North star Zpb-a User manual

NORTH

STAR

*

COMPUTERS,

INc.

2547 Ninth

Street·

Berkeley, California 94710 • (415) 549-0858

North

Star

Z80A PROCESSOR

BOARD

ZPB-A

Contents

Cautions

• . .

.•

....•.••

2

Introduction

.

..

•....•••

3

Limited

Warranty

. • . . . . . • . 4

Out

of

Warranty

Repair

. . . . . • • • 4

ZBP-A

Parts

List

. • • • • • .

•.

5

PROM

Option

Parts

List

.

•••

6

Assembly

Information

. • . . . • • . .

..

7

Figure

lA:

Component

Identification

.

10

ZPB

Assembly

• .

•.

...••....

11

ZBP

Board

Checkout

•

.•...•...

15

PROM

Option

Assembly

and

Checkout

. . . . 20

Configuration

Options

.•..

. .

•.

21

Theory

of

Operation

• . . . • . . • • 24

Appendix

1:

Pulse

Signal

Detection

..•.

28

Appendix

2:

S-100

Bus

Signals

.

.•

. 29

Assembly

Figures

. . . • . . . • . . • • . 30

Schematic

Drawings

. • . . .

..

...

31

Copyright

1977,

North

Star

Computers,

Inc.

REVISION 3

CAUTIONS

1.

Correct

this

document

from

the

errata

sheets,

if

any,

before

doing

anything

else.

2.

Building

this

product

from

a

kit

is

a

complex,

demanding

project.

It

should

not

be

attempted

without

prior

kit

building

experience.

3.

Do

NOT

insert

or

remove

the

ZPB

from

the

computer

while

the

power

is

turned

on.

Note

that

the

power

is

not

completely

off

until

the

capacitors

have

discharged,

several

seconds

after

turning

of

the

power

switch.

4.

Do

NOT

insert

or

remove

IC's

from

the

board

while

the

power

is

turned

on.

5.

Be

sure

each

5

volt

regulator

is

generating

5

volt

outp~t

voltage

before

installing

any

IC's.

6.

Be

careful

to

insert

all

IC's

in

correct

positions

and

with

correct

orientation.

Be

sure

all

IC

pins

are

correctly

inserted

into

the

socket

holes

and

are

not

bent

under

the

IC

and

are

not

outside

the

socket.

7.

Carefully

observe

the

anti-static

handling

procedure

for

the

static

sensitive

devices

(these

are

the

Z80A

and

the

2708

PROM

in

the

PROM

option).

The

procedure

is

described

in

the

Assembly

Information

section

of

this

manual.

North

Star

Z80A PROCESSOR

BOARD

2

INTRODUCTION

The

North

Star

Computers

Z80A

Processor

Board

(ZPB)

provides

Z80

microprocessor

capability

on

the

S-100

bus.

The

use

of

the

Z80A

chip

allows

full

speed

4MHz

operation

as

a

standard

feature.

The

ZPB

can

be

used

in

any

standard

S-100

bus

computer

and

will

operate

in

conjunction

with

nearly

all

other

S-100

bus

boards.

However,

the

ZPB

has

been

specifically

designed

to

integrate

into

the

North

Star

Computers

HORIZON

computer

system.

In

addition

to

the

Z80A

microprocessor

and

support

logic

to

interface

to

the

standard

S-100

bus,

the

ZPB

contains

the

following

features

and

options:

1.

AUTO-JUMP

feature

that

will

'cause

an

automatic

jump

to

any

address

at

power-on

or

reset.

2.

VECTORED

INTERRUPTS.

ZPB

logic

will

respond

to

eight

levels

of

interrupt

requests,

determine

the

highest

priority

request

pending

and

generate

the

appropriate

RST

instruction.

The

logic

may

be

disabled

to

allow

the

function

to

be

performed

on

another

board.

3.

FRONT

PANEL

INTERFACE

for

direct

connection

to

IMSAI

and

other

similar

front

panels.

4.

ADDRESS

MIRROR

feature

to

simulate

the

input/output

characteristics

of

the

8080

microprocessor.

This

feature

maintains

compatibility

with

some

S-100

bus

peripheral

boards.

Address

mirroring

may

be

disabled

to

allow

use

of

the

more

powerful

Z80

protocol.

5.

PROM

OPTION. lK

of

2708

type

erasable

PROM

can

be

added

to

the

ZPB.

This

allows

configuration

of

systems

that

requ~re

resident

monitor

and

bootstrap

programs.

If

you

have

purchased

t~e

ZPB

as

a

kit,

first

skim

this

entire

manual.

Before

beginning

assembly,

carefully

read

the

Assembly

Information

section.

Whether

you

purchased

the

ZPB

as

a

kit

or

assembled,

read

the

Configuration

section

before

attempting

to

use

the

ZPB.

