Atari 400 Field Service Manual

SECTION
7
800
DIAGNOSTIC FLOWCHART
The
Diagnostic
Flowchart
is
intended to be
easy to
use and
the primary
aid when
troubleshooting
the ATARI
800
Computer
Console. Follow
the prompts
in the
order
presented. When
a question
is asked,
follow
the line
from that
box which
best
applies
to
the unit's
situation.
The
flowchart
leaves
little to
chance,
it tells
you when
to
perform
a specific
test and when
to replace
components.
Swap
Out
Procedure
At many
places in
the diagnostic
flowchart,
a box
tells
you to
"swap-out"
a chip or
a
number
of chips
in
a particular
order.
The
"swap-out"
instruction
means
that
you
should
replace
the
indicated
components
(one
at a
time) with
a known
good
component
of
the
same
type. The
800
should then
be
tested with
the
new,
known-good
component
in
place
to
see whether
the
"swap-out"
solved the
problem
being
checked. If
the swap-
out
did not
fix the
problem,
the
known-good
component
should
be
removed,
and
the
original
component
reinserted.
In
this
way,
you avoid
needlessly
replacing
good
components-
°
CAUTION:
Extreme
care
should
be
taken
when
handling
the
integrated
circuit
chips.
They
are
all
v«r]t
sensitive
to static
electricity
and
can easily
be
damaged
by
careless
handling.
Al2s^
keep
the
chips
in
their
plastic
carrier
tubes
or
on
conductive
foam
when
not
handling
them.
Make
certain
you
are well
grounded
when
handling
the
chips.
Atari
strongly
recommends
that
you
wear
a
conductive
grounding band
(which
ties from
your
arm
to
ground)
when
handling
the
chips.
The
chips
are also
susceptible
to
damage
from stress
when
being
removed
from
or
inserted
into
the
sockets.
Always
use a
chip-puller
when
removing
the
chips.
Do not
pry
the
chip
out
with
a
screwdriver
or
any other
tooL
Failure
to
follow
the
above
guidelines
results
in unusally
high
chip
faUure
rates
and
extra
expense-
ATARI
Home
Computer
7-1

Atari 400 Specifications

General

Manufacturer	Atari
Model	400
Type	Home Computer
Release Year	1979
CPU	MOS Technology 6502
CPU Speed	1.79 MHz
ROM	10 KB
Operating System	Atari OS
Keyboard	Membrane keyboard
RAM	8 KB (expandable to 48 KB)
Graphics	ANTIC and GTIA chips
Sound	4 channels
Display	RF output for connection to TV
Storage	Optional cassette tape drive or floppy disk drive
Ports	Cartridge
Display Resolution	320x192 (16 colors)