n s w i t h which we a r e c o n c e r n e d i s t h e l a r g e s i z e o f t h e output f i l e s . F o r such f i l e s as t h e s e — f i l e s o f t e n i n e x c e s s o f 4000 l i n e s — complete p r i n t i n g a t a r e mote i n t e r a c t i v e t e r m i n a l o p e r a t i n g a t 110-1200B i s n o t practical. Even a remote b a t c h t e r m i n a l o p e r a t i n g a t 2000-4800B would r e q u i r e p r o h i b i t i v e t r a n s m i s s i o n times. To remedy t h i s problem we have m o d i f i e d o u r codes t o produce p r i n t e d o u t p u t f i l e s i n a summary, as w e l l as the d e t a i l e d s t a n d a r d , form. For production c a l c u l a t i o n s w i t h o u r BISONMC code some 100 70-column l i n e s s u f f i c e t o c o n t a i n the important i n f o r m a t i o n . A t e l e type has s e r v e d , i n o u r p r o j e c t , t o e n a b l e t h e p r o d u c t i o n o f such p r i n t e d summaries a t each remote s i t e . The s t a n d a r d o u t p u t f i l e s were p r i n t e d a t t h e h o s t comp u t e r and m a i l e d t o t h e r e s p e c t i v e u s e r as needed. T a b l e I i s a comparative d i s p l a y o f t h e c h a r a c t e r i s t i c s o f t h e i n t e r a c t i v e t e r m i n a l s we have used r e m o t e l y — u n i t s 1 and 2 — and would l i k e t o — unit 3. Some d e s i r a b l e b a t c h t e r m i n a l c h a r a c t e r i s t i c s a r e i n c l u d e d i n T a b l e I f o r completeness; d i s c u s s i o n o f these i s d e f e r r e d t o a l a t e r s e c t i o n . F o r o u r type o f a p p l i c a t i o n , o p t i o n s such as d i s k packs, p l o t t e r s , and tape d r i v e s , w h i l e c o s t l y t o a c q u i r e and m a i n t a i n , p r o v i d e no s e r v i c e n o t a l r e a d y a v a i l a b l e v i a t h e h o s t computer. F o r t h i s r e a s o n t h e y have been o m i t t e d from T a b l e I . Of c o u r s e , i f some o f t h e s e components a r e a l r e a d y a v a i l a b l e , t h e y c a n be used t o advantage. AISQ a remote s i t e t e x t e d i t i n g c a p a b i l i t y c a n be h e l p f u l t o our t y p e o f a p p l i c a t i o n . Examples o f t h e l a t t e r i n c l u d e a d u a l tape c a s s e t t e u n i t and t h e i n t e r a c t i v e s o f t w a r e o f a computer l o c a l t o t h e remote s i t e .


11.

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Calculations

via Remote

Terminal

161

U n i t 1, t h e t e l e t y p e o r e q u i v a l e n t d e v i c e , i s p r o m i n e n t l y numbered i n T a b l e I t o s t r e s s t h e f a c t s (a) t h a t i t i s i n our experience capable o f e n a b l i n g , a t m i n i m a l c o s t , a modest r a t e o f p r o d u c t i o n c o m p u t a t i o n and (b) t h a t i t i s a l r e a d y w i d e l y a v a i l a b l e . F o r i n d i v i d u a l s e v a l u a t i n g equipment f o r a remote t e r m i n a l ( i n t e r a c t i v e o r batch) we note t h a t a v e r y d e t a i l e d compendium o f i n f o r m a t i o n about t e r m i n a l s , modems, d a t a communications, e t c . i s a v a i l a b l e (35.) as w e l l as o t h e r background i n f o r m a t i o n (_36) .


