LOS ALAMOS SCI ENTIFIC LABORATORY

LOS ALAMOS SCI ENTIFIC LABORATORY

of the

University of California

F LOS ALAMOS . NEW M E X I C O

b

Simulation

of

maw

the

SELS-

-K-,-

er

---

_-

_-.

. .-

on

MANIAC

I1

(SFCMA)

L+-

-

d

UNITED STATES

DISCLAIMER

DISCLAIMER

I

L E G A L

N O T I C E

This report was prepared as an account of Government sponsored work. Neither the United

Stabs, nor the Commission, nor any person actiog on bebalf of the Commission:

A. Makes any warranty or representation. expressed or implied, with respect to 1 e accu- racy, completeneea, or usefulness of the information contained in this report, or that the use of any information, apparatus, method, or process disclosed in this report may not inLrlsge privataly owned rights; or

B. Assumes any liabilities with respect to the use of. or for damages resulting from the

uae of any information, apparatus, method, or process disclosed in tbis report.

As d in the above. "person actfng on behalf of the Commissionm includes any em- ployee or contractor of the Commission, or employee of such contractor, to the extent that such employee or contractor of the Commission. or employee of such contractor prepares, dismeminatee, or provides access to, any information pvlruaat to He employment o r contract with the Commission, or hie employment with such contractor.

This report expressee the

opinions

of

the

author o r authors and does

not

necessarily reflect

the

opinions

or

views of the Los Alamos Soientific

Laboratory.

Printed in the United States of America. Available from Clearinghouse for Federal Scientific and Technical Information National Bureau of Standards, U. S. Department of Commerce

Springfield, Virginia 22151

LA-3640

UC-32, MATHEMATICS

AND COMPUTERS

TID-4500

LOS ALAMOS SCl ENTl FlC LABORATORY

of the

University of California

LOS A L A M O S NEW M E X I C O

Report written: November 1966

Report distributed: F e b r u a r y 27, 1967

Simulation

of

the SELSlOA Computer

T H I S PAGE

WAS

INTENTIONALLY

The SEL-810~ computer has been simulated on M4NIAC 11; MADCAP has .

been used a s t h e programming language. The exercise has several ob-

jectives: a d e t a i l e d knowledge of t h e l o g i c a l s t r u c t u r e of t h e SEL-810~ .

and t h e preparation of programs would be possible; t h e s u i t a b i l i t y of WCAP could be examined f o r t h i s ' t y p e of application. The two-pass assembler provided f o r t h e SEL computer was tested, and error's i n t h e o r i g i n a l versions were detected and corrected. An account i s given of other experience.

The authors wish t o thank Mark Wells and Roger Lazarus of

T-7

f o r

useful discussions of t h e MADCAP language. We a l s o thank Harold Butler

of MP-1 f o r discussions concerning t h e operation of t h e SEL computer.

One of us (J.R.P.) i s indebted t o Carson Mark f o r t h e i n v i t a t i o n

T H I S PAGE

Abstract

. . .

3

3

.

Declaratory Statements and I n i t i a l i z a t i o n

. . .

12

. . . . . .

.

4

.

Input Phase '

14

5

.

I n s t r u c t i o n Decoding and Effective Address Computation

...

16

FIGURES

Page

1. Simulation procedure

. . .

8

1. Introduction

1.1 A simulator c a l l e d S E M which i n t e r p r e t s SEL-810~ machine

language i n t o equivalent MANIAC I1 (M2) machine language has been w r i t -

t e n using

MADCAP.^

No attempt has been made t o a t t a i n maximum speed or

memory economy; r a t h e r t h e c r i t e r i a of t h e speed of programming t h e simulator and t h e c l a r i t y of t h e f i n a l program have been selected. The

,- W C A P language i s well-suited f o r t h e description as h e l l as t h e pro-

gramming of t h e subject program.

2

1.2 Given t h e SEL assembler c a l l e d MNEMBLER w r i t t e n i n modified

SEL machine language and t h e appropriate SEL loader which converts modi- f i e d t o absolute language, we may then assume t h e existence of a MNEMBLER

machine code; and a program w r i t t e n i n MNEMBLER language may be processed

as showxi i n Fig. 1.

