Zenith SM-Z-89 User manual

SM-Z-B9/90
Computer System
Service Manual
2.I'N data
~ systems
ZENITH DATA SYSTEMS
SAINT JOSEPH, MICHIGAN 49085
585-7
Copyright ©1982
Zenith Data Systems
All Rights Reserved
Printed in the United States of America

The Z-89/90 Computer System
This Z-89/90 ComputerSystem Service Manual contains service information for
the following six Zenith Data Systems products:
1. The Z-89/90 Computers.
2. The Z-89-37 Double-Density Disk Controller.
3.
The H-88-1 Single-Density Disk Controller.
4.
The H-17-1 Floppy Disk Drive.
5. The H-17-4 Floppy Disk Drive.
6.
The WH-88-16 Memory Expansion.
T

Z-89/90
Computers
Service Manual
ZENITH DATA SYSTEMS
SAINT JOSEPH, MICHIGAN 49085
I I
585-7
Copyright ©1982
Zenith Data Systems
All Rights Reserved
Printed in the United Statee of America

nl COMPUTER
Table of Contents
SPECIFICATIONS 1-1
CPU Boards Z-89/90 , , 1-2
SETUP AND TESTING
2-1
Power Line Considerations ,......... 2-1
Cabinet Removal ,2-2
ZDS SYSTEM CONFIGURATION , .
.. 3-1
Terminal Logic Circuit Board 3-1
CPU Logic Circuit Board 3-4
Serial Interface 3-20
Memory
Map 3-22
I/O Port Usage 3-22
OPERATION "4-1
Command Summary 4-1
Keyboard
Operation. . . . . . . . . . . . . . . . . . . . . .. 4-3
Normal Modes
and Keys ., 4-5
CIRCUIT DESCRIPTION 5-1
Power Supply Circuit B~~~d' ::::::::::::: :: 5-2
Video Deflection Circuit Board 5-3
Video Driver Circuit Board
::::::::::::: 5-6
Terminal Logic Circuit Board 5-6
CPU Logic Circuit Board 5-15
Serial Interface I/O Circuit Board 5-21
Block Diagrams fold-outs
SERVICE ,6-1
CRT Adjustment 6-2
Switch Configurations 6-4
CPU Logic Circuit Board 6-6
Rotational
Speed Test 6-22
Memory Testing
.. , , 6-23
Troubleshooting Charts 6-25
CIRCUIT BOARD X-RAY VIEWS
7-1
SEMICONDUCTOR IDENTIFICATION CHARTS 8-1
Component
Number Index ,8-1
Part
Number Index 8-4
REPLACEMENT PARTS LIST 9-1
Power
Supply 9-1
Video Deflection Circuit Board 9-1
Video Driver Circuit Board 9-3
Terminal Logic Circuit Board 9-3
CPU Logic Circuit Board 9-4
Chassis Parts 9-5
Serial Interface I/O Circuit
Board. . . . . . . . . .. 9-6
SCHEMATIC DIAGRAMS fold-in

COMPUTER 11-1
Specificalions
CPU AND MEMORY
Processor .
Clock .
Memory .
DISPLAY
CRT .
Display Format .
Display Size .
Character Size .
Character
Type .
Keyboard .
Cursor .
Cursor Controls .
Cursor
Addressing .
Tab .
Refresh Rate .
Edit
Functions .
Erase
Functions .
Bell .
Video .
Z-80.
2.048 MHz.
48K bytes
user RAM (expandable to 64K), Z-89 series
64K bytes
user RAM, Z-90 series 8K System for ROM
and RAM. 8K reserved.
12" diagonal -green
phosphor.
24 lines of 80 characters (with access to 25th line).
6.5"
high x8.5" wide.
0.2"
high x0.1" wide (approximate).
5 x 7
dot matrix (upper case); 5 x 9 dot matrix (lower
case
with descenders); 8 x 10 dot matrix (graphics).
84 keys (60
alphanumeric, 12 function/control) plus a
12-key
numeric/control pad.
Blinking,
nondestructive, underline, block, or dis-
abled (DIP switch selectable).
Up,
down, left, right, home, CR, LF, back space, tab,
and cursor off.
Relative
and direct.
Standard 8-column tab.
60 Hz at 60 HZ/50 Hz at
50 Hz line frequency.
Insert and delete character or line.
Erase page, erase to
end of line, and erase to end of
page.
Audible alarm on receipt of ASCII BEL.
Normal and reverse by character.

