Tandy WP-2 User manual

TANDY9
Service
®
Tandy WP-2
Portable Wordprocessor
Catalog Number: 26-3930
SPECIFICATIONS
Microprocessor
Clock Speed
Memory
Keyboard
Display
Externa] Connections
Battery
AC Adapter
Power Consumption
(ai 6VDC)
NEC 70008A-6(Z80 type)
5.5296 MHz
256 KByte Standard ROM (BIOS, WORDPROCESSOR, and speli check), 32 KByte Standard RAM
(VRAM and Free Area)
ROM: Option (IC Card) Expandable up to 256 Kbyte
RAM: Option (RAM chip) Expandable 32 Kbyte or 128 Kbyte (RAM Disk)
Option (IC Card) Expandable 32 Kbyte, 64 Kbyte, 128 Kbyte (IC Card)
Full-size 62 keys.
"Supertwist" LCD, 480 X64 pixels, 8 X80 characters
AC Adapter
DB-25 Parallel Printer
DB-9 Serial Port
DIN-8 Cassette Tape
IC Card-38 Memory Card
AA size battery X4, Alkaline or Ni-Cd
6VDC 400 mA, UL listed (Cat. No. 26-3804)
UNIT NORMAL LIMIT
mA 80-90 140
©1989 Tandy Corporation.
All Rights Reserved.
Radio Shack and Tandy are registered trademarks of Tandy Corporation.

CONTENTS
Section ISYSTEM OVERVIEW .. 1-1
1-1 External View 1-1
I-2 Internal View.. 1-4
I-3 Specifications 1-6
Section II DISASSEMBLY INSTRUCTIONS 2-1
11-1 Top Case 2-1
II-2 Keyboard 2-3
II-3 LCD 2-4
II-4 Main PCB 2-4
II-5 Sub PCB 2-6
Section III MAINTENANCE 3-1
lll-l Clean the Case and LCD Display 3-1
Section IV Theory of Operation 4-1
IV-1 Hardware Specifications 4-1
IV-2 Description of Block Diagram 4-4
IV-3 CPU 4-4
IV-4 Memory Map 4-5
IV-5 Main RAM Control Circuit 4-5
IV-6 Expansion RAM Control Circuit 4-6
IV-7 ROM Control Circuit 4-6
IV-8 I/O Address Map 4-7
IV-9 Interrupt 4-9
IV-10 Keyboard 4-9
IV-1 1Cassette Interface Circuit 4-10
IV-1 2Printer Interface Circuit 4-11
IV-1 3Serial Interface Circuit 4-12
IV-1 4Buzzer Control Circuit 4-13
IV-1 5LCD Controller 4-13
IV-1 6Power Supply 4-14
IV-1 7Software Calls 4-1
6
IV-1 8Software and Hardware Memory Map 4-17
IV-19 IC Card 4-20

Section VTROUBLESHOOTING 5-1
Section VI EXPLODED VIEW/PARTS LIST 6-1
VI-1 Exploded View 6-1
VI-2 Electrical Parts List 6-2
Main PCB Assembly 6-2
LCD Unit 6-6
Mechanical and Assembly Parts 6-7
Keyboard Unit 6-8
Section VII PCB VIEWS 7-1
VII-1 Main PCB Top View 7-1
VM-2 Main PCB Bottom View 7-2
VII-3 LCD PCB View 7-3
Section VIM CIRCUIT DIAGRAMS 8-1
VIII-1 Main PCB Circuit Diagrams -8-1
APPENDICES
Appendix A. LCD SPECIFICATIONS A-1
1. Application A-1
2. Composition A-1
3. Mechanical Specifications A-2
4. Electrical Specifications -A-3
5. Interface Specifications A-5
6. Optical Characteristics..... A-9
7. Precautions in Use A-1
1
8. LCD Module View A-1
3
Appendix B. INSTALLATION OF OPTIONAL RAM B-1
Appendix C. KEYBOARD LAYOUT, CONNECTER PIN ASSIGNMENTS,
AND CHARACTER CODE TABLES. C-1
1
.
Keyboard Layout C-1
2. Connector Pin Assignments C-2
3. Character Code Tables C-5
Appendix D. ROM CALLS AND SPELLER INFORMATION D-1
1. ROM Calls D-1
2. Speller Information D-1
3

