CCS 2501 User manual

Owner’s
Manual
Model
2501
Mother
Board
California
Computer
Systems

TABLE
OF
CONTENTS
I
Features
1
II
Operating
Instructions
2
III
Theory
of
Operation
3
IV
Maintenance
4
V
Parts List
5
VI
Schematics
6
Warranty
7
I
FEATURES
-12
Slot
Capability
-All
S-100
Connectors
Included
-Low
Inductance
Interconnect
to
Reduce
Signal
Noise
and Crosstalk
-Active
Termination
of
All
Bus
Lines
to
Further
Reduce
Signal
Noise
and
Line
Reflections
-Distributed
bypassing
of
All
Power
Lines
-Solder
Mask on Both
Sides of
Board
-Silkscreen
of
Reference
Designations
-Simple
Strong
Board
Mounting
-Criss-Cross
Bus
Lines
on
Both
Sides
of
Board
-All
Holes
Plated
Through
-Solder Plated
Circuit
Area
1

II
OPERATING
INSTRUCTIONS
2-1
The
model
2501A
is
packaged
and
shipped
in
a
standard
cardboard
container
with
styrofoam
inserts
to
prevent
damage.
Upon
receipt
of
the
instrument,
a
thorough
inspection
should
be
made
to
reveal
any
possible
shipping
damage.
If,
for
any
reason,
the
instrument
must
be
returned
to
the
factory,
the
original
ship¬
ping
container
should
be used.
2-2
Before
applying
power
to
your
motherboard,
it
must
be
securely
fastened
in
place
using
12
screws,
six
on
each
side.
Care
must
be
taken
that
none
of the
circuitry
on
the
bottom
of
the
board be
allowed
to
contact
ground.
Next,
power
must
be
securely
connected
to
the
board
using
the
connections
supplied.
It
is
vital
that
the
correct
voltages
are
applied
to
the
correct
points
,
or
destruction
to
your
computer
system
will
result.
See
Fig
A
Marked
on
the
circuit
board
are
the
nominal
voltages
to
be
applied
at
each
point.
The
+8
supply
will
normally
be
between
+8
and
+12
depending
upon
the
current
requirements.
The
+16
and
-16
supplies
will
normally
be between
16
and
25
volts
depending
upon
the
load.
DO
NOT
EVER
APPLY
REVERSED
VOLTAGES
OR
EXCESSIVE
VOLTAGES
LEST
IRREPARABLE
DAMAGE
MAY
OCCUR
TO
YOUR
SYSTEM.
100
PIN
SOCKET
J
lllllllllllllllllllllllllllllll
POWER
CONNECTIONS
2

Ill
THEORY
OF
OPERATION
GENERAL
The
model
2501
is
a
12
slot
motherboard
for
use
in
S-100
bus
systems.
It
has
several
design
features
to
optimize
system
operation.
A)
Distributed
bypassing
of
all
power
lines
to
minimize
crosstalk
through
the
power
l
ines
.
B)
Active
termination
of
all
signal
lines
to
minimize
signal
reflections.
C)
Newly
developed
trace
pattern
to
minimize
pulse
ringing.
ACTIVE
TERMINATION
Active
termination
is
achieved
by
returning
all
94
signal
lines
through
separate
330
ohm
resisters
to
a
regulated
+2.4
volts
DC
(See
Fig
B
)
This
means
that
all
signal
lines
are
HIGH
unless
de¬
liberately
pulled
LOW,
and
that all
lines
see
the
same
load
rather
than
being
left
in
an
indeterminate
state.
3