Communication L i n k s . The most common communication l i n k between remote t e r m i n a l s and computers i s a phone l i n e . While the s i m p l e s t and an o f t e n r e l i a b l e way t o use a phone l i n e i s t o d i r e c t - d i a l o v e r t h e p u b l i c network, t h i s i s n o t always p o s s i b l e . Thus, i t i s o f t e n n e c e s s a r y t o go t h r o u g h e x t r a l a y e r s o f e f f o r t on each c a l l — i . e . i n s t i t u t i o n a l exchanges — and t o p u t up w i t h t h e n o i s y l i n e s o f p r i v a t e phone networks. The h i g h e r t r a n s m i s s i o n f a i l u r e r a t e s on n o i s y l i n e s c a n l i m i t an i n t e r a c t i v e t e r m i n a l / h o s t computer c o m b i n a t i o n c a p a b l e o f 1200B o r 300B t o H O B . Regular voice-grade p u b l i c t e l e p h o n e l i n e s a r e c a p a b l e o f t r a n s m i s s i o n r a t e s up t o 4800B ( 3 5 ) . P u t a n o t h e r way, t h e u n d e t e c t e d e r r o r r a t e on p u b l i c l i n e s i s one i n Ι Ο ^ - Ι Ο b i t s a t most, g i v e n the c u r r e n t t e c h n o l o g y f o r s i g n a l t r a n s m i s s i o n o v e r an audio w i r e . Leased l i n e s a r e much more e x p e n s i v e b u t can s u p p o r t up t o 9600B (3j>) . I n t e r a c t i v e t e r m i n a l s and h o s t computers a r e commonly c a p a b l e o f s u p p o r t i n g 110, 300, and 1200B o p e r a t i o n . Remote b a t c h t e r m i n a l s and h o s t computers a r e commonly c a p a b l e o f s u p p o r t i n g 2000 and 4800B o p e r a t i o n . However, i t i s c l e a r t h a t one s h o u l d n o t p u r c h a s e a t e r m i n a l and modem c a p a b l e o f more than 110 o r 300B i f i t i s n o t p o s s i b l e t o e s t a b l i s h t h a t t h e r e m o t e - t o - h o s t phone c o n n e c t i o n c a n support the higher t r a n s m i s s i o n r a t e . When o u r p r o j e c t began we were l i m i t e d t o 110B t r a n s m i s s i o n by our i n t e r a c t i v e t e r m i n a l — a Model 33 T e l e t y p e — and we employed d i r e c t - d i a l i n g o f t h e W r i g h t - P a t t e r s o n AFB computer from Argonne. L a t e r we upgraded o u r i n t e r a c t i v e t e r m i n a l c a p a c i t y t o 300B b u t were s t i l l l i m i t e d t o H O B by a r e q u i r e m e n t t h a t we employ FTS l i n e s , which we found t o be r a t h e r n o i s y . T h i s problem was compounded by t h e f a c t t h a t FTS c a l l s t o t h e computer a t W r i g h t - P a t t e r s o n had t o go t h r o u g h the base s w i t c h b o a r d and were, t h e r e f o r e , l i m i t e d t o about f i v e minutes d u r i n g b u s i n e s s h o u r s . Future s o l u t i o n s t o t h e communication l i n k problem ( c o s t and 7


162

COMPUTER

Table I.

Unit


1

2

3

4

NETWORKING

Renote Terminal Choices for Computational

Baud Rate Cap.

110

110 300 1200

110 300 1200 2400 4800

2000 4800 9600

Equipment

AND CHEMISTRY

Chemistry.

0

Type In

Usage Stor. Out

Cost

^$

teletype keyboard 70 c o l . printer (impact) paper tape

-

X

-

X

X

X

X

X

electronic keyboard 80 c o l . printer (thermal) dual tape cassettes electronic keyboard 132 c o l . printer dual tape cassettes card reader card punch CRT batch terminal keyboard 132 char, printer card reacher card punch

900

^$ 3600

-

X

-

X

X

X

X

X

^$ 9000

X

-

X X

-

X

X

-

X —

X

-

X

X

X

-

X

X X

-

-

-

^$30000

-

X

X

X

X

Obtention of an appropriate modem i s assumed (35). t r a n s m i s s i o n r a t e ) and a l t e r n a t i v e s t o phone l i n e s w i l l be d i s c u s s e d below. From our e x p e r i e n c e on communicat i o n l i n k s the phone c o n n e c t i o n i s the major d i f f i c u l t y o f remote d a t a p r o c e s s i n g .

* I n s t a l l a t i o n and Maintenance

o f Codes

In our work t h e computer programs (codes)^have been i n s t a l l e d o n l y by s i t e v i s i t s . Maintenance of Maintenance o f codes i s , i n the p r e s e n t c o n t e x t , t a k e n t o i n c l u d e n o t o n l y t h e maintenance o f o p e r a t i v e l o a d modules and s o u r c e decks on the h o s t computer p u b l i c d i s k and tape l i b r a r i e s , b u t a l s o t h e u p d a t i n g o f codes t o accomodate changes i n the o p e r a t i n g system, t o improve performance, and t o i n c o r p o r a t e new f e a t u r e s .


11.

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AL.