Note

that

a

Z80

Technical

Manual

has

been

included

to

fully

describe

the

operation

of

the

Z80A.

3

North

Star

Z80A

PROCESSOR

BOARD

LIMITED

WARRANTY

North

Star

Computers,

Inc.

warrants

the

electrical

and

mechanical

parts

and

workmanship

of

this

product

to

be

free

of

defects

for

a

period

of

90

days

from

date

of

purchase.

If

such

defects

occur,

North

Star

Computers,

Inc.

will

repair

the

defect

at

no

cost

to

the

purchaser.

This

warranty

does

not

extend

to

defects

resulting

from

improper

use

or

assembly

by

purchaser,

nor

does

it

cover

transportation

to

the

factory.

Also,

the

warranty

is

invalid

if

all

instruction~

included

in

the

accompanying

documentation

are

not

carefully

followed.

Should

a

unit

returned

for

warranty

repair

be

deemed

by

North

Star

Computers,

Inc.

to

be

defective

due

to

purchaser's

action,

then

a

repair

charge

not

to

exceed

$30

without

purchaser's

consent

will

be

assessed.

ANY

UNIT

OR

PART

RETURNED

FOR

WARRANTY

REPAIR

MUST

BE

ACCOMPANIED

BY

A

COPY

OF

THE

ORIGINAL

SALES

RECEIPT.

This

warranty

applies

to

units

located

outside

the

united

States

of

America

only

if

all

costs

and

arrangements

for

transportation

of

the

product

to

and

from

the

factory

are

borne

entirely

by

the

customer.

This

warranty

is

made

in

lieu

of

all

other

warranties,

expressed

or

implied,

and

is

limited

to

the

repair

or

replacement

of

the

product.

No

warranty,

expressed

or

implied,

is

extended

concerning

the

completeness,

correctness,

or

suitability

of

the

North

Star

equipment

for

any

particular

application.

There

are

no

warranties

which

extend

beyond

those

expressly

stated

herein.

OUT

OF

WARRANTY

REPAIR

If

your

unit

is

out

of

warranty

and you

are

unsuccessful

at

diagnosing

or

repairing

the

problem,

out-of-warranty

service

may

be

arranged

with

a

local

dealer

or

other

experienced

local

computer

technician.

Alternatively,

any

North

Star

products

may

be

shipped

PREPAID

to

the

North

Star

address

with

a

clear

written

description

of

the

problem.

Include

as

many

details

as

possible

about

the

problem

and

about

your

system

configuration.

Your

unit

will

be

returned,

C.O.D.,

within

30

days

after

receipt

by

North

Star.

Out-of-warranty

repair

service

is

billed

at

the

rate

of

$25.00

per

hour.

If

you

wish

to

place

an

upper

limit

on

the

amount

of

time

spent

on

your

unit,

mention

this

in

the

written

description.

North

Star

Z80A

PROCESSOR

BOARD

4

ZPB-A

PARTS

LIST

1

ZPB

Manual

1 . Z8e

Technical

Manual

1

ZPB

printed

circuit

board,

5"

x

10"

1

40-pin

IC

socket

7

20-pin

IC

sockets

14

16~pin

IC

sockets

14

14-pin

IC

sockets

1

16-pin

DIP

header

1 1N4148

diode

2 5

volt

regulators,

7805

or

340T-5

2

heat

sinks,

6107B-14

1

crystal,

8MHz

2

6-32x3/8"

machine

sctews

2

#6

lock

washers

2

6-3.2

nuts

Integrated

Circuits

3 74LS00 1

74LS132

2 74LS02 1 74LS.148

1

74LSe3

3

74LS175

2 74LS04 7

74LS241

1 74LSeS 2

74LS257

1 74LS14 1

7404

1

74LS32

3

74367

1 74LS74 1 ST97

2

74LS75

. 1

ZS0A

Resistors

1

1e0

ohm

(brown-b1ack-brown)

1

33~

6hm

(orange-orange~brown)

2

'470

ohm

(ye11ow-vio1et-brown)

11

1K

ohm

(btown-b1ack-red)

1 1eK ohm

(brown-b1ack-orange)

4

1K

ohm

networks,

Part

No.

10-9-1-RIK

1

2.2K

ohm

network,

Part

No.

1e-9-1-R2.2k

Capacitors

1

19

2

1

5

33pf

470pf

.e47uf

6.8uf

39uf

1eeuf

dipped

mica

(may

be

marked

"330J03")

dipped

mica

ceramic

disc

dipped

tantalum

dipped

tantalum

electrolytic

North

Star

Z8eA

PROCESSOR

BOARD

,

PROM

OPTION

PARTS

LIST

2

74LS136

IC

1

2708

EPROM

1

+12

volt

regulator,

78L12

1

-5

volt

regulator,

79L05

1

24-pin

IC

socket

3

14-pin

IC

sockets

1

14-pin

DIP

header

1

lK

resistor

(brown-black-red)

1

3.9K

resistor

(orange-white-red)

1

3.9K

resistor

network,

Part

No.