1-
21
COMPUTER
SERIAL INTERFACE
Channels. '" " .
Output Levels .
Input Levels .
Character Length .
Parity .
Stop Bits .
Baud Rates .
GENERAL
Power Requirements .
Size .
Weight .
Operating
Temperature .
Storage
Temperature .
3
EIA RS-232C.
Each
channel provides serial data and primary RS-
232C
handshake.
RS-232C.
RS-232C compatible.
5,6,7, or 8bits.
Even, odd, stick, or none.
1, 1-1/2 or 2.
All standard rates to 57,600 baud.
115/230 volts at 90
watts max.
13"
high x 17" wide x 20" deep
(3:3 x43.2 x50.8 em).
46 lbs. (20.7 kg).
10° to 35° Celsius.
0° to 50° Celsius.
CPU BOARDS Z·89/90
The CPU boards for the Z-89 (HE 181-3396) and the Z-90 (HE 181-3615) are basically the same, with the
following exceptions:
Z-89
Z-90
IC U516
HE 444-41
HE 444-83
IC U518
HE 444-62
HE 444-84
IC U549
HE 443-904
See
note 1.
IC U557
HE 443-912
See
note 2.
IC U558
HE 443-754
HE 100-1817
NOTE
1: The memory chip is left out to receive the cable from the 16K Memory Expansion Board.
NOTE
2: U557 is left open to receive the interface cable from the Z-89-37 Controller Board.
The Z-90 CPU boardhas the JJ505 jumper plug removed. Cable (HE 134-1159) is connected from JJ505 to Pin
14 of P508, to enable the 4K ROM at U518.
JJ501 must be jumpered for correct memory size (48K or 64K).
Theseboardsmay be
interchanged if the above modificationsare made. The Z-90 CPU board may be used as
a
direct replacement if the proper IC's are inserted at U549, U557, and U558. U516 and U518 do not have to
be
changed.
Zenith Data Systemsreserves the right to discontinue
products and to change specifications at any time
without incurring any obligation to incorporate new
features in products previously sold.

COMPUTER, 12-1
Setup and l'esting
POWER LINE CONSIDERATIONS
If you need to change the position of the 115/230
switch (located
on the bottom of the Computer), be
sure you change rear panel fuse F1 to the proper value
as follows:
For 115 VAC, use a1.5-ampere, 125-volt, slow-
blow fuse.
For 230 VAC, use a
I-ampere, 250-volt, slow-
blow fuse.
The plug on the power cord is for standard 115 V AC
outlets. For 230 VAC operation in the U.S.A., cut off
and replace in a manner such that your power connec-
tion conforms
with section 210-21 (b) ofthe National
Electric Code,
which reads, in part:
"Receptacles
connected to circuits having dif-
ferent voltages, frequencies, or types of
current
(AC or DC) on the samepremises shall beof such
design that attachment plugs used on such cir-
cuits are
not interchangeable."
When you install the new plug, make sure it is con-
nected according to your local electrical code. Units
with three-wire line cords must
always have the
green wire connected to chassis ground.
Be sure the NORM/LOW switch (on the bottom of the
Computer) is set in its proper position to match your
line voltage as follows:
NORM range -110 Vto 130 V
rms or 220 Vto
260 Vrms.
LOWrange-100 Vto 120 Vrms or 200 Vto 240
Vrms.
NOTE:
If you do not know the value ofthe line voltage
in your area, set the NORM/LOW switch to NORM.

