Scientific Development Corporation Minivac 601 User manual

Getting acquainted with
M i n i v a c 6 0 1
SCIENTIFIC r. j |
DEVELOPMENT 3 T ir S t S te p
corporation toward the exciting world of electronic
w— data processing via digital computers

I he MIN I VAC 601 computer and
this book are used together to demonstrate
the operation of digi+a computer components
and to teach princip es basic to their use.
As you become fami iar with M INIVAC 601
and understand its re ationship to arge
digita computers, you wi be performing
the operations basic to a modern e ectronic
data processing machine.
This is the first in a series of books
using M INIVAC 601 to demonstrate the
fundamenta s of modern digita computers.
This book acquaints you with M INIVAC 601 .
The second book in this series re ates
the components of M INIVAC 601 to
corresponding parts of a arge commercia
digita computer. Other books enab e
you to use M INIVAC 601 to discover
how these parts function to make
decisions, to do arithmetic, and
to do practica work for men. A
book of games which may be
p ayed with M INIVAC 601
is a so provided.
CONTENTS

I ) POWER SUPPLY ......................................................................................... 3
7.) PROGRAMMING WIRES ....................................................................................................... 4
C osed Circuit' Princip e ........................................................ 4
Using the Programming Wires ............................................. 4
Experiment 1: Use of Programming Wires ................... 5
Wiring Shorthand ......................................................................... 5
3fc) LIGH TS . ...................... 6
Experiment 2: Sing e Light Operation ....................... 7
■ 4 ) PUSHBUTTONS...................................................................................................................... 8
Experiment 3: Pushbutton Operation ........................... 9
Experiment 4: Series C ircuit ........................................... |q
Experiment 5: Para e Circuit ............................................ u
5) RELAYS ...................................................................................................................... 12
Experiment 6: Manua Re ay Operation. . . ............ 13
E ectrica Operation of the Re ay ..................................... 14
Experiment 7: E ectrica Re ay Operation 15
Experiment 8: One Re ay Contro s Another ..........
Experiment 9: A Re ay Contro s Itse f ........................... 17
PAGES
__ ___ESP(i5Pi
f SLIDE
SW ITCHES. .......................... * ............ . ......................... . ........................... 18
Experiment 10: S ide Switch Operation ........................ 19
'ROTARY SWITCH...................................................................................................................... 20
Experiment 11: Manua Operation of
Rotary Swi tc h ......................... 21
Motor Drive ....................................................................................... 22
Resistors ............................................................................................ 22
Decima Input-Output ........................................................... 22
Experiment 12: Basic Motor Operation .................... 23
Experiment 13: Motor Driven Rotary Switch. • • • 23
Pu se Generator ......................................................................... 24
Programmer .................................................................................... 24
Experiment 14: Motor Reversing ........................................ 24
8) M ATRIX ..................................................................................................................... 25
9) AUXILIARY TERMINALS ........................................................................................... 25
1 0 ) LO O KIN G AHEAD WITH M INIVAC 601 ................................................................................................................ 26
Summary: Book 1 ...................................................................... 26
Book II: What is a Digita Com puter? .................... 26
Book III: How Computers
Make Logica Decisions 26
Book IV: How Computers Do Arithmetic ................. 27
Book V: How Computers Work for Man .................... 27
Book V I: MINIVAC Games ................................................... 27
PROBLEMS FOR M INIVAC 601 ........................... 28
to 32

The Mini vac Manua was prepared and edited by the staff of
Scientific Deve opment Corporation
First Printing—August, 1961
EX LIBRIS ccapitalia net
Copyright (c\ 1961 by Scientific Deve opment Corporation, 372 Main Street, Watertown, Massachusetts

POWER SU PPLY
he power supp y converts the 110-vo t AC power obtained
from a standard e ectric out et in your home to a safe working
eve of 12 vo ts DC. This ow vo tage DC is used to
power M INIVAC and is connected to a termina s +
and - on the power pane . Most toy e ectric trains
use the same ow-vo tage power as M INIVAC and
therefore working with the MINIVAC is as safe as
operating an e ectric train.
The POWER SWITCH is
used to turn power ON and OFF.
The power shou d be OFF when
ever you are wiring the
computer. Fo owing this
practice w i estab ish good
working habits and wi he p
to prevent accidenta short-
circuits. The power must be
turned OFF when the computer
is not in use. The red power ight
shows when the power is O N .
The red button above the power switch abe ed CIRCUIT BREAKER*
is a safety switch which automatica y turns off the power supp y
when it is over oaded. An over oaded circuit or a short-circuit
wi cause the circuit breaker to "b ow" just ike a househo d
fuse. A short circuit occurs when + is wired direct y to -
without a component in between. The power supp y
may be restored to norma operation after a short-
circuit by changing the fau ty wiring and then
pushing the red circuit-breaker button back in.
CAUT/o n :
Do NOT ho d the circuit-
breaker button in if it
continues to "b ow." Turn
power off and determine the
cause for drawing excessive
current before proceeding
with the experiments.
N ow ... .p ug the POWER CORD into
a standard 110-vo t AC (NOT DC)
out et, and you are ready to
GET ACQUAINTED
WITH M INIVAC 601 ...........
3