10-9-1-R3.9K

4

2.2uf

dipped

tantalum

capacitors

North

Star

Z80A

PROCESSOR

BOARD

6

ASSEMBLY

INFORMATION

Read

completely

through

each

section

before

beginning

the

first

instruction

step

of

that

section.

Perform

all

operations

in

the

sequence

indicated.

Read

each

step

entirely,

including

any

notes

that

accompany

the

step,

before

beginning

to

follow

the

s~ep.

WORK

AREA

AND

TOOLS

Start

with

a

clean,

well-lit

and

well-ventilated

area

to

work.

The

area

should

be

large

enough

to

accommodate

the

kit,

tools,

parts

and

assembly

instructions.

Suggested

tools

are:

screwdrivers,

needle-nose

pliers,

diagonal

cutters,

soldering

iron,

solder,

and

masking

tape.

A number

of

tests

will

require

using

a

VOM

(ohmmeter-voltmeter),

or

VTVM.

Also

highly

desirable,

but

not

necessary,

are

an

IC

inserter,

a

screw-holding

screwdriver,

an

oscilloscope

or

logic

probe,

and

an

extender

card.

[Note

that

if

you

do

not

have

an

oscilloscope

or

logic

probe,

waveforms

can

be

detected

by

one

of

the

procedures

described

in

Appendix

1.]

SOLDERING

TIPS

For

best

results

use

a 15

to

25

watt

soldering

iron

or

an

iron

with

a

temperature

controlled

tip

(approximately

700

degrees).

The

tip

should

be no

wider

than

the

solder

pads

on

the

printed

circuit

board.

Use

only

a

fine

gauge

rosin

core

solder

(60/40

or

63/37).

Do

NOT

use

acid

core

solder

as

this

can

severely

damage

a

printed

circuit

board.

When

soldering,

keep

the

soldering

iron

tip

on

the

pad

just

long

enough

for

the

solder

to

completely

flow.

If

the

solder

does

not

draw

up

the

wire

then

more

solder

is

required.

Do

not

use

so

much

solder

that

it

overflows

the

pad.

If

a

solidified

joint

is

not

shiny,

it

may

be

a

cold

solder

joint

and

should

be

remelted.

The

soldering

iron

tip

should

be

cleaned

frequently

by

wiping

on a damp

sponge

When

you

have

completed

assembly

of

a

board,

inspect

it

for

unintended

solder

connections

or

"bridges",

as

well

as

unsoldered

leads.

After

soldering,

it

is

recommended

that

the

rosin

flux

be

removed

from

the

board

using

flux

remover,

FREON

or

paint-thinner

type

solvent.

This

will

make

looking

for

soldering

problems

easier

and

give

the

board

a

clean,

professional

appearance.

IC

SOCKET

INSTALLATION

Integrated

circuit

(IC)

sockets

can

be

installed

by

first

inserting

them

into

the

printed

circuit

board,

then

placing

another

flat

board

over

the

IC

sockets

and

finally

turning

over

this

sandwich.

Be

sure

that

each

IC

socket

is

inserted

into

the

proper

location

and

is

oriented

such

that

I

of

the

socket

corresponds

to

the

I

indication

on

the

PC

board

layout

legend.

(Refer

to

figure

IA

to

identify

I on

an

IC

socket.)

To

solder

IC

sockets,

first

solder

just

two

opposite

corner

pins

7

North

Star

Z80A

PROCESSOR

BOARD

for

all

sockets

being

installed.

Then

remelt

the

corner

connections

while

applying

pressure

down

on

the

board.

This

will

remove

any

gaps

that

may

be

present

between

the

IC

sockets

and

the

PC

board.

Finally,

solder

the

remaining

pins

of

the

IC

sockets.

.

DIP

HEADER

SOLDERING

When

making

jumper

conn~ctions

on

a DIP

header,

solder

resistor

or

capacitor

lead

snippings

between

the

leads

to

be

connected.

When

more

than

two

pins

are

to

be

connected

together,

bend

a

single

wire

so

that

it

routes

to

each

pin,

and

solder

each

once.

Insert

the

header

in

an

IC

socket

on

a

PC

board

to

hold

it

during

soldering.

Overheating

the

pins

with

the

soldering

iron

will

melt

the

plastic

of

the

header.

If

there

are

multiple

jumpers

on

a

header,

make

sure

that

no

unintended

connections

are

made

by

carefully

routing

the

jumpers,

or

by

insulating

each

jumper

with

some

wire

insulation.