TRACE
PATTERN
If
you
examine
the
trace
pattern
carefully,
you
will
notice
several
features.
First,
all
pins
are
connected
on
each
side
of
the
board.
ie-pin
33
of
every
socket
is
connected
together
on
the
top
of the
board
and
on
the
bottom
of the
board.
This
"double-path"
effectively
halves the
line inductance.
Second,
each
trace
is
maintained
as
wide
as
practicable
further
reducing
line
inductance.
Minimizing
line
in¬
ductance
is
important
as
inductance
causes
ringing
on
signal pulses,
creating
system
errors.
Third,
the
traces
on
the
top
and
bottom
of
the
board
are
in
a
criss-cross
pattern
resulting
in
a
quasi¬
twisted
pair
for
each
signal
line,
minimizing
noise
pickup
and
crosstalk
with other lines.
All
of
this
effort
in
designing
the
trace
pattern
in
conjunction
with the
active
terminations
results
in
signals
with
low
noise,
minimal
ringing,
and
low
line
reflections
along
with
its
concomitant
improved
system
operation.
IV
MAINTENANCE
With
proper
care,
your
model
2501A
motherboard
should
last
a
long
time
giving
a
minimum
of
trouble.
The
unit
should be cleaned
periodically
so that
dirt
and
grime
do
not
build
up
and
short
out
either
the
power
supplies
or
the
signal
lines.
When
doing
this,
be
sure
that
power
is
removed
from
the unit.
This
would
be
a
good
time
to
check
for
loose
hardware and
tighten
as
necessary.
4

V
PARTS
LIST
1.
1
PC
Board
2.
12
Sockets
3.
14
Resistor
Packs
4.
2
Resistors
220
ohms
1/4
w
5.
19
Capacitors,
Tantalum
6.
1
Regulator
C.C.S.
02501-0002A
5

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J
Schematic
250
1
A
S-
1
00
MOTHER BOARD

LIMITED WARRANTY
California
Computer
of
its
products
that
Systems
(CCS)
warrants
to
the
original
purchaser
(1)
its
CCS
assembled
and
tested
products
will
be
free
from
materials
defects
for
a
period
of
one
(1)
year,
and
be
free from
defects
of
workmanship
for
a
period
of
ninety
(90)
days;
and
(2)
its
kit
products
will
be free
from
materials
defects
for
a
period
of
ninety
(90)
days.
The
responsibility
of
CCS
hereunder,
and the
sole
and
exclusive
remedy
of
the
original
purchaser
for
a
breach
of
any
warranty
hereunder,
is
limited
to
the'
correction
or
replacement
by
CCS
at
CCS's
option,
at
CCS's
service
facility,
of
any
product
or
part
which
has
been returned
to
CCS
and
in
which
tnere
is
a defect covered
by
this
warranty;
provided,
however,
that
in
the
case
of
CCS
assembled
and
tested
products,
CCS
will
correct
any
defect
in
materials
and
workmanship
free
of
charge
if
the
product is
returned
to
CCS
within
ninety
(90)
days
of
original
purchase
from
CCS;
and
CCS
will
correct
defects
in
materials
in
its
products
and
restore
the
product
to
an
operational
status
for
a
labor
charge
of
$25.00,
orovided
that
the
product
is
returned
to
CCS
within
ninety
(90)
days
in
the
case
of
kit
products,
or one
(1)
year
in
the
case
of
CCS
assembled
and tested
products.
All
such
returned
products
shall
be
shipped
prepaid
and
insured
by
original
purchaser
to:
Warranty
Service
Department
California
Computer
Systems
250
Caribbean
Drive
Sunny
vale^galifornia
CCS
shall have
the
right
of
final determination
as
to
the
existence
and
cause
of
a
defect,
and
CCS
shall
have
the
sole
right
to
decide
whether
the
product
should be
repaired
or
replaced.
This
warranty
shall
not
apply
to
any
product
or
any
part
thereof
which
has been
subject
to
(1)
accident,
neglect,
negligence,
abuse
or
misuse;
(2)
any
maintenance,
overhaul,
installation,
storage,
operation,
or
use,
which is
improper;
or
(3)
any
alteration,
modification,
or
repair
by
anyone
other than
CCS
or
its
authorized
representative.
THIS
WARRANTY
IS
EXPRESSLY
IN
LIEU
OF
ALL
OTHER
WARRANTIES
EXPRESSED
OR
IMPLIED
OR
STATUTORY INCLUDING
THE
WARRANTIES
OF
DESIGN,
MERCHANTABILITY,
OR
FITNESS
OR
SUITABILITY
FOR
USE OR
INTENDED
PURPOSE
AND
OF
ALL
OTHER
OBLIGATIONS
OR
LIABILITIES
OF
CCS.
To
any
extent
that
this
warranty
cannot
exclude
or
disclaim
implied
warranties,
such
warranties
are
limited
to
the
duration
of
this
express
warranty
or
to
any
shorter
time
permitted
by
law.
7