1.3 The input-output complement of M2 i s not t h e same as t h a t of

t h e SEL computer, so compromises a r e necessary. The fast paper t a p e

reader and punch a r e compatible on t h e two computers, s o no modifica-

t i o n i s necessary. The M2 l i n e p r i n t e r has a g r e a t e r width, which causes

no severe d i f f i c u l t y , but t h e character s e t and paper control a r e s l i g h t l y

&CAP

Manual,

Group

T-7,

las Alamos S c i e n t i f i c lsboratory (1964).

2

- _{SEL-810~ Reference Manual, Fort Lauderdale, Florida (1966 )}

.

d i f f e r e n t . The proper correspondence i s given l a t e r .

The g r e a t e s t mismatch i s i n t h e ASR-33 t o Mark 3 typewriter map-

ping: No reader o r punch i s a v a i l a b l e on t h e Mark 3, and t h e r e i s a

s u b s t a n t i a l difference i n t h e s p e c i a l character s e t .

1.4 I n t e r r u p t s may be introduced i n t o t h e system by means, of a

paper t a p e giving t h e p r i o r i t y l e v e l and t h e time of t h e i n t e r r u p t i n

cycles

-

or by giving t h e s e t t i n g of t h e SEL program counter a t which.the

i n t e r r u p t i s desired. If it i s desired t h a t t h e program run without

i n t e r r u p t s , they can be suppressed by a sense s e t t i n g on t h e M2 console.

1.5 Display of t h e i n t e r n a l s t a t e of t h e SEL-810~:can . . be obtained

under W sense switch control, and changes can be introduced i n t o t h e

SEL computer memory by means of t h e _{. .} M2 W k . 1 keyboard. The a c t u a l SEL

running time can be exhibited.,

1.6 Certain programmed M2 stops i n d i c a t e possible e r r o r s i n t h e

SEL code and a r e provided a s an a i d i n debugging. The meanings of these

stops w i l l be spelled out below. The SEL program may a l s o be stopped

manually or breakpointed.

1.7 Times, i n cycles, f o r carrying out peripheral operations are

entered as parameters Nk, where k i s an integer, and a r e used i n t h e

computation of t h e a c t u a l SEL running time.

1.8

The operating speed of t h e simulator i s approximately 1000

times slower than t h e a c t u a l SEL computer. The SEL assembler c a r r i e s

out -[;he full assembly a t about two statements

per

minute.

9

. .

. . . . . . . . . . . . . . .

2. Program Organization

2.1 The general organization of the program is shown in Fig. 2, and each part is described in more detail in the following sections. A description of the self-contained procedures is also given.

2.2 The simulator is stored in the M2 disk file, and calling is carried out under standard M2 operating procedure.

2.3

Although a knowledge of certain parts of W C A P is needed to understand the program, the procedure descriptions are made independently of that facility; and a view of the simulator can be had independently.

START

(2

Declaratory Statements and

I n i t f a l i z a t i o n

Read i n SEL h-ogrm and I n t e r r u p t Tapes H a l t f o r SEL Data Tape Load Decode I n s t r u c t i o n and Compute E f f e c t i v e C - Frocess + I n t e r r u p t s and BTC I I n t e r p r e t i v e Execution of I n s t r u c t i o n (including

1/b)

4

Display SEL S t a t u s .

under Sense .Control

-1

HZ,"

I

3 . Declaratory Statements and I n i t i a l i z a t i o n

. .

3.1' A s i n most compilers, words may be of various n k b e r - t y p e s

and must be declared or implied t o be of a c e r t a i n type. The number-

t y p e s used i n t h i s si~miiatoY We:

3.11 Real: Floating Point Number

3.12 Word-Set: A 48-bit M2 word on which Bool.e@~. set.-

operations may be performed.

3.13 Label: A symbolic location of a MADCAP statement.

3.14 String: A sequence of 8-bit characters of specified

length.

They a r e declared, generally, e a r l y i n t h e program.

3;2 Also e a r l y i n t h e program parameters a r e i n i t i a l i z e d , l a t c h e s

m e s e t , and formats f o r input and output a r e declared.

3.21 N 1 through N13 a r e parameters describing t h e operation

times of various peripheral devices and should be s e t

with proper values if i n t e r r u p t t i m i n g i s t o be simu-

l a t e d properly.