List of Illustrations
Table Page
Number DESCRIPTION Number
1-1 Front View 1-1
1-2 Rear View 1-2
1-3 Bottom View 1-3
1-4 Main PCB 1-4
1-5 LCD PCB 1-5
2-1 DSUB Connector Screw Removal 2-1
2-2 Removal of Main Batteries 2-1
2-3 Top Case Removal ,2-2
2-4 LCD Cable Removal 2-2
2-5 Keyboard Removal 2-3
2-6 LCD Removal 2-4
2-7 Main PCB Removal 2-5
2-8 Back-up Battery Cover and Back-up Battery Removal 2-6
2-9 Lower Case View 2-6
4-1 Block Diagram ,4-3
4-2 Memory Map 4.5
4-3 Main RAM Control Circuit 4-5
4-4 Expansion RAM Control Circuit 4-6
4-5 ROM Control Circuit 4-6
4-6 Interrupt Control 4-9
4-7 Keyboard Control ,4-9
4-8 Cassette Interface Circuit 4-10
4-9 Printer Interface Circuit ,4.11
4-10 Serial Interface 4-12
4-1
1
Buzzer Control Circuit 4-1
3
4-12 LCD Controller ,4-13
4-13 Power Supply 4-14
4-14 Power Supply Circuit 4-15
6-1 Exploded Vrew 6-1
7-1 Main PCB Top View 7-1
7-2 Main PCB Bottom View 7-2
7-3 LCD PCB View 7-3
A-1 Block Diagram A-1
A-2 Dot Dimensional Drawing A-2
A-3 Vo Adjusting Circuit ,A-4
A-4 LCD Screen A-5
A-5 Timing Chart A-6
A-6 Timing Chart a-8
A-7 Timing Chart A-8
A-8 Optical Characteristics Measurement System A-9
A-9 Definition of Response Time A-9
A-10 Definition of 8and <b A-10
A-11 Definition of Contrast Ratio A-10
A-1
2
Operational Precautions A-1
2
A-1
3
LCD Module A-13
B-1 RAM Insertion B-1
C-1 Keyboard ,C-1
C-2 Keyboard ,C-1
C-3 RS-232C Connector ,C-4
C-4 Cassette Connector ,,C-4
C-5 Printer Connector C-4
C-6 External Card Connector ,C-4
ni

List of Tables
Table Page
Number DESCRIPTION Number
C-1 RS-232C Interface C-2
C-2 Cassette Interface C-2
C-3 Printer Interface C-2
C-4 Expansion Card Interface ,C-3
C-5 Character Code Table C-5
C-6 ESC Sequence Code (VT52) C-11
]V

I. SYSTEM OVERVIEW
This manual has been prepared for Tandy technicians working in the field or in repair centers. Users of this manual
should be acquainted with the ^PD70008A-6 microprocessor and the 82C51 UART.
The Tandy WP-2 has the following applications programs in the standard ROM: TEXT, TELCOM, PHONE(AD-
DRESS), CALENDAR(SCHEDULE), SPELLCHECK, and FILES.
1-1. External View
1. Keyboard: Can be used like astandard typewriter. However, the Tandy WP-2 does have afew special keys, (See
Appendix Cof this manual for more details.)
2. LCD Screen: The Tandy WP-2 display is eight lines by 80 characters.
3. Power Switch: Pressing this switch turns the power on and off. To conserve the batteries, the Tandy WP-2
automatically turns the power off if you do not use it for 10 minutes in the default setting.
4. CONTRAST control: This control adjusts the contrast of the LCD display.
5. PROTECT Switch: This switch is used to prevent discharge of the Lithium battery, used for RAM back up. The
Tandy WP-2 operates only when the power switch is set to ON. Set this switch to the OFF position when the Tandy
WP-2 will not be used for along period of time. Note that the RAM is not backed up when this switch is set to
the OFF position, and all information RAM in will be lost.
LCD Screen
1.Keyboard
3. Power Switch
5. Protection Switch
4. Contrast Control
Figure 1-1. Front View
i-i