Calculations

via

Remote

Terminal

163


the f o u r ANL codes ( 2 4 - 2 7 ) was a l s o performed o n - s i t e f o r the most p a r t , m a i n l y by the use o f a CRT i n t e r active terminal. The l a t t e r was g r e a t l y f a c i l i t a t e d by the g e n e r a t i o n o f an updated s o u r c e l i s t i n g , l i n e numb e r e d i n the same s t y l e as i n the e d i t f i l e , a f t e r each code m o d i f i c a t i o n s e s s i o n a t the t e r m i n a l . However, a s i g n i f i c a n t p o r t i o n o f the code maintenance was performed v i a t e l e t y p e from e i t h e r Argonne o r Utah. I t was v e r y h e l p f u l , t h e r e f o r e , t o keep a c u r r e n t and d e t a i l e d s e t o f manuals f o r the h o s t comp u t e r a t each remote s i t e (Argonne and Utah) from which code maintenance a c t i v i t y was u n d e r t a k e n . Input and

Output

Job I n p u t . The t r a d i t i o n a l way o f j o b i n p u t i s by p h y s i c a l c a r d decks v i a a c a r d r e a d e r . A cardr e a d e r can be o b t a i n e d as an add-on o p t i o n t o many i n t e r a c t i v e t e r m i n a l s on the market and i s a s t a n d a r d component o f b a t c h t e r m i n a l s . However, as d i s c u s s e d e a r l i e r a c a r d r e a d e r i s not i n d i s p e n s i b l e t o an i n t e r active terminal operation. The power o f the h o s t comp u t e r i n t e r a c t i v e s o f t w a r e (e.g. INTERCOM on CDC and TSO on IBM machines) can be b r o u g h t t o bear on j o b a s sembly; and d u a l tape c a s s e t t e s can make i t p o s s i b l e t o p e r f o r m many o f the same j o b c o n s t r u c t i o n t a s k s o f f line. I t i s h e l p f u l t o m o d i f y codes t o a c c e p t f o r m a t f r e e i n p u t as o u r s have been ( 2 4 - 2 7 ) . In a d d i t i o n , s m a l l programs f o r , (a) d a t a s e t c o n s t r u c t i o n - b y i n t e r a c t i v e - t e r m i n a l - i n t e r v i e w , and (b) d a t a s e t v e r i f i c a t i o n , are q u i t e u s e f u l . We have w r i t t e n such s m a l l , r a p i d t u r n - a r o u n d programs f o r use i n c o n j u n c t i o n w i t h our BISON and BISONMC codes (24,2J5) . Such u s e r s o f t ware m o d i f i c a t i o n , development, and u t i l i z a t i o n measures make i t p o s s i b l e t o o p e r a t e e f f i c i e n t l y w i t h o u t p h y s i c a l card decks. In the p r e s e n t l y r e p o r t e d work j o b s were e s t a b l i s h e d i n the e d i t f i l e under the EDITOR mode o f CDC INTERCOM and t h e n saved and b a t c h e d i n t o the i n p u t queue. The e d i t f i l e was e s t a b l i s h e d by (a) k e y - i n , (b) r e a d - i n o f a paper t a p e , o r (c) l o a d - i n o f a f i l e s t o r e d on a h o s t computer d i s k , f o l l o w e d by a p p r o p r i a t e modifications. A t Argonne, a u t i l i t y program was w r i t t e n t o run on the C h e m i s t r y D i v i s i o n SIGMA 5 computer t o c o n v e r t a punched-card i n p u t deck f o r the CDC6600 i n t o a paper t a p e . T h i s paper tape was then r e a d i n o v e r the t e l e t y p e . Back-up o f i n p u t j o b s was on paper tape o r h o s t d i s k f i l e .



