1-1.
SCOPE
This
ALTAI~M8800b
Documentation
provides ageneral description
of
the various printed
circuit
cards
contained in the
ALTAIR
8800b
and
detailed theory of
their
operation.
Included in the documentation
is
an
operator's guide
which
famili-
arizes the operator with the var-
ious switches
and
indicators
on
the
ALTAIR
8800b
front panel.
De-
tailed
assembly
instructions are
also provided.
1-2.
ARRANGEMENT
This
manual
contains five sections
as
follows:
1.
Section Icontains ageneral
description
of
the
ALTAIR
8800b
computer
and
associated printed
circuit
cards.
2.
Section II contains information
on
the controls
and
indicators
which
are located
on
the
ALTAIR
8800b
front panel.
3: Section
III
contains adetailed
theory explanation of the
ALTAIR
8800~
circuit
operation.
4.
Section
IV
contains trouble-
shooting information for the
ALTAIR
8800b.
5.
Section Vcontains the detailed
assembly
instructions for the
ALTAIR
8800b.
April,
1977
8S00b
SECTION.
I
INTRODUCTION
1~3.
DESCRIPTION
The
ALTAIR
8800b
computer
(Figure
1-1)
is
ageneral purpose, byte-
oriented
machine
(8-bit
word).
It
uses
a
common
lOO-pin
bus
struc-
ture
that
allows for expansion
of
either
standard or
custom
plug-in
modules.
It
supports
up
to
64K
of
directly
addressable
memory
and
can
address
256
separate input
and
output devices.
The
ALTAIR
8800b
computer
has
78
basic
machine
lan-
guage
instructions
and
consists
of
a
power
supply board,
an
interface
board, acentral processing
unit
(CPU)
board,
and
adisplay/control
board.
1-4.
POWER
SUPPLY
BOARD
(Figure 1-2)
The
Power
Supply
Board
provides
two
of the three output voltages to the
ALTAIR.8800b
computer
bus, aposi-
tive
and
negative
18
volts.
It
includes abridge
rectifier
circuit
and
associated
filter
capacitors, a
lO-pin terminal block connector,
and
the regulating
transistors
for
the positive
and
negative
18
volt
supplies.
1-5.
INTERFACE
BOARD
(Figure 1-3)
The
Interface
Board
buffers
all
signals
between
the display/control
board
and
the
ALTAIR
8800b
bus.
It
also contains eight parallel data
lines
which
transfer
data to the
CPU
from
the Display/Control board.
Page
T-1