1. Expansion Card (IC Memory) Slol: Insert the IC memory card into this slot. The connector in the slot is connected
to the system bus of the CPU.
2. Serial Interface Connector (RS232C): Attach aDB-9 cable (such as Radio Shack Catalog Number 26-265) to this
connector when you need to receive or transmit serial information. This connector is also used for the FDD.
3. Printer Interface Connector: For hard-copy printouts of information, attach any Radio Shack parallel printer to this
connector, using an optional/extra printer cable.
4. Cassette Interface Connector: To save or load information on acassette tape, connect the cassette recorder here.
An optional/extra cassette recorder cable is required.
5. AC Adapter Jack: Connect the appropriate end of Radio Shack's AC adapter {Catalog Number 26-3804, optional/
extra) to this connector. Connect the other end of the AC adapter to astandard AC wall-outlet or approved power
strip.
3. Printer Interface Connector
4. Cassette Interface Connector
©Seriaf Interface Connector (RS232C)
©Expansion Card Slot
5. AC Adapter Jack
Figure 1-2. Rear View
1-2

1. Main Battery Compartment: When an AC adapter is not connected, the Tandy WP-2 gets its power from four AA
size batteries installed in this compartment.
2. Back-up Battery Compartment: The Tandy WP-2 gets RAM back-up power from aLithium battery (CR-2430)
installed in this compartment.
3. RESET Button Hole: If the Tandy WP-2 locks up (i.e., the display "freezes" and all keys seem to be inoperative),
push this button; the display returns to the Main menu (siari-up). All data stored in RAM will be lost when you
press RESET. It is not likely that the Tandy WP-2 will lock up when you are using the built-in applications programs.
However, it might occur with customized programs.
4. Stands: Pull down to make the WP-2 sit at an angle.
©Main Battery Compartment ©Back-up Battery Compartment
IB
«O
^R^!-,l:^KM :] N-:UI. :.la.|
ifeVaH&KT.jq
"=
SJAL
33!
iB
ET
(=^~
3>
o©
\
O©
(S) Reset Button
©Stands
Figure 1-3. Bottom View
1-3

1-2. Internal View
Optional RAM Compartment: An optional RAM can be inserted into this compartment to enhance the Tandy WP-2
capabilities.
The Tandy WP-2 consists of four printed circuit boards:
*LCD PCB
*Keyboard PCB
*Main PCB
*Sub PCB
Figure 1-4. Main PCB (Bottom View and Top View)
[-4

Figure 1-5. LCD PCB
1-5

1-3. Specifications
Main Components
Keyboard
Life of keyboard
Number of keys
All keys
Power switch
LCD display
Display panel
Dol pitch
Dot size
Effective display area
Operation batteries
Batteries
Operation time
(approximately)
Memory protection battery
Battery
Back-up time
LSls
CPU
500 million keystrokes
62 keys {8X8 key matrix)
Keys can be pressed down adistance of 3millimeters.
Press the switch down 1millimeter to turn the WP-2 on or off.
480 X64 full-dot matrix
0.44 X0.44 mm
0.41 X0.41 mm
211.16 (W) X28.12 (D) mm
Type AA X4
Alkaline-manganese batteries
3.5 days (typ.)-4 hours per day
14 days (typ.)-l hour per day
(Note: Without I/O units at normal temperature)
Lithium battery (270 mAh/3.6V)
More than 3years
32 KByte RAM
1.5 years (typical)
32 KByte +32 KByte RAM option
1.5 years (typical)
32 KByte +128 KByte RAM option
MPD70008A-6
Code compatible with Z80
ROM Maximum 256 KByte
(Memory card)
Standard 256 KByte
256 KByte
RAM
Power consumption
Dimensions
Weight
Maximum 32 KByte +256 KByte
(Memory card +Optional)
Standard 32 KByte
Optional 128 KByte
80 mA (typ. at 6VDC)
1" (H) X11-2/3" (W) X8-2/7" (D)
25.4 (H) X297 (W) X210 (D) mm
2.42 Ibs.(l.lkg) with batteries
1-6