CCS
expressly
disclaims
any
and all
liability
arising
from the
use
and/or
operation
of
its
products
sold
in
any
and
all
applications
not
specifically
recommended,
tested,
or
certified
by
CCS,
in
writing.
With
respect
to
applications
not
specifically
recommended,
tested,
or
certified
by
CCS,
the
original
purchaser
acknowledges
that he
has
examined
the
products
to
which
this
warranty
attaches,
and
their
specifications
and
descriptions,
and
is
familiar with
the
operational
characteristics
thereof.
The
original
purchaser
has
not
relied
upon
the
judgement
or
any
representations
of
CCS
as
to
the
suitability
of
any
CCS
product
and
acknowledges
that
CCS
has
no
knowledge
of
the
intended
use
of
its
products.
CCS
EXPRESSLY
DISCLAIMS
ANY
LIABILITY
ARISING
FROM
THE
USE
AND/OR
OPERATION
OF ITS
PRODUCTS,
AND
SHALL
NOT
BE
LIABLE
FOR
ANY
CONSEQUENTIAL
OR
INCIDENTAL
OR
COLLATERAL
DAMAGES OR
INJURY
TO
PERSONS OR
PROPERTY.
CCS’s
obligations
under
this
warranty
are
conditioned
on
the
original
purchaser's
maintenance
of
explicit
records
which
will
accurately
reflect
operating
conditions
and
maintenance
preformed
on
CCS's
products
and
establish
the
nature
of
any
unsatisfactory
condition
of
CCS's
products.
CCS,
at
its
request,
shall
be
given
access
to
such
records
for
substantiating
warranty
claims.
No
action
may
be
brought
for
breach
of
any
express
or
implied
warranty
after
one
(1)
year
from
the
expiration
of
this
express
warranty's
applicable
warranty
period.
CCS
assumes
no
liability
for
any
events
which
may
arise
from
the
use
of
technical
information
on
the
application
of
its
products
supplied
by
CCS.
CCS
makes
no
warranty
whatsoever
in
respect
to
accessories
or
parts
not
supplied
by
CCS,
or
to
the
extent
that
any
defect
is
attributable
to
any
part
not
supplied
by
CCS.
CCS
neither
assumes
nor
authorizes
any
person
other than
a
duly
authorized officer
or
representative
to
assume
for
CCS
any
other
liability
or
extension
or
alteration
of
this
warranty
in
connection
with
the
sale
or
any
shipment
of
CCS's
products.
Any
such
assumption
of
liability
or
modification
of
warranty
must
be
in
writing
and
signed
by
such
duly
authorized officer
or
representative
to
be
enforceable.
These
warranties
apply
to
the
orginal
purchaser
only,
and
do
not
run
to
successors,
assigns,
or
subsequent
purchasers
or
owners:
AS
TO
ALL
PERSONS
OR
ENTITIES
OTHER
THAN THE
ORIGINAL
PURCHASER,
CCS
MAKES
NO
WARRANTIES
WHATSOEVER,
EXPRESS OR
IMPLIED
OR STATUTORY.
The
term
"original
purchaser"
as
used
in
this
warranty
shall
be
deemed
to
mean
only
that
person
to
whom its
product
is
originally
sold
by
CCS.
Unless
otherwise
agreed,
in
writing,
and
except
as
may
be
necessary
to
comply
with this
warranty,
CCS
reserves
the
right
to
make
changes
in
its
products
without
any
obligation
to
incorporate
such
changes
in
any
product
manufactured theretofore.
This
warranty
is
limited
to
the
terms
stated
herein.
CCS
disclaims
all
liability
for incidental
or
consequential
damages.
Some
states
do
not
allow
limitations
on
how
long
an
implied
warranty
lasts
and
some
do
not
allow
the
exclusion
or
limitation
of
incidental
or
consequential
damages
so
the above
limitations
and
exclusions
may
not
apply
to
you.
This
warranty
gives
you
specific
legal
rights,
and
you may
also have
other
rights
which
vary
from
state
to
state.
8