2-2IL- ------COMPUTER
CABINET REMOVAL
Whenever you need to remove the cabinet top:
•Refer to
the inset drawing on Figure 2-1,
insert the blade of a small screwdriver into
the notch in the latch plate, and then, as you
lift upward on the front, slide the latch plate
toward the front ofthe Computer about 1/4".
•Likewise, open the latch plate on the other
side of
the cabinet top.
• WARNING: When the line cord is con-
nected to an AC outlet, hazardous voltages
can be present inside your Computer. See
Figure 2-1.
•Carefully tilt the cabinet top back.
•
Unplug the fan.
•
When the top is tilted straight up, carefully
lift
the hinges out of the rear panel.
Simply reverse this procedure to close and lock the
cabinet top back on the Computer.
WARNING: Boxed-In areas show
~ hazardous voltage locations.
~
~
~
TI LT
BACK
Figure 2-1

COMPUTER_-----------------------13-1
ZDS System Configuration
This section of the Manual shows you the normal
switch and jumper positions. Check them to be sure
they are in their proper positions, or set them (as
explained) for
the operation that is desired.
The Computer communicates with the peripherals at
RS-232C signal levels. 25-pin
"D" connectors on the
rear panel conform to RS-232C standards and mate
with most equipment that conforms to this standard.
Refer to the following sections that pertain to your
Computer.
TERMINAL LOGIC CIRCUIT BOARD
Carefully tilt back the cabinet top. See Figure 2-1.
Be
sure the POWER switch is off. Then remove the
screws that hold the terminal logic circuit board (the
rear circuit board). Remove
the two screws that hold
the top of the CPU logic circuit board. Disconnect the
cables, as necessary, and lift the circuit boards up out
of the Computer.
SWITCH S402 (Secondary power-up configura-
tion)
Push all of the switches on S402 up (0) as shown in
Figure 3-1 on Page 3-2.
If you ever want to change these switch positions,
they are
defined as follows:
SWITCH
SECTION DESCRIPTION
0o=
underscore cursor; 1=block cursor
1o=key click; 1=
no key click
2o=
discard past end of line; 1= wrap
around
3o=
no auto LF on CR; 1= auto LF on CR
4o=
no auto CR on LF; 1= auto CR on LF
5o=ZDS mode; 1=ANSI mode
6o=
keypad normal; 1= keypad shifted
7o=60 Hz refresh; 1=50 Hz refresh

3-
2
11.- , COMPUT;£R
SWITCH S401 (Primary power-up configura-
tion)
Refer to Figure 3-1 for the following steps.
This switch (located on the terminal logic circuit
board) sets
the following power-up and reset modes:
SWITCH
SECTION DESCRIPTION
0-3 Baud Rate
4Parity Enable
5 Odd/Even Parity
6Normal/Stick Parity
7Half/Full
Duplex
The particular configuration that you select is ini-
tialized
when you power-up the Computer or when
you perform a Computer Reset. Figure 3-1 shows the
location of switch S401. Remember that, as you look
at
switch S401 from the front of the Computer, you
select the one (1) positions of the switch by pushing
the switches down, and you select the zero (0) posi-
tions by pushing the switches up.
Set switch S401 for:
MODE SWITCH SECTION
0 1 234567
--
9600 Baud 001 1
No Parity 0
Odd Parity 0
Normal Parity 0
Full
Duplex
1
L--_
When no parity is selected, you can set the even and
normal parity switch sections to either position since
they will be ignored.
Each
function of switch S401 is explained in the fol-
lowing text.
"",
r®l
==[JI==@==T
m,
~ ,-
Figure 3·1
o5402
~n~~e~~~~~
1 10 12 34_.? .6_ 7
(ON).
.'; : <---------.',
........ J ";" ..; ;', ; , .. :,'"
•
!
~_ •. - •.• _. - _ ... ._. __ . . .-l
•....•.. ,_.
•...
.. __ •..•. _-_.
5401
o ' .. < .• :_
1 aa~~~8B~ ~!u:/_:
1 0' 234567
.----- --- - -.- (ON)- -------
! .: •

