Atari 800XL Service Manual

Procedure
t
.
Connect
the
computer
console
to TV
set
as
shown
in
owner’s
manual
2.
Turn
on
TV
set
3.
Press
and
hold
the
OPTION
key
as
the
computer
is
turned
on
until
the
Self
Test
menu
appears.
4.
The
Self
Test
Menu
displays
four
options:
*
Memory
«
Audiovisual
*
Keyboard
*
All
Test
Press
the
SELECT
key
to
move
the
selection
indicator
until
you
reach
the
desired
test
Press
the
START
key
to
begin
the
test.
CAUTION:
Self
Test
will
not
go Into
the
Attract
Mode.
Do not
leave
Self
Test
screens
on for
any
length
of
time
(
maximum
seven
minutes),
since
screen
burning
can
occur.
DESCRIPTION O
F SELF TESTS
MEMORY TEST
Purpose:
To
test
the
ROM
,
RAM
,
and
ANTIC
chips.
Format:
Two
long
bars
displayed
at the
top
of the
screen
represent
the
1
6K
Operating
System
ROM.
Below
them
are
48
blocks,
each
representing
1 K of
RAM.
The
remaining
1
6K
of RAM
is
available
only
with
certain
software
programs
and
is
not
tested
at
this
time.
When
either
ROM
or
RAM
is
being
tested,
the
corresponding
bar
segment
color
is white.
If
the
ROM
or
RAM
tests
good,
the
bar
color
changes
to li$it
green.
If
the
ROM
or
RAM
tests
defective,
the
color
changes
to
red.
Once
a
ROM
or
RAM
has
been
tested
and
found
defective
the
bar
or
specific
block
remains
red
and
the
memory
is
not
tested
again
on
subsequent
test
passes.
The
MEMORY
TEST
continues
testing
until
either
the
HELP
or
RESET
key
is
pressed.
NOTE:
If
RESET
is
used
to
exit
a test,
the
OS
will
return
to
BASIC
uot
the
Self
Test.
You
must
then
press
and
hold
OPTION
and
power
up the
console
as before.
24

Atari 800XL Specifications

General

Manufacturer	Atari
Type	Home computer
Release year	1983
CPU	MOS Technology 6502C
RAM	64 KB
ROM	24 KB
Operating System	Atari OS
CPU Speed	1.79 MHz (NTSC) / 1.77 MHz (PAL)
Graphics	ANTIC and GTIA chips
Display resolution	160×192 to 320×192 pixels
Sound	POKEY chip
Storage	Cassette tape, floppy disk
Ports	Serial, parallel, monitor, joystick ports