3.22 The parameters prescribing when t h e d i f f e r e n t peripheral

devices

w i l l

next be a v a i l a b l e a r e i n i t i a l i z e d t o zero.

3.23 The pointers 11, 12, and I 3 on t h e i n t e r r u p t l i s t s a r e

3.24 Tag b i t 0 ( ~ e l e t n e c l e a r ) i s s e t t o one and the' r e -

~ i n i n g Tag b i t s a r e s e t on i n i t i a l zero. The Tag word

,

i s defined i n Appendix D

.

3.25 The S t a l l A l a r m enable b i t i s s e t . This b i t i s not d i s -

turbed during operation of SELMA and has t h e highest

p r i o r i t y . A l l other b i t s i n t h e i n t e r r u p t enable s e t

a r e i n i t i a l i z e d t o zero.

3.26 Alatch, a f l a g s i g n a l l i n g t h a t t h e highest a c t i v e i n t e r -

r u p t i s t o be turned off a t t h e next LOB or BRU*. i n s t r u c -

4. Input Phase

4.1 When SELMA i s c a l l e d from t h e disk, any absolute SEL tapes

should be i n t h e reader with sens'e 0 i n t h e s e t p o s i t i o n i f more abso-

l u t e t a p e s a r e t o i'ollow.

4.2 The absolute t a p e w i l l be read i n and SEIM w i l l come t o s t o p

0 i f t h e r c a r e more ab,colutc tapco, Thcoc tapco a r c i n otandard EEL

format with a l o c a l address and negative word count a t t h e s t a r t of t h e

t a p e (SEL Manual, p. D

.I,

Debug Dump Tape)

.

They w i l l be automatically

loaded a t t h e proper place.

4.3

I f sense 2 i s on, SEIMA w i l l h a l t a t s t o p 2 and p r i n t "Load

time i n t e r r u p t s . " Any time i n t e r r u p t t a p e i s loaded and sense 2

-

i s

l e f t on i n order t o maintain these i n t e r r u p t s i n an a c t i v e s t a t u s .

--

4.4

Sense 3 has a s i m i l a r a c t i o n f o r location interrupts.

4.5 ~f sense

6

i s on, s t o p

6

w i l l occur, allowing t h e operator t o

type an execution s t a r t i n g address i n t o t h e last 13 b i t s of t h e t o p con-

sole r e g i sFer d i splay.

4.6 I f sense

₆

i s off, seisse

7

w i l l de:.teruf~lc l;he s t ; u . l ; i t g address.

It w i l l be 0 (standard assembly l o c a t i o n ) if sense

7

i s off and

6677

(standard l o c a t i o n of ioadek start) i f s e t .

4.7 The last s t o p i s "a" and t h i s i s the. only s t o p which always

Go" w i l l be printed, allowing f o r any program d a t a including programs t o be assembled or loaded (which a r e d a t a t o t h e assembler o r loader programs) t o be i n s e r t e d i n t h e reader.

5.

I n s t r u c t i o n Decoding and Effective Address Computation

5.1

The i n s t r u c t i o n type i s recognized by t h e first four b i t s of t h e word and, i n t h e case where they a r e a l l zero, by t h e l a s t

6

b i t s , which then contain t h e augmented code.

. - - .

5.2 A s p e c i a l case i s made f o r t h e i n s t r u c t i o n s of o c t a l type 13 o r 17, which a r e I/O o r i n t e r r u p t type instructions.

I n

the case of

s h i f t instructions,. t h e amount of t h e s h i f t i s extracted f o r transmis- s i o n t o t h e i n t e r p r e t i v e routine.

6. Diagnostics

6.1 I n order t o a s s i s t i n debugging, c e r t a i n f a c i l i t i e s a r e made a v a i l a b l e t o t h e operator and programmer.

6.2

. I f sense

4

i s on, a t t h e completion of each SEL i n s t r u c t i o n

t h e r e w i l l b e a p r i n t o u t of t h e SEL cycle number, i n decimal; t h e i n -

s t r u c t i o n location: t h e i n s t r u c t i o n i t s e l f ; t h e e f f e c t i v e address l a s t

computed; t h e contents of t h a t address; t h e A and B accumulator contents,

a l l i n octal; and t h e contents of t h e l o c a t i o n c a l l e d Tag ( s e e Appendix

D )

i n binary.