RESIsTOR

AND

CAPACITOR

INSTALLATION

To

install

resistors

or

capacitors,

first

make

right

angle

bends

in

the

leads

to

fit

the

PC

board

hole

spacing.

(Some

capacitor

leads

are

already

appropriately

spaced

and

do

not

need

bending.)

Then

insert

the

leads

as

far

as

possible

through

the

correct

holes

in

the

PC

board

and

spread

the

leads

slightly

on

the

solder

side

of

the

board

to

keep

the

part

in

place.

After

a

group

of

resistors

or

capacitors

has

been

inserted,

then

solder

the

leads

on

the

solder

side

of

the

board

and

snip

off

the

excess

leads

as

close

to

the

board

as

possible.

Use

caution

to

avoid

eye

injury

from

flying

bits

of

wire.

Save

the

lead

clippings

for

later

use

in

making

jumper

connections.

PRINTED

CIRCUIT

BOARD

LAYOUT

The

white

component

layout

legend

is

printed

on

the

component

side

of

a

printed

circuit

(PC)

board.

All

components

are

inserted

from

this

side

(component

side)

and

soldered

on

the

other

side

(solder

side).

Locations

on

the

PC

board

are

identified

by

two-character

codes

as

marked

on

the

board:

a

digit

followed

by

a

letter

indicating

the

horizontal

and

vertical

coordinates

of

the

location.

Note

that

in

North

Star

kits,

IC's

can

be

found

on

styrene

pads

in

positions

corresponding

to

their

intended

locations

on

the

PC

board.

numbering

conventions

for

the

S-100

edge

pins

are

as

follows:

When

viewing

the

component

side

of

the

board

(with

the

edge

facing

down),

pins

1,2,

•••

, 50

range

from

left

to

right.

When

viewing

the

solder

side

of

the

board,

pins

100,

99,

•••

, 51

range

from

left

to

right.

North

Star

Z80A

PROCESSOR

BOARD

8

MOS

INTEGRATED

CIRCUIT

HANDLING

Some

North

Star

PC

boards

use

some MOS-type

IC's.

These

parts

are

identified

as

such

in

the

instructions.

MOS

devices

can

be

damaged

by

static

electricity

discharge,

so

special

handling

is

necessary

to

protect

them.

Handle

MOS

devices

as

little

as

possible

and

avoid

touching

the

pins.

Place

the

conductive

foam

or

tube

which

contains

the

MOS

device

onto

the

PC

board

before

removing

the

device

from

the

foam

or

~ube.

Also,

be

sure

both

hands

are

touching

the

foam

or

tube

when

the

device

is

removed

from

the

foam

or

tube.

Once a

MOS

device

has

been

installed

in

a

PC

board,

handle

the

board

as

little

as

possible.

Of

course,

never

insert

or

remove

any

IC

while

power

is

applied

to

the

board,

and

never

remove

or

insert

a

PC

board

while

power

is

applied

to

the

motherboard.

9

North

Star

Z80A

PROCESSOR

BOARD

c:::=======t;t;

100

MFD

)):======::=::3

positive (+) lead

\};....

-

Transistor and

Regulator (To-92)

Quick-Connect

Lug

Axial Lead

Electrolytic Capacitor

EDD)

Resistor

Ceramic

Disc

Capacitor

Integrated Circuit (lC)

Dipped

Mylar

Capacitor

IC Socket

Dipped

Mica

Capacitor

Figure

1A_

Identification and orientation

of

components.

Resistor Network

Regulator (To-220)

Dipped

Tantalum

Capacitor

positive

(+) lead

DIP

Header

ZPB

ASSEMBLY

Before

beginning

assembly

of

the

ZPB,

first

check

that

you

have

all

the

parts

listed

in

the

parts

list.

Note

that

in

the

following

instructions,

"left"

and

"right"

refer

to

those

directions

when

viewing

the

component

side

of

the

PC

.

board

with

the

100-pin

edge

facing

down.

Zl.

Using

an

ohmmeter,

check

for

open

circuits

between

the

pair

of

solder

pads

for

each

of

the

following

seven

capacitor

locations:

C22,

C23,

C25, C26,

C27, C28,

and

C29.

If

any

shorts

are

found,

locate

and

correct

the

problem

or

return

the

PC

board

for

replacement.

Insert

and

solder

the

40-pin

IC

socket

at

location

3C,

following

the

procedure

given

in

the

Assembly

Information

section.

~z~':

Insert

and

solder

the

seven

20-pin

IC

sockets

with

correct

oJ'.ientation.

-'~nsert

and

solder

a

16-pin

IC

socket

at

location

IG.

Note

~.

~hat

this

socket

has

reverse

orientation

from

all

the

others,

with

1

in

t'he

upper

right

corner~

L-z

6.

11

Insert

and

solder

the

remaining

thirteen

16-pin

sockets

with

correct

orientation.