164

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NETWORKING

AND

CHEMISTRY

Output — G e n e r a l Comments. Output f i l e s a r e generated f o r s e v e r a l reasons: the p e r u s u a l of r e s u l t s from a r u n , t h e c o n s t r u c t i o n o f i n p u t d e c k s , and t h e archiving of r e s u l t s . As w i t h t h e i n p u t o f j o b s , o u t p u t has t r a d i t i o n a l l y been h a r d copy — print-outs and punched c a r d d e c k s . Again, both of these are usuall y a v a i l a b l e from a b a t c h t e r m i n a l . A l t e r n a t i v e l y , one can t a k e advantage o f the h o s t computer i n t e r a c t i v e s o f t w a r e and c o d i n g i n n o v a t i o n s t o handle t h e n e c e s s a r y o u t p u t m a n i p u l a t i o n s from an i n t e r a c t i v e t e r m i n a l . T h i s i s e s p e c i a l l y advantageous f o r l o n g p r i n t - f i l e s , f o r l a r g e numbers o f p r i n t f i l e s , and f o r punch f i l e s . Any p o r t i o n o f a f i l e can be l i s t e d a t w i l l , so t h a t t h e r e i s l e s s need t o p r i n t f u l l o u t p u t f i l e s . An o u t p u t m a i l - b a c k p r o c e d u r e must s t i l l be m a i n t a i n e d , however, f o r t h o s e c a s e s where a l e n g t h y p r i n t - o u t (on paper o r m i c r o f i c h e ) o r r e a l punched o u t p u t i s n e c e s s a r y . The p e r u s a l f u n c t i o n can be s a t i s f a c t o r i l y performed w i t h a CRT o u t p u t d i s p l a y o r a low-speed p r i n t e r . The a r c h i v a l f u n c t i o n r e q u i r e s some type o f s t o r a g e d e v i c e on the h o s t computer o r a t the remote s i t e . File s t o r a g e and m a n i p u l a t i o n a r e d i s c u s s e d under o t h e r subheadings. In our c a s e a l l remote o u t p u t has been by t e l e t y p e or t e l e t y p e - l i k e d e v i c e s . I t was n e c e s s a r y t o s t o r e the punch f i l e as a c a t a l o g u e d d i s k o r magnetic tape f i l e d u r i n g e x e c u t i o n o f a r e m o t e - e n t r y j o b on the WPAFB CDC6600; o t h e r w i s e i t was l o s t t o t h e remote u s e r . A l s o , o u t p u t p r i n t and punch f i l e s had t o be backed up on h o s t computer tape b e f o r e r u n t e r m i n a t i o n i f we were t o a v o i d s u f f e r i n g from the o c c a s i o n a l l o s s of u n a r c h i v e d and o f temporary d i s k f i l e s . We p r o t e c ted o u r s e l v e s from l o s i n g a r u n c o m p l e t e l y , due t o , (a) abnormal program t e r m i n a t i o n o r (b) an o p e r a t o r drop (e.g. "SORRY — MUST DROP TO RUN CLASSIFIED") by making the punched as w e l l as the p r i n t e d o u t p u t summary f i l e dynamic i n t h a t i t was updated a f t e r each i t e r a t i o n t o the l a t e s t o r b i t a l s , e n e r g i e s , and configuration coefficients. Output — 70 C h a r a c t e r / L i n e O p t i o n . Because n a r row c a r r i a g e p r i n t e r s and CRT s c r e e n s a r e so common f o r i n t e r a c t i v e t e r m i n a l s , we have m o d i f i e d our codes POLYINT, BISONMC, and DASCI t o p r o v i d e an o p t i o n by which the u s e r may s p e c i f y t h a t a l l p r i n t e d o u t p u t f i l e s be i n a 70 c h a r a c t e r / l i n e format. These We chose 70 c h a r a c t e r s / l i n e because we found i t t o be the maximum s u i t a b l e f o r a model 35 t t y .


Calculations

HOPPER E T A L .

via Remote

Terminal

UTAH TTY-33


Figure 1. Interactive terminal connections to Wright-Patterson AFB from Argonne National Laboratory, The National Bureau of Standards, and the University of Utah

PAINT — ANL MODIFICATION OF THE PA300 POLYAT CM PROGRAM. INTEGRALS ARE GENERATED I N CANONICAL L I S T S FOR INTERFACE WITH THE ANL COOES OVC, KR A S AND O A S C I . BY H.BASCH, BELL LABORATORIES PA300/CDC6600 BV C.J.HORNBACK, NYU. ANL CANONICAL VERSION BY A.HINOS, A N L . ANL VERSION INPLENENTEO ON COC6600 BY R.P.HOSTENY, A N L . ANL VERSION/COC66I0 MODIFICATIONS BY O.G.HOPPER, ANL. TNIS IS THE MPAFB COC6600 CANONICAL VERSION OF A P R I L , 1 9 7 5 FOR INFORMATION OR THE LATEST WRITE-UP CONTACT O.G.HOPPER, ANL, X A R L / L J , MPAFB ,OH. * 5 * 3 3 , P H i l J - 2 5 5 - * 8 6 9 . t

DATE —

OS/07/75

TIME — 1 7 . 3 1 . 1 2 .

RUN TITLE NNO B U » CONTACT D . G . H O P P E R , X A R L / L J , MPAFB.OH*513-255-

ab initio - ACS Publications

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