6 . 3

Sense

5

w i l l cause p r i n t i n g of cycle and i n s t r u c t i o n location, '

-

i n decimal, and t h e word-sets EnaSle, Request, and Active i n hexadecimal

so t h a t i n t e r r u p t s can be studied.

6.4 Sense 4 and

5

may be actuated together. An example of t h i s

type of d i a g n o s t i c p r i n t o u t is:

39

1660 cp=111656 ' e l 6 5 6

c

,=034531 A=OOOOOO ~ 4 7 7 6 4 5 T ~ ~ = O O O ~ ~ O O O O O O O O ~ O O O ~

6.5 I n order t o breakpoint a SEL i n s t r u c t i o n , e n t e r t h e i n s t r u c -

t i o n l o c a t i o n i n t h e f i r s t 16 b i t s of t h e panel a r r a y i n o c t a l and s e t

sense 9. I f t h e program counter assumes t h e value on the.pane1, t h e r e

w i l l be a s t o p

9

before performing .the i n s t r u c t i o n . S e t t i n g sense

9

w i l l

running since it i s immediately interrogated and r e s e t . Only one break-

point a t a time can be entered.

6.6

Sense switch

8

i s t h e "manual" switch and w i l l cause a h a l t

a f t e r each SEL i n s t r u c t i o n . This occurs a f t e r any diagnostic p r i n t re-

quested by sense 4 o r

5 .

The console w i l l display, a f t e r every stop,

-

t h e i n t e r n a l s t a t e of t h e SEL computer (Appendix E ) . I f now t h e f e t c h

switch i s . depressed, S E N w i l l resume simulation t o t h e next s t o p o r

w i l l run on .automatic, as requested on sense

8.

6.7 The S t a l l Alarm i s implemented. as a trap t o a leveb designated

7. I n t e r r u p t Processor

7.1 If sense 2 or 3 i s on (Sec. 4 ) , t h e i n t e r r u p t l i s t i s i n t e r r o -

gated3 and a l l time i n t e r r u p t s whose cycle i s l e s s than or equal t o t h e

machine cycle a r e entered i n t o Request. I f t h e location i n t e r r u p t l i s t

contains t h e programscounter setting, an i n t e r r u p t i s s i m i l a r l y entered.

7.2 An attempt t o i n t e r r o g a t e an empty l i s t w i l l r e s u l t i n s t o p 12,

which may be overridden by r e s e t t i n g t h e sense switch and continuing.

7.3 If t h e i n t e r r u p t suppress occurring s f t e r c e r t a i n i n s t r u c t i o n s

i s on, it i s turned off, and S E N continues without f u r t h e r ' a c t i o n . .

7.4 An i n t e r r u p t i s processed by t h e i n t e r r u p t procedure described

8. Instruction I n t e r ~ r e t i v e Routines'

8.1

These are i n t e r p r e t i v e routines which simulate each SEL in-

.. s t r u c t i o n . The i n s t r u c t i o n s a r e sixteen b i t 2I.s complement notation;

t h e r e f o r e , m a u y of t h e i n t e r p r e t i v e routines involve word-set opera- t i o n s .

8.2 Memory referencing i n s t r u c t i o n s use t h e procedure e f f e c t i v e t o g e t t h e f i n a l e f f e c t i v e address before entering t h e , i n t e r p r e t i v e routine.

8.3 S h i f t i n s t r u c t i o n s use s h i f t t o update t h e cycle number and t o

-

transmit t h e magnitude of t h e s h i f t .

8.4 The TO1 I n s t r u c t i o n s e t s a location c a l l e d Alatch t o t h c vabuc

corresponding t o t h e highest a c t i v e i n t e r r u p t . This i n t e r r u p t i s r e s e t a t t h e next LQB o r B R i n s t r u c t i o n . ~

9.

110 I n s t r u c t i o n s

9.1 The 110 i n s t r u c t i o n s f o r each peripheral device a r e separate

routines.