Insert

and

solder

the

fourteen

14-pin

sockets

with

correct

orientation.

Do

not

install

sockets

in

locations

5C, 5D,

and

5E

(inside

dashed

line)

unless

you

are

assembling

the

PROM

option

at

this

time.

Insert

and

solder

the

five'single-in-line

(SIP)

resistor

networks

labeled

RNl, RN2,

RN4,

RN5,

and

RN6

on

the

layout

legend.

RN6

is

a 2.2K

ohm

network

and

the

remaining

four

are

lK

ohm

networks.'

RN3

is

part

of

the

PROM

option.

Orient

each

SIP

so

the

end

marked

with

a

"1"

(sometimes

this

end

has

a

beveled

corner)

corresponds

to

the

end

marked

with

a

dot

on

the

layout

legend.

Insert

and

solder

the

following

sixteen

resistors.

Refer

to

the

Assembly

Information

section

for

resistor

installation

procedures.

Resistor

Value

Color-code

Location

(~)

Rl 470

ohm

yellow-violet-brown

IF

North

Star

Z80A

PROCESSOR

BOARD

r/R2

4713

ohm

yellow-violet-brown

IF

(~

R3

IK

ohm

brown-black-red

2E

(.

,RS IK

ohm

brown-black-red

5G

(t

R6

lK

ohm

brown-black-red

4F

__

(~

R7

3313

ohm

orange-orange-brown

4C

( )

R8

IK

ohm

brown-black-red

6B

(tV'R9

IK

ohm

brown-black-red

6B

(

RII

lK

ohm

brown-black-red

4G

(vi

Rl2

IK

ohm

brown-black-red

7C

(v(

Rl3

IK

ohm

brown-black-red

7A

(/toy

Rl4

lK

ohm

brown-black-red

7A

(J

Rl5

lK

ohm

brown-black-red

SF

~(

>.

Rl6 10K

ohm

brown-black-orange

8G

(v')

Rl7

100

ohm

brown-black-brown

8G

(Vy

R18

IK

ohm

brown-black-red

8G

J~9.

Insert

and

solder

the

1N4148

diode

at

location

8G. The

end

of

the

diode

marked

with

a

band

is

the

cathode

end

and

should

be

oriented

toward

the

top

of

the

board.

l./Z10.

Insert

and

solder

the

100uf

electrolytic

capacitor'

(C29)

located

near

8A. The

positive

end

(marked

with

a "+"

or

a

red

dot)

should

be

oriented

toward

the

right

as

indic'ated

on

the

layout

legend.

Some

capacitors

mark

the

neg9tive

end

with

a

"-"

instead

of

the

positive

end.

~3.

Insert

and

Bolder

the

39uf

tantalum

capacitor

(C21)

near

location

7G.

Be

sure

to

orient

the

capacitor

so

that

the

lead

marked

with

a "+"

is

inserted

through

the

hole

marked

with

a

"+".

Insert

and

solder

the

two

6.8uf

tantalum

capacitors

(C22

and

,C23)

at

locations

8F

and

8G.

Be

sure

to

orient

the

capacitors

so

that

the

lead

marked

with

a "+"

is

inserted

through

the

hole

marked

with

a

"+".

Insert

and

solder

the

470pf

dipped

mica

capacitor

(CI)

at

location

IF.

Some

470pf

capacitors

are

marked

"47IJO".

L/~I4.

Insert

and

solder

the

33pf

dipped

mica

capacitor

(CS)

at

location

2F. Some

33pf

capacitors

are

marked

"330J03".

ZIS.

Insert

and

solder

the

nineteen

ceramic

disc

bypass

capacitors

in

locations

marked

with

an

asterisk

on

the

layout'legend.

rvZ"16.

Insert

and

solder

the

BMHz

crystal

at

location

IF.

Make

right

angle

bends

in

the

two

leads

so

the

crystal

will

lie

parallel

with

the

PC

board.

To

hold

the

crystal

package

in

place,

use

a

piece

of

snipped

resistor

lead

to

solder

the

top

of

the

crystal

package

to

the

corresponding

hole

in

the

board.

A

little

space

should

be

left

between

the

crystal

and

the

PC

board

to

avoid

the

possibility

of

shorts.

North

Star

Z80A

PROCESSOR

BOARD

12

t;tls.

,.

l

\)19.

I

l'

1

/Z20.

V

Z2l.

NOTE:

The

8MHz

crystal

is

used

for

4MHz

operation

of

the

processor.

If

2MHz

operation

is

desired,

then

a

4MHz

crystal

(not

supplied)

should

be

used.

See

the

Configuration

section

for

details.

Recheck

the

circuits

between

the

capacitor

leads

as

in

step

Zl

and

make

sure

they

are

still

open

circuits.

