Toshiba T4700CS User manual

T4700CS, T4700CT, T4800CT 1-1
1.1 Features
The Toshiba T4700CS/T4700CT/T4800CT is one of the lightest and most advanced portable
computers available. Utilizing advanced technology and high-speed components, the
T4700CS/T4700CT/T4800CT offers excellent color display legibility, battery operation and
IBM PC/AT compatibility. The T4700CS/T4700CT/T4800CT system unit consists of the
following features:
❑Microprocessor
The T4700CS/T4700CT uses an SL Enhanced Intel 486TMDX2 Microprocessor
(referred to as 486DX2 in this manual) that operates at 50 MHz, 3.3 Volts.
The T4800CT uses an SL Enhanced Intel 486TMDX4 Microprocessor (referred to as
486DX4 in this manual) that operates at 75 MHz, 3.3 Volts.
❑Math co-processor
The T4700CS/T4700CT has a math co-processor which is stored in the 486DX2.
The T4800CT has a math co-processor which is stored in the 486DX4.
❑Cache memory
The T4700CS/T4700CT has an 8 KB cache memory which is stored in the 486DX2.
The T4800CT has an 16-KB cache memory which is stored in the 486DX4.
❑Disk storage
The T4700CS/T4700CT has an internal 200- or 320-Megabyte (MB) Hard Disk Drive
(HDD) with an average access time of 12 milliseconds. A 3.5-inch Floppy Disk Drive
(FDD) supports 2HD floppy disks (1.44 Mbytes) and 2DD floppy disks (720 Kbytes).
The T4800CT has an internal 320 or 500 MB HDD with an average access time of 12
milliseconds. A 3.5-inch FDD supports 2HD floppy disks (1.44 Mbytes) and 2DD
floppy disks (720 Kbytes).
❑Memory
The T4700CS/T4700CT/T4800CT comes standard with 8 MB of CMOS Random
Access Memory (RAM) 3.3 Volts. This includes 640 KB of conventional memory and
7,424 KB of extended memory which can be utilized as expanded memory compatible
with the Lotus/Intel/Microsoft Expanded Memory Specifications (LIM-EMS).

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❑STN color LCD (T4700CS)
A high-resolution 9.5-inch full-color, Supertwist Nematic (STN) color Liquid Crystal
Display (LCD) displays 640x480 pixels with 226,981 colors for both graphics and
characters. The T4700CS internal display controller supports Video Graphics Array
(VGA) functions on the internal display devices.
The T4700CS internal display controller supports Video Graphics Adapter (VGA)
functions on the internal display and Super VGA (SVGA) functions on the external
display.
❑TFT color LCD (T4700CT/T4800CT)
A high-resolution 9.5-inch full-color, Thin Film Transistor (TFT) color LCD displays
640x480 pixels.
The T4700CT/T4800CT internal display controller supports VGA functions on the
internal display and SVGA functions on the external display.
❑Keyboard
An easy-to-use 82/84-key enhanced keyboard with full-size keys and standard spacing
is compatible with IBM standard software.
❑Batteries
The T4700CS/T4700CT/T4800CT has three different batteries: a main battery, a
backup battery, and a Real Time Clock (RTC) battery.
❑Status indicator panel
The T4700CS/T4700CT/T4800CT has a status indicator panel. It is a liquid crystal
display (LCD) panel which displays battery charge indicator and 11 icons indicating
the system status.
❑Memory card slot
The T4700CS/T4700CT/T4800CT has one Toshiba optional memory card slot, which
enables you to install a Toshiba optional memory card.
❑Personal Computer Memory Card International Association (PCMCIA) card slot
The T4700CS/T4700CT/T4800CT has two PCMCIA slots, which enable you to
install a MiNC Toshiba card modem or other industry standard PCMCIA release 2.0
card.

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❑Expansion port
The T4700CS/T4700CT/T4800CT has one unique 150-pin expansion port, which
attaches to a Desk Station IV.
❑PRT/FDD port
T4700CS/T4700CT/T4800CT’s Centronics compatible parallel interface port serves
two purposes. The port can be used to connect a Centronics compatible printer or an
external 5.25-inch floppy disk drive.
❑RS-232C port
The T4700CS/T4700CT/T4800CT has one 9-pin serial interface port.
❑Mouse port
The T4700CS/T4700CT/T4800CT has one 6-pin mouse port on the back that can be
connected to an IBM PS/2 mouse.
❑Keyboard port
The T4700CS/T4700CT/T4800CT has one 6-pin keyboard port on the back that can
be connected to an IBM PS/2 keyboard.
❑Microsoft BallPoint mouse V2.0 with QuickPort connection (BPQP2)
The T4700CS/T4700CT/T4800CT has one BPQP2 port on the right.
❑RGB port
The T4700CS/T4700CT/T4800CT has one 15-pin RGB port on the back that can be
connected to an external video display.
❑Audio ports
• Headphone, standard 3.5 mm diameter miniature stereo jack with
speaker shutoff switch.
Use a headphone with an impedance of 16W.
• Microphone, standard 3.5 mm diameter miniature monaural jack.

