1-1.
SCOPE
This
ALTAIRrM8800b
Documentation
provides a general description
of
the various printed
circuit
cards
contained in the
ALTAIR
88OOb
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
88OOb
front panel.
De-
tailed
assembly instructions are
a1
so
provided.
1-2.
ARRANGEMENT
This
manual
contains five sections
as
follows:
1. Section I contains a general
description
of
the
ALTAIR
88OOb
computer
and
associated printed
circuit
cards.
2.
Section II contains information
on
the controls
and
indicators
which
are located
on
the
ALTAIR
88OOb
front panel.
3:
Section
III
contains a detailed
theory explanation of the
ALTAIR
88OO~
circuit
operation.
4.
Section
IV
contains trouble-
shooting information for the
ALTAIR
88OOb.
5.
Section Vcontains the detailed
assembly
instructions for the
ALTAIR
88OOb.
Apri
1,
1977
8800b
SECTION.
I
INTRODUCTION
1~3.
DESCRIPTION
The
ALTAIR
88OOb
computer (Figure
1-1)
is
a general purpose, byte-
oriented
machine
(8-bit
word).
It
uses a
common
1OO-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
88OOb
computer
has
78
basic
machine
lan-
guage
instructions
and
consists
of
a
power
supply board,
an
interface
board, a central processing unit
(CPU)
board,
and
a display/control
board.
1-4.
POWER
SUPPLY
BOARD
(Figure 1-2)
The
Power
Supply
Board
provides
two
of the three output voltages to the
ALTAIR,88OOb
computer
bus, a posi-
tive
and
negative
18
volts.
It
includes a bridge
rectifier
circuit
and
associated
filter
capacitors, a
1O-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
88OOb
bus.
It
also contains eight
parallel
data
lines
which
transfer
data to the
CPU
from
the Display/Control board.
Page
T-1