Note

that'

the

capacitors

which

have

been

installed

may

cause

the

ohmmeter

needle

to

jump when

first

contact

is

made

but

the

indication

should

rapidly

return

to

a

high

resistance.

Insert

and

solder

the

two

5-volt

regulators

(Q3

and

Q4).

These

parts

will

be

marked

"7805"

or

1'340T-5".

Bend down

the

three

leads

of

the

regulator

90

degrees

so

that

the

leads

go

into

the

correct

holes

while

the

machine

screw

holes

lineup.

Install

the

heat

sink

and

regulator

so

that

the

following

sequence

results

from

bottom

to

top:

6-32

machine

screw

head,

PC

bo?rd,

heat

sink,

regulator,

lock

washer,

and

nut.

Finally,

make

sure

the

leads

do

not

touch

each

other

or

the

heat

sinks

and

then

tighten

the

machine

screw

and

solder

the

regulator

leads.

NOTE:

Heat

sink

grease

may

be

used

though

it

is

not

generally

needed.

Tightening

the

bolts

too

tight

can

crack

the

PC

board.

with

the

computer

power

off,

plug

the

partially

assembled

board

into

the

motherboard.

Then

turn

on

the

power.

with

a

DC

volt

meter

check

that

both

regulators

are

generating

5

volts

output.

These

voltages

can

be

measured

across

the

pins

of

C22

and

C23.

Wait

a few

minutes

and

measure

again.

The

regulators

should

not

get

very

hot

in

this

configuration.

However,

with

all

parts

installed

it

is

normal

for

the

regulator

to

feel

quite

hot

to

the

touch.

Remember

to

turn

off

the

power

before

removing

the

board.

Construct

a

l6-pin

DIP

header

with

jumpers

set

up

for

a

starting

address

of

E800

hex.,

This

is

the

standard

HORIZON

starting

address.

If

some

other

starting

address

is

desired,

change

the

header

after

completing

the

checkout

instructions.

See

figure

lZ

for

the

details

of

the

header

configuration.

Refer

to

the

Assembly

Information

section

for

header

construction

procedures.

Plug

the

completed

header

into

location

2E

(the

POJ

ADDRESS

socket)

with

the

correct

orientation.

Insert

,the

33

integrated

circuits

(all

except

the

Z80A

chip).

Be

sure

that

all

IC's

have

1

oriented

to

the

bottom

left

corner.

Do

not

insert

any

IC's

inside

the

area

for

the

PROM

option

(outlined

with

a

dashed

line).

Z22.

Recheck

the

regulator

output

voltages

as

in

step

Z19.

13

North

Star

Z80A

PROCESSOR

BOARD

Z23.

Remove

the

PC

board

from

the

computer

and

then

plug

in

the

Z80A

chip

with

correct

orientation.

Refer

to

the

Assembly

Information

section

for

MOS

device

handling

procedures.

Z24.

Inspect

the

board

in

a

good

light

to

insure

that:

A.

all

solder

joints

are

good,

i.e.

there

are

no

bridges

of

solder

beween

adjacent

solder

joints,

no

unsoldered

joints,

and

no

cold

solder

joints

indicated

by

a

dull

finish

on

the

solder.

B.

all

IC

pins

are

in

the

IC

socket

holes,

not

outside

the

socket

and

not

folded

under

the

chip.

Pins

folded

under

can

often

be

detected

by

sighting

down

a

row

of

chips

to

see

if

there

is

any

blockage

of

light

under

the

chips.

C.

all

parts

are

installed

in

the

correct

locations

with

the

correct

orientation.

The

ZPB

is

now

completely

assembled.

Proceed

to

the

ZPB

Board

Checkout

section.

North

Star

Z80A PROCESSOR

BOARD

14

BOARD

CHECKOUT

The

following

checkout

procedure

should

be

followed

for

a

newly

assembled

board.

It

can

also

be

used

to

diagnose

problems

in

previously

operational

boards.

This

checkout

procedure

assumes

that

no

other

board

besides

the

ZPB

is

plugged

into

the

S-100

bus.

This

makes

it

possible

to

get

the

ZPB

operational

even

if

no

other

board

in

the

system

is

yet

working.

This

procedure

assumes

only

that

the

correct

unregulated

voltages

have

·been

applied

to

the

bus,

that

the

computer

has

a

reset

switch,

and

that

the

bus

lines

are

not

shorted

to

each

other.

The

following

terms

are

used

in

specifying

expected

test

results.

GND

LOW

HIGH

+5V

AC

ground,

0

volts

DC

logic

zero,

0-.7

volts,

normally

about

.3

volts

logic

one,

2.4-5.0

volts,

normally

about

3

volts

+5

volts

from power

supply

Signal

with

pulses

(as

opposed

to

DC

signal)

When

referring

to

the

name

of

a

signal

from

the

schematic

drawings,

if

the

signal

is

identified

with

a

bar

over

its

name

then

the

name

of

the

signal

is

followed

by

a

slash

(e.g.,

STORE/)

in

the

checkout

instructions.