9.2 The TEU i n s t r u c t i o n s a r e not implemented, except f o r t h e

l i n e

p r i n t e r , since t h e 110 i n t e r r u p t w i l l be used and each d e v i c e . w i l 1 be

. .

connected t o a separate l e v e l so t h a t no ambiguity of u n i t w i l l occur.

9.3 Conflicts on t h e l i n e p r i n t e r i n CEU i n s t r u c t i o n s a r e detected,

and s t o p e w i l l s i g n a l t h e i r occurrence. The CEU "formst N" causes a

one-line advance, only.

9.4 The meaning of t h e d i f f e r e n t stops can be found i n Appendix C .

9.5 The t e l e t y p e routine uses t h e procedure convert t o e s t a b l i s h

t h e correspondence between t h e Mark 3 typewriter and t h e ASR-33 code.

Refer t o Appendix F f o r t h e equivalence o f , c e r t a i n characters. The typ-

ing of an i l l e g a l character causes a s t o p

7

and ignoring of character so

continuation, i s possible.

9.6 The timing i s c a r r i e d out u ~ i n g t h e parameters N 1 through

N 13 l i s t e d i n Appendix G.

9.7 I t i s possible t o i n s e r t a F l e x m i t e r - g e n e r a t e d tape i n t h e

f a s t reader and have it i n t e r p r e t e d as SEL code. This i s accomplished by

9.8

Whenever an I/O i n s t r u c t i o n i s performed, t h e new time a t

which t h e u n i t w i l l be ready i s i n s e r t e d i n t o t h e 1/0 i n t e r r u p t l i s t

a t t h e i n t e r r u p t l e v e l appropriate t o t h e u n i t . The i n t e r r u p t proc-

10. Procedures

10.1 Complement

The i n t e r s e c t i o n of G with t h e 2's complement of F i s t r a n s -

mitted without s i d e e f f e c t s . ,

10.2 S h i f t

s h i f t (none; p, C , Cycle)

The magnitude of t h e s h i f t i s transmitted from SEL i n s t r u c -

t i o n p

(MANIAC

C );and a s a s i d e e f f e c t , Cycle i s advanced t h e appro-

P p r i a t e amount. 10.3 I/O Timing twx (Select, Delay; a l l )

-

If t h e . w a i t f l a g i n t h e

110

i n s t r u c t i o n i n F i s

on,

s e t Cycle

t o max'(Cycle, Tunit) where Tunit i s t h e l a s t s e t ready time. Cycle

+

Delay, t h e next ready time, i s s e t i n t o Tunit.

I f t h e w a i t f l a g i s not on but t h e u n i t i s ready, advance p

by 1 ( s k i p ) a,nd advance Tunit.

I n these cases, Mode i s s e t t o S e l e c t with t h e meanings f o r

t h e ASR-33

-

1 keyboard mode

0 c l e a r mode

Unit not ready and no wait f l a g causes an e x i t with no s i d e ef- f e c t s . Tag 14 i s s e t i f t h i s l a t t e r e x i t occurs.

10.4 Typewriter Character Conversion

Convert (T; ~ a g )

Tag

5

i s s e t t o 0 f o r output and 1 f o r input before entry.

I n t h e c a s e of output, t h e leftmost

8

b i t s of t h e SEL word Wd a r e

converted t o t h e appropriate MANIAC character s t r i n g and outputted t o

%:he typewriter (no punch). Contrary t o t h e statements i n t h e manual,

output t o t h e l i n e p r i n t e r i s from t h e r i g h t

8

b i t s .

On input, characters typed on t h e Mark

3

typewriter a r e converted

t o an 8 - b i t character r i g h t - j u s t i f i e d . The character formation i s de-

layed u n t i l the change i n case has been completed.

Case designation i s c a r r i e d i n t a g

3

and c a r r i e s between procedure

c a l l s s o t h a t t h e current s t a t e can be determined and unnecessary case

change a c t i o n s a r e eliminated.

It'

an i l l e g a l character i s input, T i s s e t t o zero and SELMA w i l l

h a l t on s t o p

'7.

.A f e t c h of t h e next i n s t r u c t i o n w i l l allow another t r y

with case remembered from t h e i l l e g a l a c t i o n ( i , e . present s t a t u s ) .

