North Star ADVANTAGE 8/16 User manual

; NorthStar
North Star ADVANTAGE 8/16
Service Manual

NorthStar
North Star Computers, Inc.
14440 Catalina St., San Leandro, CA 94577 USA
[phone] TWX/Telex [phone]
North Star ADVANTAGE 8/16
Service Manual
Z-80A® is a registered trademark of Zilog, Inc.
8088-2® is a registered trademark of Intel Corporation
CP/M® is a registered trademark of Digital Research, Inc.
MSDOS™ is a trademark of Microsoft, Inc.
Copyright ©1983, by North Star Computers, Inc.
All Rights Reserved

TABLE OF CONTENTS
Section
1.0
2.0
5.0
General Data .....«. -@
1.1 Technical Manual Overview
1.2 System Maintenance... .
1.3 System Configuration...
1.4 Glossary of Terms ....
Repair Data . ....+ +e -«
Safety Precautions. .
Setting the ADV-16 CPU
Parts Identification ...
Mini-Jump
Connector
Removing the ADV-16 CPU Circuit Board ..
Removing ADV-16 64K RAM Circuit Boards. .
Removing the ADV-16 Power Boost Module. .
Adjusting the ADV-16 Power Boost Module .
3.1 ADV-16 CPU Circuit Board Line Drawing ..
3.2 ADV-16 CPU Assembly Parts List . .... .
3.3 ADV-16 64K RAM Circuit Board Line Drawing
3.4 ADV-16 64K RAM Assembly Parts List ....
3.5 ADV-16 Power Boost Module Circuit Board
Line Prawing «2 s* ss @ 6% 4 8
3.6 ADV-16 Power Boost Module Assembly Parts
Troubleshooting ..... .
4.1 Test Section #1 ...
4.2 Test Section #2 ...
4.3 Test Section #3 ...
4.4 Test Section #4 ...
Plug/Jack List ......
5.1 ADV-16 CPU Circuit
Board « « « «
5.2 ADV-16 64K RAM Circuit Board. .
5.3 ADV-16 Power Boost Module ...
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Table of Contents

TABLE
OF
CONTENTS
(continued)
Section
6.0 Principles of Operation .
6.1 Overview ......
6.2 CPU Logic s«..« © «
6.3 Memory Logic ....
6.4 Communications Logic
6.5 Timing Logic ....
6.6 ADV-16 Power Boost M
6.7
6.8 2Z80A Address/Data Bi
6.9 ADV-16 CPU Schematic
6.10 ADV-16 64K RAM Schem
6.11 ADV-16 Power Boost M
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ii Table of Contents

INTRODUCTION
CHAPTER
1
ata
ttt
This
service
manual
is
an
addendum
to
the
North
Star
ADVANTAGE
Technical
Manual.
It
contains
the
information
necessary
for
maintenance
of
the
North
Star
ADVANTAGE
8/16.
The
North
Star
ADVANTAGE
8/16
is
a
modification
of
the
North
Star
ADVANTAGE
microcomputer.
The
modification
is
an
upgrade
that
includes
installation
of
a
circuit
board
containing
a
16-bit
Intel
8088-2
microprocessor,
an
8
Mhz
clock,
and
64K
of
RAM
with
supporting
input/output
logic.
Additional
plug-in
64K
RAM
boards
are
available
to
make
up
a
full
256K
memory
storage.
1-1 General Data

TECHNICAL
MANUAL
OVERVIEW
Introducti
Chapter Title
ue General
Data
2 Repair
Data
3 Parts
Identifi-
cation
4 Trouble-
shooting
5 Plug/Jack
Lists
6 Principles
of Operation
Specifica-
tions
1.1
on
The
North
Star
ADVANTAGE
8/16
Technical
Manual
is
divided
into
six
chapters.
Contents
This
chapter
contains
information
about
use
of
the
manual,
configuration
charts,
and
system
maintenance.
This
chapter
contains
procedures
for
removing
and
adjusting
parts.
This
chapter
contains
circuit
board
illustrations
and
lists
of
part
numbers.
This
chapter
contains
troubleshooting
Strategies
and
diagnostic
procedures.
This
chapter
contains
drawings
of
plugs
and
jacks
that
are
unique
to
the
North
Star
ADVANTAGE
8/16.
Pin
numbers
for
the
plugs/jacks
are
labeled,
and
the
Signals
or
voltages
that
appear
on
the
pins
are
identified.
This chapter contains a discussion of
the operation of the the ADV-16 CPU and
ADV-16 64K RAM circuit boards and the
ADV-16 Power Boost Module. Block
diagrams
and
full
schematics
show
functional areas and relationships.
Specifications for the North Star ADVANTAGE 8/16
are identical to those of the standard North Star
ADVANTAGE,
Technical Manual
Refer to the North Star ADVANTAGE
for complete machine
specifications,
General Data

SYSTEM
MAINTENANCE
.
1.2
ee
Procedures
Service
Philosophy
Addition
of
the
ADV-16
CPU
circuit
board,
the
ADV-
16
64K
RAM
circuit
board,
and
the
ADV-16
Power
Boost
Module
has
negligible
effect
on
the
physical
or
electrical
environments
of
the
North
Star
ADVANTAGE
system.
Maintenance
should
proceed
with
troubleshooting
techniques
similar
to
those
used
on
the
standard
North
Star
ADVANTAGE.
Product reliability is a feature of every North
Star product, and rigid manufacturing quality
control is used to achieve that goal in the North
Star ADVANTAGE 8/16. Long term reliability should
be the goal of the technician who services this
system. This can be achieved if service is
preventive as well as restorative. Attention must
be paid to each of the major subassemblies during
repair, and this should include examination,
cleaning, and adjusting:
fe) the keyboard,
° the base assembly including the main board
and power supply,
fo) the input/output circuit boards,
the disk drive assemblies,
and the video display assembly including the
control circuit board and cathode ray tube.
lomo)
1-3 General Data

SYSTEM
CONFIGURATION
1.3
Description
Early
Version
Later
Version
Configur-
ation
Identifi-
cation
There are two different configurations of the
North Star ADVANTAGE 8/16 microcomputer. Although
the differences are not apparent to the computer
Operator, a technician who services the system
must be aware of both versions.
North Star ADVANTAGE 8/16 computers manufactured
prior to December 1982 contain power supplies that
are able to support any combination of PIO and SIO
circuit boards as well as a hard disk drive and
hard disk controller circuit board.
However, adding the ADV-16 CPU and plug-in ADV-16
64K RAM circuit boards to the earlier North Star
ADVANTAGE requires that the existing power supply
be supplemented by the ADV-16 Power Boost Module.
Power for the ADV-16 CPU and 64K RAM circuit
boards is routed directly from the output of the
module.
North Star ADVANTAGE 8/16 computers manufactured
after December 1982 contain power supplies that
are able to support any combination of PIO and SIO
circuit boards, a hard disk drive and hard disk
controller circuit board, an ADV-16 CPU circuit
board, and up to three ADV-16 64K RAM circuit
boards. Power for the ADV-16 CPU and 64K RAM
circuit boards is routed directly from the host
power supply via the system I/O bus.
The system configurations can be differentiated by
looking at the North Star ADVANTAGE serial number
plate. The earlier version has two smaller plates
that are silver; the recent version has a single
larger plate that is beige.
TM 14440 Catalina st = leanare — Model
NorthStar [phone] TWx/lelex (910) 366 700! North Star ADVANTAGE
Made in U.S.A.
Seer cal
ADVANTAGE Ss
ay ca
ay be necessary t ec
. Made
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1-4 General Data