When

describing

an

AC

pulse,

the

notation

(±W,P)

refers

to

a

positive

or

negative

pulse

with

a

width

of

Wand

a

period

of

P.

For

example,

a

positive

pulse

of

width

125

nanosetonds

appearing

every

25

microseconds

would

be

represented

as

(+125ns,25us).

See

Appendix

1

for

details

on

how

to

detect

pulse

signals.

The

abbreviation

MB

before

a

number

indicates

a

bus

on

the

motherboard.

If

an

oscilloscope

will

be

used

to

test

the

board,

a

"scope

ground"

may

be

iristalled

by

soldering

a

"bridge"

of

jumper

~ire

between

the

two

PC

board

holes

that

connect

edge

connector

pins

50

and

100

near

location

2A.

Note

that

either

of

the

two

regulator

machine

screws

can

also

be

used

for

ground

test

points.

Cl.

Check

for

correct

clock

signals

on

the

ZPB

as

follows:

15

A.

Install

a

jumper

wire

at

PE

(near

location

4G)

if

the

PE

trace

was

has

been

cut.

B. Remove

the

lW

jumper

(near

location

6G)

if

it

was

previously

installed.

North

Star

Z80A

PROCESSOR

BOARD

C.

Install

a

jumper

wire

at

MW

(near

location

6A)

if

the

MW

trace

has

been

cut.

D.

with

the

computer

power

off,

install

only

the

ZPB

in

the

computer

motherboard.

E.

Turn

on

the

computer

power

and

check

for

the

following

signals.

Note

that

all

timing

signals

given

below

assume

the

ZPB

is

configured

for

standard

4MHz

operation.

Signal

Location

Description

PHI Z80

6 AC,

(+125ns,250ns)

PHI

2

MB

24

AC,

(+125ns,250ns)

PHI 1

MB

25 AC,

(+62ns,250ns)

2MHZ

CLOCK/

MB

49 AC,

(-250ns,500ns)

If

any

of

these

are

wrong,

trace

back

to

the

crystal

to

determine

the

cause.

C2.

This

step

will

check

the

reset

logic.

Use

the

same

setup

as

the

and

check

the

following

signals

while

alternately

depressing

and

releasing

the

computer

reset

switch.

Switch

Signal

Location

Depressed

Released

RESET/

MB

75

LOW

HIGH

7G

6

HIGH

LOW

RST/

5G

6

LOW

HIGH

POC/

MB

99

LOW

HIGH

C3.

Check

the

auto-jump

logic

as

follows:

A.

Leave

the

board

configured

as

in

the

B.

Turn

off

the

computer

power

and

remove

the

ZPB

from

the

computer.

Temporarily

connect

the

PRDY

signal

to

ground

by

soldering

a

piece

of

jumper

wire

beween

7F

5

and

7F

7

on

the

solder

side

of

the

ZPB. .

C.

Install

only

the

ZPB

in

the

computer

"motherboard

and

then

turn

on

the

power

and

depress

and

release

the

reset

switch.

The

processor

should

pause

immediately

after

performing

the

auto-jump

sequence

and

just

before

executing

the

first

instruction

at

the

auto-jump

address.

Check

that

the

SMI

signal

at

motherboard

44

is

HIGH.

D.

Assuming

the

jump

address

specified

on

the

header

at

location

E2

is

E800,

then

E800

should

be

on

the

motherboard

address

lines.

HIGH

signals

should

be

observed

on

the

following

motherboard

pins:

North

Star

Z80A PROCESSOR

BOARD

16

pins

32,

85, 86,

and

87.

LOW

signals

should

be

observed

on

the

following

motherboard

pins:

pins

29,

30, 31, 33, 34, 37,

79,

80,

81, 83,

and

84

The

processor

should

have

executed

a

single

instruction

(JMP

E800)

and

then

gone

into

a

wait

~tate

during

the

instruction

fetch

at

that

address.

The

Theory

of

Operation

section

describes

the

auto-jump

sequence.

If

SMI

is

high

but

the

address

is

wrong,

check

the

data

paths

through

the

POJ

header

and

multiplexors.

If

SMI

is

LOW,

skip

to

the

to

see

if

the

processor

can

execute

instructions

at

all.

If

SMI

has

an

AC

signal,

check

the

wait

logic

from

PRDY

to

WAIT/.

C4.

This

step

checks

out

the

Z80A

while

executing

a

one

instruction

program.

17

A.

With

the

power

off,

remove

the

jumper

from

PRDY

to

ground

from

the

ZPB.

B.

Turn

on

the

power

and

then

depress

and

release

the

reset

switch.

The

Z80

should

be

executing

an

RST

7

instruction

repeatedly.