I/O Interface
RS-232C
Conforms to EIA standard signal
Communications protocol
Word length
Parity
Stop bit length
Baud rate
XON/XOFF
CR/LF
XMODEM
TXD (Transmit Data)
RXD (Receive Data)
RTS (Request to Send)
CTS (Clear to Send)
DSR (Data Set Ready)
DTR (Data Terminal Ready)
CD (Carrier Detect)
5, 6, 7, or 8bit
NONE, EVEN or ODD
1, 1.5, or 2bit
75, 110, 150, 300, 600, 1200, 2400, 4800, or 9600 bps
(19200 bps: when used for the FDD)
Enable/Disable
CR/LF/CR +LF
ASCI1/CRC-XMODEM
Maximum transmission distance 16,5 feet (5 meters)
Maximum driver output voltage +5 volts and —8 volts
Maximum receiver input voltage ±15 volts
Minimum receiver input voltage ±3volts
Printer interface
Conforms to Centronics interface standards
Handshake signals /STROBE, BUSY. /BUSY
Audio cassette interface
Data transfer rate 1500 BPS
(Mark 2400 Hz, Space 1200 Hz)
Input level 0.8 to 5volts (peak-to-peak)
Output level 600 mV (peak-to-peak)
Expansion card interface
RAM card
ROM card
32 KHyte, 64 KByte, or 128 KByte
Less than or equal to 256 KByte
1-7

II. DISASSEMBLY INSTRUCTIONS
II- 1. Top Case
1. Remove 4hexagon screws from the CN3/CN6 DSUB Connector.
Figure 2-1. DSUB Connector Screw Removal
2. Remove the Main Batteries.
Figure 2-2. Removal of Main Batteries
2-1

3. Remove 5screws "A" from the lower ease.
4. Remove ihe upper case.
The upper and lower cases are secured by snaps. Pull up the front of the upper case first, as shown below.
Do not apply loo much force when pulling it.
Figure 2-3. Top Case Removal
5. Disconnect the LCD flat cable from the connector on the main PCB.
Figure 2-4. LCD Cable Removal
2-2

11-2. Keyboard
1. Remove 2screws "B" securing the keyboard to the bottom case.
2. Disconnect the keyboard flat cable from the connector on the main PCB.
3. Remove the keyboard. B
Figure 2-5. Keyboard Removal
2-3

II-3. LCD
1. Remove 4screws 'C securing the LCD PCB to the upper case.
2. Remove the LCD PCB.
Figure 2-6. LCD Removal
II-4. Main PCB
1. Disconnect the flat battery cable from the connector on the main PCB.
2. Remove the five electric wires for the cassette connector using asoldering iron.
Wire assignment
'Brown
2Red
3Orange
4Yellow
5Green
3. Remove 1screw "D" securing the main PCB to the bottom case.
2-4

4. Remove the main PCB.
Main PCB
Insulator Sheet
5. Remove the insulator sheet.
6. Remove the shield board.
Figure 2-7. Main PCB Removal
2-5

II-5. Sub PCB
l. Remove the back-up battery cover and the Lithium battery.
Figure 2-8. Back-up Battery Cover and Back-up Battery Removal
2. Remove the spring for the negative battery terminal.
3. Remove the main positive battery terminal.
4. Remove the buzzer.
5. Remove the sub PCB.
Figure 2-9. Lower Case View
2-6