w
2PROGRAMMING W IRES
^Programming wires of different engths are provided to make e ectrica
( programming) connections between various termina s on M INIVAC 601 .
These wires estab ish c osed e ectrica circuits and route the current through
one or more components to create a desired computer circuit.
Each component in the computer
is connected to nearby termina s
by permanent connections made
under the computer pane .
The components may be interconnected by
inserting programming wires into the termina s.
Each termina has two ho es side-by-side which
are connected together underneath the computer
pane . Programming wires may be p ugged into
either (or both) ho es of the termina . A
programming wires are co or-coded by ength.
CLOSED CIRCUIT PRINCIPLE
For any e ectrica device to operate, it is
necessary for e ectrica current to f ow
THROUGH the device. A c osed e ectrica
circuit must be estab ished to et the
e ectrons f ow from the negative power
supp y termina ( - ) through the
component to the positive power supp y
termina ( + ). Thus, a e ectrica
components on the M INIVAC 601 require
at east 2 connections to operate.
AElectrons our
Electrons IN
USING THE PROGRAMMING WIRES
The programming wires are used to connect
various components of M INIVAC 601 . C osed
circuits are wired through the termina s provided
on the conso e for each component. Each
termina is identified by a etter printed be ow
it, and by the number printed at the
top of the section in which it is ocated.
This makes possib e easy identification of
termina points when wiring components
together in future experiments. We are
now ready to use the programming wires.
4

EXPERIMENT |
OF PROGRAMMING WIRES
his experiment demonstrates the use of programming
wires to make connections on MINIVAC 601 .
y Take two programming wires. Grasp one
end of the first wire firm y between your
thumb and forefinger.
Connect this end of the programming
wire to termina 1+ on the
computer pane by pushing
it into one of the two ho es
just be ow the + in section 1
of the computer.
3 ) Take the other end of this program
ming wire and connect 1+ to
termina 1A by pushing it
into one of the two ho es
just above the etter A in
section 1 of the computer.
^ /S im i a r y, connect termina 1 B to
termina 1- with the second programming
wire. These connections cause amp 1
to ight when the Power Switch is turned on.
This simp e circuit is discussed
further in Experiment 2.
Disconnect the programming wire by pu ing both ends from the
computer termina s. Do NOT disconnect the program
ming wires from the conso e by pu ing on the wire
because the wire may break. A programming wires
shou d be disconnected after each experiment or prob em.
WIRING SHORTHAND
A W IRING SHORTHAND is used to indicate connections which are to be
made on the computer by simp y writing the two termina designations
with a s ash in between. In Experiment 1, termina 1 + was connected
to termina 1A. This is written in shorthand -------- — ■ , /
A series of such shorthand wiring instructions wi be given to ' / 1/^
describe the wiring of a comp ete circuit.
5

< identica ights Iabe ed
"Binary Output" are used in
M INIVAC 601 to show what is
happening in various parts of the
computer. A ight w i come on when
is connected in a c osed circuit so
rrent f ows through the ight.
This a ows the computer to te an operator what
it is doing and to disp ay the answer to a computer prob em,
Each ight is identified by the section
number direct y above it.
In order for a ight to turn ON (to ight),
current must f ow THROUGH the ight.
The e ectrons must f ow IN on one wire
and OUT on another wire. This is the
c osed circuit princip e for ights.
The termina s abe ed A and B on either side of
each ight are used to supp y the e ectrica
power to turn the ight O N . A ight comes
ON when termina A is connected to one
power supp y termina ( + or - ) and termina
B is connected to the other power supp y termina ( - or + ).
When the circuit is
OPENED
fhe light is OFF
l^o Connection
U § h t
off
When the circuit ig
CLOSED
the lig/nt comes ON >o )
* \ V '
* \

— I
EXPERIMENT 2
1+
I -
SINGLE LIGHT OPERATION
his experiment demonstrates the operation of
a sing e binary output ight.
i; Using two short programming wires,
make the connections 1+/1A and 1- / 1B.
Turn the power switch ON (be sure
the main power cord is p ugged into a
proper out et). Light 1 comes O N ’
because current f ows through the ight.
V
1A
Turn the power switch OFF and
disconnect the programming wires.
Power shou d be turned OFF and
a programming wires shou d be
disconnected after each experiment
is comp eted.
V Any of the ights may be operated by
connecting programming wires from + to A
and from - to B just as was done for ight 1.
Make connections to two or more ights at once.
IB (The circuit diagram ooks ike this)
The ights are used in ater experiments to
represent numbers. The ight OFF wi represent
a zero ( 0 ) and the ight ON wi represent a one ( 1 ).
The numbers zero ( 0 ) and one ( 1 ) are the on y numbers
used in the binary number system, and it is for this
reason that the ights are abe ed "Binary Output."
Binary numbers and their use in digita computers
be taken up ater.
Binary Number System
0FF= 0
' " • v
S L ■
0 N = |
W
7

PUSHBUTTONS
he section of the computer pane abe ed "Binary Input" contains
six identica pushbuttons which are used by the operator to supp y
information to the computer. The pushbuttons may be used to te the
computer what to do, or to indicate the va ue of input numbers.
Pushbuttons may be used to contro the other components of M INIVAC 601
Each pushbutton is identified by its section number on the computer pane .
Each of the six binary input pushbuttons has three termina s ocated direct y
above it on the computer pane . Each termina is connected under
the pane to a contact. The termina s are abe ed X , Y and Z .
The three contacts for each of the six
pushbuttons are a connected to termina s in the same manner:
When the pushbutton is UP, an e ectrica
connection is made between termina s Y
and Z . When the pushbutton is DOWN,
the e ectrica connection is switched to
termina s Y and X . Termina Y is connected
to the "common" contact and is a ways used when
the pushbutton is connected in a circuit.
When a pushbutton is shown in a circuit
diagram, the contacts are ALW AYS shown
with the pushbutton UP - in the "norma y
c osed" (N .C .) position. Notice that
termina s X and Y are not connected when
the pushbutton is UP, and that termina s
Y and Z are not connected when the
pushbutton is DOW N.
up= y z
i r :
j!*2.
Dowm=x/y
The fo owing experiments demonstrate basic circuits in which
one or two pushbuttons are used with a ight.
♦ N