See Appendix F f o r character correspondences,

10.5 E f f e c t i v e

e f f e c t i v e (none; B, C, p )

This procedure computes t h e e f f e c t i v e address of t h e SEL i n -

s t r u c t i o n a t l o c a t i o n p whose image i s stored i n

MANIAC

location C

P '

It w i l l map, index with B, and compute t o any i n d i r e c t depth adding 1.

If t h e f i n a l e f f e c t i v e address o r t h e e f f e c t i v e address a t any in- d i r e c t l e v e l exceeds 8192, t h e words:

"Address exceed 8192 a t pxxxx"

w i l l be printed and MANIAC w i l l h a l t .

The l o c a t i o n 8192 r a t h e r than 8191 is' used,because t h e wired-in

SF@ i n s t r u c t i o n associated with t h e i n t e r r u p t hardware i s executed a t

t h e a r t i f i c i a l location 8192.

The procedure has no s i d e e f f e c t s . 10.6 Basic I n t e r r u p t Routine

i n t e r r u p t (none; Active, Enable, Request, p, C, c y c l e )

If t h e i n t e r r u p t l e v e l "Level" i s enabled and no higher l e v e l s

a r e active, t h e wired-in i n s t r u c t i o n SPEPL i s executed a t SEL l o c a t i o n

8192 and both t h e "active" and "request" b i t s . f o r that l e v e l a r e s e t .

If Level does not meet this condition, t h e request b i t i s s e t and

11. Concluding Remarks

-

11.1 The MADCAP language was p a r t i c u l a r l y suited t o t h e writing

of t h i s simulator. The s e t operations were of g r e a t value and had a

naturalness which .made them simple t o use. The g r e a t generality of t h e

various types.of conditional statements helped i n making t h e l o g i c of '

t h e program simply and c l e a r l y exprcooiblc,

11.2 Because-the W C A P statements a r e expressed so easily, we

b e l i e v e t h a t l o g i c a l and s y n t a c t i c e r r o r s a r e l e s s l i k e l y t o occur and,

indeed, it was our experience t h a t t h e debugging time was remarkably

s h o r t e r than f o r other formal languages. .

11.3 I n order t o give support t o these statements, we present t h e

f ollmi1Ig daL&:

Number of compwd MADCAP statements 710

Programming

7

man-weeks

MANIAC I1 debugging 19.5 hours

51 sessions

U t i l i z a t i o n time, t o b L e 23.3 hours

"Add Memory t o B Accumulator"

Fig. 3. Program sample of MADCAP statements.

Comments

Save contents of e f f e c t i v e address. S = 0 i f both sign b i t s {15] of F and B accumulators a r e t h e same; otherwise S

f

0.

Form algebraic sum of F and B and truncate t o

16

b i t s .

I f t h e signs of F and B a r e now

d i f f e r e n t and S = 0, overflow has occurred.

Set overflow l a t c h t o 1. Result t o B accumulator.

Exit t o advance cycle and program

counter

.

S t a t ezent number #1400 - #1401 #1402

#140 3

#14& Madcap Statement F = Ce; S = (F

n

[ l 5 ] ) A ( B

n

{15])

F = word (number ( F )

+

number ( B ) ) fl

16

unless F

n

[15]

#

B

n

{l5), and

s

=- 0, go t o #1403.

TW IJ

[4]

-

~ a g

B = F

APPENDIX A

Timing Parameters

The following 110 execution times a r e .to be s e t i n SEIMA t o ensure

proper

u M t i n g

of

cycle,

N 1 F i l l reader buffer

N2 Reader enable

N 3 Punch cycle

N4

TWX input (read buffer f i l l time

-

e i t h e r mode)

N5

TWX

output time

N6

S e t TWX mode

N 7

Line p r i n t e r time

iu8

W c h turn-on

Ng

' Next page N10 ' Next l i n e N 1 1 . E~w,Irle - y r l r r l ; ~ burr er N12 C l e m buffer ( p ~ i . n t . e r )