Observe

that

all

the

data

input

(DI)

lines

are

HIGH

by

checking

the

following

motherboard

pins:

pins

41,

42,

43,

91, 93, 94,

and

95

C.

If

you

have

an

oscilloscope,

then

check

that

the

signals

ZD0-ZD7

are

HIGH

during

Ml

at

the

Z80A

chip

pins:

pins

14,

15,

12,

8,

7,

9,

10,

and

13

D.

Check

that

the

following

motherboard

address

lines

are

AC

signals:

pins

29-34,

37,

and

79-87.

E.

The

RST 7

instruction

causes

a

subroutine

call

to

location

0038

hex,

thus

the

stack

address

stored

will

be

0039

hex

(stored

as

alternating

00

byte

and

39

hex

byte).

Thus,

if

you

have

an

oscilloscope,

observing

the

data

output

bus

(DO),

the

following

motherboard

bus

pins

should

have

AC

signals

that

go

low

twice

every

2.75

microseconds:

pins

35,

40,

88,

and

90.

and

the

following

motherboard

bus

pins

should

have

AC

signals

that

go

low

once

every

2.75

microseconds:

pins

36,

38, 39,

and

89

North

Star

Z80A PROCESSOR

BOARD

F.

Check

for

the

following

signals

at

the

Z80

chip:

Signal

Location

Description

PHI

6

AC,

(+125ns,250ns)

Ml/

27

AC,

(-500ns,2750ns)

INT/

16

HIGH

NMI/

17

HIGH

WAIT/

24

HIGH

RST/

26

HIGH

Vcc pin- 11

+5V

ground

29

GND

G.

The

following

signals

should

be

observed

on

the

motherboard

bus

lines:

Signal

Location

Description

XRDY

3

HIGH

VI0/

4

HIGH

VII/

5

HIGH

VI2/

6

HIGH

VI3/

7

HIGH

VI4/

8

HIGH

VI5/

9

HIGH

VI6/

10

HIGH

VI7/

11

HIGH

NMI/

12

HIGH

STAT-DSBL/

18

HIGH

CC-DSBL/

19

HIGH

ADDR-DSBL/

22

HIGH

DO-DSBL/

23

HIGH

PHLDA

26

LOW

PWAIT

27

LOW

PINTE

28

HIGH

SMI

44

AC,

(+500ns,2750ns)

SOUT

45

LOW

SINP

46

LOW

SMEMR

47

AC,

(+375ns,2750ns)

SHLTA

48

LOW

SSW-DSBL/

53

HIGH

PMREQ/

65

AC,

4

~pulses

every

2750ns

PRFSH/

p;n

66

AC,

(-4

75ns,

2750ns)

MWRITE

pln

68

AC,

(+250ns

twice,2750ns)

RUN

71

HIGH

PINT/

p~n

73

HIGH

PHOLD/

pln

74

HIGH

PSYNC

76

AC,

3

+pulses

every

2750ns

PWR/

77

AC,

(-250ns

twice,

2750ns)

PDBIN

78

AC,

(+360ns,2750ns)

SWO/

97

AC,

(-250ns

twice,

2750ns)

North

Star

Z80A

PROCESSOR

BOARD

18

If

these

checkout

steps

have

been

successful,

then

the

ZPB

has

successfully

done

an

auto-jump

and

executed

a

simple

program.

Therefore,

most

of

the

circuits

on

the

ZPB

have

been

tested.

The

ZPB

should

now

have'

its

configuration

options

set.

Be

sure

to

remove

all

special

jumpers

added

during

the

checkout.

It

is

then

ready

to

be

used

in

conjunction

with

the

other

boards

in

the

computer

system.

If

the

PROM

option

is

being

used,

install

it

at

this

time.

Diagnosis

of

a

problem

in

a

previously

operational

board

will

usually

be

successful

using

the

following

procedure:

1.

Determine

that

the

ZPB

is

in

fact

the

board

that

has

the

problem

by

attempting

to

use

it

in

another

computer.

2.

Check

that

the

regulator

outputs

are

correct.

~hen,

in

an

orderly

fashion

begin

replacing

IC's

iti

the

ZPB

with

known

good

parts

until

the

probl~m

disappears.

If

a

board

that

was

working

has

not

been

subjected

to

any

abnormal

abuse

then

an

IC

failure

will

be

the

cause

of

the

problem

in

nearly

every

case.

3.

If

the

board

is

still

failing

then

the

problem

may

be

a

result

of

any

of

the

following

less

likely

conditions:

dirty

edge

connector

contacts,

bad

parts

other

than

the

IC's,

bad

connection

in

an

Ie

socket,

or

introduction

of

a

short

or

open

in

the

traces

on

the

board.

19

North

Star

Z80A

PROCESSOR

BOARD

North Star ZPB-A User manual

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