COMPUTERL- 13-3
Baud Rate
When used asa Computer, the baud rate must be set to
9600. If you use your Computer as a terminal, you can
reset
the baud rate as explained below.
Odd/Even Parity
If section 4=1, then section 5of switch S401 selects
odd or even parity.
Normal/Stick Parity
ZDS Software supports full duplex operation. Setsec-
tion 7 to 1for full duplex operation.
Section 7of switch S401 selects either full or half
duplex communications between the Computer and
the terminal sections.
If section 4=1, then section 6of switch S401 sets the
ACE to transmit and receive either stick or normal
parity.
You
can select any of 12 different baud rates (110-
9600).
To do this, place sections 0, 1, 2, and 3of
switch S401 to the proper positions as shown below.
The baud rate will be initialized (or updated) upon
Reset or during power-up.
BAUD SWITCH SECTION
RATE 0 1 2 3
N/A
0 0 00
110 1 0 0 0
150 0 1 0 0
300 1 1 0 0
600 00 1 0
1200 10 1 0
1800 0 1 1 0
2000 1110
2400 000 1
3600 100 1
4800 0 1 0 1
7200 1101
9600 00 1 1
19200* 10 1 1
Down (1)
Up (0)
Down (1)
Up (0)
Half/Full Duplex
Down (1)
Up (0)
Even Parity
Odd Parity
Stick Parity
Normal
Full Duplex
Half Duplex
Parity
You can program the ACE (Asynchronous Communi"
cation Element) to either generate or eliminate the
parity bit. Section 4of switch S401 selects the parity
bit.
Replace
the circuit boards and reconnect their cables.
Down (1)
Up (0)
Parity
No Parity
ZDS Software
does not check parity.
*Not currently supported (may drop characters)

3-
4
IL COMPUTER
CPU LOGIC CIRCUIT BOARD
Switch SW501
The functions that switch SWSOl selects are deter-
mined by integrated circuit U518. See Figure 3-2.
5-1/4/1 HARD-SECTORED FLOPPY USAGE
When you use a 5-1/4/1 hard-sectored floppy disk,
integrated
circuits part numbers HE 444-40, HE 444-
62,
or HE 444-84 must be installed at U518. Set
SW501
switch sections as directed in the next two
steps. Then proceed directly to "Programming Jum-
pers." See Figure 3-2.
Set SW501 section 5 to "i."
Set the remaining seven SWSOl sections to "0."
L...---t
U-uuu
uuu
Figure 3-2
CPU board.
I I

COMPUTER 13-5
8" FLOPPY DISK (Z-47) USAGE
When you use an 8" floppy disk (Z-47), integrated
circuit part numbers HE 444-62 or HE 444-84 must be
installed at U518.
• When you boot up from a5-1/4" hard-
sectored floppy disk to enable your 8"
floppy disk, set SW501 switch sections as
directed in the next two steps. Then proceed
directly to "Programming Jumpers." See
Figure 3-2.
Set SW501
switch sections 2 and 5to "1."
Set the remaining six SW501 sections to "0."
• When you boot up from the left-hand 8"
floppy disk drive, set SW501 switch sec-
tions as
directed in the next two steps. Then
proceed directly to "Programming
Jumpers."
Set SW501
switch sections 2, 4, and 5to "1."
Set the remaining five SW501 switch sections to "0."
8" FLOPPY DISK (Z-67) USAGE
There are four ways of installing the Interface Board.
How you install yours depends on what equipment
you already have. If you have:
1. AZ-89-37 Double-Density Controller, you must
install your Interface Board as shown in Figure
3-3 on Page 3-6. Switch SW501 on the CPU Board
must be set as shown in inset drawing #1. The
jumpers on the Interface Board must be set as
shown in inset drawing #2.
2. An H-88-1 Disk Controller, you must install your
Z-89-67 InterfaceBoard as shown in Figure 3-4 on
Page 3-7. Set switch SW501 as shown in inset
drawing #1, and the jumpers as shown in inset
drawing #2.
3. AZ-89-47 Interface Board, you must install your
Z-89-67 InterfaceBoard as shown in Figure 3-5 on
Page 3-8. Set switch SW501 as shown in inset
drawing #1, and the jumpers as shown in inset
drawing #2.
4. None of the Above, install your InterfaceBoard as
shown in Figure 3-6 on Page 3-9. Set switch
SW501 as shown in inset drawing #1, and the
jumpers as shown in inset drawing #2.
You may set the DIP switches on the Interface Board
in any position when you are using Zenith software.