Sense Lights

The f i r s t t e n sense switches on t h e MANIAC console a r e interrogated

by S E W and can be used t o a l l o w various simulator operation nodes. I f

a console s t o p occurs a s a r e s u l t of one of these sense interrogations,

t h e console w i l l display t h e i n t e r n a l s t a t e of t h e SEL .computer, Opera-

t i o n can be resumed by depressing t h e Fetch switch. Sense

-

-

Set Condition

0

-

Load Absolute

--

and H a l t . There i s no h a l t before t h e f i r s t

absolute tape i s r e a d , ~ ~ it i s assumed t h a t t h e r e i s an

:absolute tape i n t h e reader a t t h e start of SELM4 i f t h i s

sense i s s e t . A s long as sense 0 i s s e t , SEIW w i l l h a l t

a t s t o p 0 f o r more tapes. Sense 0 can' be r e s e t a t any 0 stop. The format f o r an absolute tape i s t h a t given i n

Appendix D of t h e SEL manual f o r t h e '"Debug Dump Tape."

This t a p e can a l s o be loaded with t h e SEL Debug Loader

Program.

Flexmiter-Generated !Tape in,Reader. On reader AIP and

--

MIP instructions, t h e characters read a r e assumed t o be

F l e x m i t e r characters and ' conversion t o ASR-

33

equiva-

l e n t s a r e made automatically. The equivalence i s t h a t of

Appendix I?.

Sense

-

-

Set Condition

2

-

Time I n t e r r u p t s . S E m w i l l p r i n t "Load time i n t e r r u p t s , "

e j e c t a page, and come t o s t o p 2. The Time I n t e r r u p t tape should be i n s e r t e d before continuing operation. Time in- t e r r u p t s w i l l be processed during t h e program a s long a s t h i s sense i s l e f t on.

3

Location I n t e r r u p t s . S E W w i l l p r i n t "Load location

nnzerlpupce,l'

eyecr, a page, -6 come t o s t o p

3 .

The Luca- t i o n I n t e r r u p t tape should be i n s e r t e d before continuing operation. Location i n t e r r u p t s w i l l be processed during t h e program

as

l o w

as

t h i s sense i s l e f t on.

4

-

P r i n t Standard Diagnostics. After each SEL instruction, p r i n t a l i n e displaying Cycle, p, C

,

e, Ce, A, 8, and

P

Tag, consecutively. T w i s displayed a s a binary number.

5

-

P r i n t I n t e r r u p t D i q p o s t i c s

.

After each SEL instruction, p r l n t a l i n e dispiaying Cycle, p, Enable, Xequest, and

Active, consecutively.

It.

sense 4 i s a l s o set, both diag- n o s t i c s a r e printed and a l i n e i s skipped a f t e r t h e i n t e r -

rupt diagnostics.

6 H a l t f o r S t a r t i n g Address. Causes console s t o p

6.

m e

- 7

16-bit number entered. i n t o console position 2 ( s e e Ap-

Sense

.

,

-

S e t Condition

7

--

S t a r t a t Loader. The program dl1 start a t 1 5 0 2 5 , ( o c t a l ) .

This i s t h e l o c a t i o n of t h e loader i n t h e standard s t a t e .

I f t h e switch i s i n t h e r e s e t position, t h e s t a r t i n g loca-

t i o n i s 0, t h e assembler s t a r t i n g address i n t h e standard

state'. S e t t i n g of sense

6

w i l l a l w a y s override this sense.

Manual Operation. .The computer w i l l h a l t a f t e r each SEL

i n s t r u c t i o n a t console s t o p

8

(Sec. 6 ) .

sense switch replaces t h e MBMClC Manual/~utomatic

Switch.

9

--

Enter SEL Breakpoint. When t h i s switch i s moved t o "set1',

t h e f i r s t 16 b i t s of t h e panel a r r a y a r e entered as a break-

point (Sec.

6 ) .

10 Suppress &I I n t e r r u p t s . A l l i n t e r r u p t s from 110 devices

a r e suppressed. Since detection of

110

i n t e r r u p t s 'can be

time-consuming, t h i s sense should be s e t i f no

110

i n t e r -

r u p t s a r e expected i n order t o ensure b e t t e r S E M running time.