3-
6
IL COMPUTER
CPU LOGIC
CI
RCU IT BOARD
___ --I NS ET #2 --- ..... z::-.... ....
~ ~
•
JUMPERS ON Z-89-67 BOARD
•
•
•
• DO NOT MOVE
D7E~;
IiDd1IUDD'
'----\.i--
JUMPER THESE WHEN US ING
P506 AND P512
n ~~ ~ ~~
on
O
S l)
~to~
0-89-37 SERIAL '-89-67
HERE BOAR D HERE
HERE
Figure 3-3

COMPUTERI- 13-7
CPU LOGIC
CIRCU IT BOARD
~ ....... ---INSET #2--- __
~
JUMPERS ON Z-89-67 BOARD
SWITCH SW501
•
•
•
•
• DO NOT MOVE
D~ THESE JUMPERS
:/~D
liD dDooo'
-----\.7·- .....
JUMPER THESE WHEN US ING
P504 AND P510
H-88-1 J-
HERE -,
i
c:- t-
SERIAL
BOA RD
HERE
I
i~
(J-!
Z -89-67
HERE
r-
~
rC
i-1
rL,
I'
Iu
Ll
lSI
I
LJ
Figure 3-4

CPU LOGIC
CIRCUIT BOARD
~ .... ---INSET #2-- ...........
~ ~
JUMPERS ON Z-89-67 BOARD
•
•
•
•
• DO NOT MOVE
D7[~:
liD ClDooo .
'----~.i,- ....
JUMPER THESE WHEN US ING
P506 AND P512
I I
n
T
§L~
I
Z-89-67
HERE
SERIAL
BOARD
HERE
lJ ~
n rB
l-
ULJ
HERE
I~
(d-
I
I
U
[cue
i-L"
i~
II
Figure 3·5
II

COMPUTERI------- , 3·9
CPU LOGIC
CIRCUIT BOARD
~ .... -----INSET #2 -- __
~ .........
JUMPERS ON Z-89-67 BOARD
SWITCH SW501
•
•
•
••
DO NOT MOVE
D~ THE SE JUM PER S
:J~D'
• • •
IiDcmUOO'
'----\.i- ....
JUMPER THESE WHEN US ING
P506 AND P512
Z-89-67=:1-
HERE) -l
I
I
----@~
HERE
-I--l-
II
I
:~
-c-
iV-I
I0
'"
ICL
~J
~J:-
I
I
~~I
,'
I I
LI
Figure 3·6
II

3-101~ roMM~
Z-89-37 INTERFACE BOARD USAGE
Z-89·47
For asystem to operate properly with the Z-89-37, the
Z-89-47 I/O board should be installed at plugs P506
and P512. However, before the Z-89-47 will operate
properly when plugged into plugs P506 and P512. a
resistor
must be added to the Z-89-47 circuit board.
To make
the modification use a4700 n. 1/4-watt
resistor. HE-6-472 (yellow-violet-red),
slide a length
of sleeving over the resistor and solder the resistor
between pins 1 and 12 of plug P2 on the foil side (not
the component side) of the Z-89-47 circuit board.
Refer to
Figure 3-7.
Set
the 170/174 programming plug to 174.
Install
the Z-89-47 board at plugs P506 and P512.
NOTE:
If you ever move this board to another set of
plugs, be
sure to remove the 4700 nresistor that you
just installed.
H- 88-l
FLOPPY DISK
110
CIRCUIT
BOARD
• • •
·. '.'
· . ..
Figure 3-7

COMPUTERI- ---J13-11
PROGRAMMING MODULES
Refer to Figure 3-8 on Page 3-12 as you read the
following information.
Use the following information for any special
configurations that you may want.
Programming modules:
We
recommend that you do not use
both 48 and 96 TPI drives in the same
system,
since the precompensation
will be wrong for at least one of the
drives. This can result in reduced
data reliability. When precompensa-
tion is selected, it is factory pre-set to
300 nanoseconds.
J1 & J2
13
Select port 170 or 174. (Both jumpers
must be at 170, or both jumpers must
be at 174. 170 is normal.)
1=No precompensation; 0=pre-
compensation.
(1 position is normal.)
Use
"0" if any of your drives are 48
TPI Wangco Model 82 (HE 150-71)
drives. Otherwise,
use "1."
J4 - J7
Selects which drive is connected to
plug P3. (Drive numbers are deter-
mined by how the drive program-
ming modules are cut. See Figure
3-8.)
J4 =DS1
J5 =DS2
J6 =DS3
J7 =DS4 (presently not supported)

COMPUTER
3-
12
1 -----
Figure 3-8
Z-89-37 Interface Board
iI I I