Absolute Code Modification. When t h i s switch i s "set"

_{- . . -}

a f t e r a console stop, t h e paper t a p e i n t h e reader i s used t o modify t h e SEL absolute code i n t h e SEL simulated

memory. The format of t h e paper tape i s

a. number of corrections i n decimal followed by a car-

Sense

-

S e t Condition

-

b. l o c a t i o n t o be modified expressed i n s i x o c t a l d i g i t s

followed by a Tab.

c . contents, i n o c t a l , of t h e modified location followed

by a carriage r e t u r n .

d. s t e p s b and c &e repeated f o r remaining modifica-

APPENDIX C

SEL Console Stops

Console Stop Meaning

0 Load, n e x t a b s o l u t i tape ~ri' r:-+sel; (seilse 0 ) .

1 HLT program h a l t . (Cycle count i s r e s e t t o 0 .)

2 Load time i n t e r r u p t s (sense 2 ) .

3 Load location i n t e r r u p t s (sense 3 ) .

4

Program counter overflow (8192).

5

P r i o r i t y I n t e r r u p t group t o o l a r g e .

6 Enter s t a r t i n g address i n S (sense 6 ) .

7

I l l e g a l 110 character ( d e l e t e d )

.

8 Manual s t e p a l t e r a t i o n s t o p ( s e t d i a l t o 0 t o continue)

(sense 8 ) .

Panel breakpoint stop.

a . I n s e r t data tape and go.

b

.

Incorrect peripheral u n i t number.

c. Non-implemented

TEU.

d , Peripheral u n i t i n wrong mode.

e. P r i n t e r c o n f l i c t condition.

f

.

P r i n t e r "input" called.

Console S t o p Meaning

APPENDIX D

Tag Meanings

The word "Tagl',which i s displayed i n console p o s i t i o n 3 a f t e r each

SEL stop,has t h e following bit-by-bit meaning. I n i t i a l l y , t h e r e i s a

one i n p o s i t i o n 0 with t h e r e s t zero.

B i t

Location "0" meaning "1" meaning

0 Neutral ~ e l e t y p e Clear Mode

1 Neutral Teletype Keyboard Mode

2 Neutral Teletype Reader Mode

. ~

NOTE: I n i t i a l l y b i t 0 i s a one and b i t s 2 and 3 a r e

zero. CEXJ a c t i o n s can cause any of b i t s 0, 1,

and 2 t o be set; t o a one but t h e other two w i l l

then be s e t t o zero.

Mark 3 i n Upper Case Lower Case '

NOTE: The ASR-33 equivalent of Mark 3 input depends on

t h e case of t h e Mark 3 character, so t h e case must

be remembered from character t o character on input.

S E N assumes t h a t t h e i n i t i a l s t a t e i s upper case.

No overflow Overflow

Character Ou,tput Character Input

sit

.Location "0" meaning "1" meaning

NOTE: Communicates t o convert procedure whether con-

version i s f o r input o r output.

Carry "0" Carry "1"

NOTE: S e t by CSB i n s t r u c t i o n , r e s e t by AMA and SMA.

Neutral Presence of i n t e r r u p t

t o be processed

Reader disabled Reader enabled

hrnch disabled Pu~lch disabled

Neutral . BTC on

not used

,14 NO I/O a c t i o n I/O a c t i o n

. . , NOTE: The.TWX procedure

-

w i l l s e t t h i s t a g t o i n d i c a t e

. . . .

. . . . . ,T/O u u l ; i ~ $ . A " i i ~ I , 1bti&y1'

,

no ~ u 1 . k I/O o ~ * s E ~ -

t i o n w i l l s e t t h e t a g t o zero, otherwise t o one.

.

15

I n t e r r u p t Suppress o f f Suppress on

NOTE: The i n t e r r u p t hardware i s suppressed a f t e r SPB,

PIE, PID, TOI, and CSB instructions. This tag

APPENDIX

F

Teletype

-

Mark 3

-

P r i n t e r Character Equivalence

A l l t e l e t y p e characters have t h e i r Mark

3

and p r i n t e r equivalents except:

Teletype IvhI-k

3

-

( c on p r i n t e r ) f ( i on p r i n t e r )

n

(; on p r i n t e r ) z

(n

on p r i n t e r ) CR (with l i n e feed)

-

hate

that

the

l i n e feed i s not automatic on t h e ~ e l e t ~ ~ e and must be ex- p l i c i t l y struck. Thus each new l i n e w i l l bagln wlth

'thtr

~ j i i h ~ l i.-r even