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The T4700CS/T4700CT/T4800CT Personal Computer is shown in figure 1-1. The system
configuration is shown in figure 1-2.
Figure 1-1 T4700CS/T4700CT/T4800CT personal computer
Figure 1-2 T4700CS/T4700CT/T4800CT system unit configuration

T4700CS, T4700CT, T4800CT 1-5
1.2 System Unit Block Diagram
Figure 1-3 is a block diagram of the T4700CS/T4700CT/T4800CT system unit.
Figure 1-3 T4700CS/T4700CT/T4800CT system board block diagram

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The T4700CS/T4700CT/T4800CT system board shown in figure 1-3 is composed of the
following major components:
❑ A 486DX2-50 (T4700CS/T4700CT) CPU, which incorporates a math co-
processor and 8 KB cache memory.
A 486DX4-75 (T4800CT) CPU, which incorporates a math co-processor and
16 KB cache memory.
❑The following memory components:
Standard RAM: 8 MB, 32-bit data width (70 ns)
Cache memory: 8 KB (inside a 486DX2-50 CPU)
16 KB (inside a 486DX4-75 CPU)
System, Video, 128 KB (96 KB are used), 8-bit data width
BIOS: A 1-Mbit flash ROM is used (150 ns).
This ROM contains Initial Reliability Test (IRT), Basic Input/
Output System (BIOS), and video BIOS.
Video RAM: 1 MB, 16-bit data width.
Two 256Kx16 bit chips are used.
Memory card: 4, 8, or 16 MB memory card can be installed.
32-bit data width.
❑ Super Integration (SI) T9901, which stores the following components:
•Two Direct Memory Access Controllers (DMAC): 82C37
•Two Programmable Interrupt Controllers (PIC): 82C59
•One Programmable Interval Timer (PIT): 82C54
•One Floppy Disk Controller (FDC): TC8565
•One Serial Input/Output Controller (SIO): TC8570
•One Variable Frequency Oscillator (VFO): TC8568
•One I/O Controller
•One Printer Port Controller
•One Speaker Controller
❑ A Real Time Clock (RTC)
One T9934 chip is used. The T9934 has 128 of bytes memory. Fourteen bytes
memory are used for the calendar and clock. The remaining 114 bytes are used for the
system configuration data.
❑ A Keyboard Controller (KBC)
One M37452M4 chip is used.
This KBC includes the keyboard scan controller and keyboard interface controller.
The KBC controls the internal keyboard, external keyboard port, PS/2 mouse port,
and BPQP2 port.

T4700CS, T4700CT, T4800CT 1-7
❑VGA display controller: WD90C24A (208-pin)
This controller controls internal and external VGA compatible display and external
SVGA compatible display with Analog Digital Converter (DAC). It can display data
on the internal and external display at the same time and operates at 3.3 volts.
.
❑Sound Controller
One AD1848 chip is used. The AD1848 controls the internal sound system.
❑Clock Generator receives 14.31818 MHz (X1) and generates the following frequen-
cies:
•25 MHz for the CPU (CPU operates 50MHz[T4700CS/T4700CT] or
75MHz [T4800CT])
•14.7456 MHz for the COM
•24 MHz for the FDC and VFO
•16 MHz is used for GA
•14.31818 MHz for WD90C24A (for VGA)
OSC (X3) generates 32.768 KHz for RTC.
❑Gate Array
System Controller Gate Array
This gate array has following functions:
•CPU Controller
-SMI Controller
-CPU Clock Controller
•Memory Controller
-DRAM Controller
-Compatible Bus Interface Controller
•Bus Controller
-Compatible Bus Interface Controller
-Compatible Access Controller
-DMAC Controller
-I/O Controller
•Address Latch Controller
-32-Bit to 16-Bit Controller
-Address Latch
-DMA Address Generator
-Refresh Address Generator
•I/O Register
-Compatible I/O Port Register
-Saving the data of the Register (in resume) Controller
-Toshiba Special Register

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•Processing Speed Controller
•Data Latch
•Suspend/Resume Controller
Sub LCD Controller Gate Array
This gate array has following functions:
•Status Indicator Panel Controller
-LCD Segment Flashing Controller
•Internal Communication Controller
-KBC/Power Supply Micro Processor/Main CPU Communication
Controller
-KBC/Power Supply Micro Processor Interrupt Controller
IC Card Controller Gate Array
This gate array has following functions:
•IC Card Controller
-PCMCIA IC Card Controller
-Toshiba Modem Card Controller
•EEPROM (for security) Controller
-KBC-Security-EEPROM Communication Controller
•Others
-KBC Communication Controller
-Disable the PRT/FDD Port, HDD Access Controller
-EEPROM (for BIOS) Access Mode Controller
-Sound System Access Controller

T4700CS, T4700CT, T4800CT 1-9
1.3 3.5-inch Floppy Disk Drive
The T4700CS/T4700CT/T4800CT 3.5-inch Floppy Disk Drive (FDD) is a thin, high-perfor-
mance reliable drive that supports 720-KB (formatted) 2DD and 1.44-MB (formatted) 2HD
3.5-inch floppy disks.
The T4700CS/T4700CT/T4800CT FDD is shown in figure 1-4. The specifications for the
FDD are described in table 1-1.
Figure 1-4 3.5-inch FDD
Table 1-1 3.5-inch FDD specifications
Item 2-MB mode 1-MB mode
Storage capacity (KB)
Unformatted 2,000 1,000
Formatted 1,311 737
Number of heads 2 2
Number of cylinders 80 80
Access time (ms)
Track to track 3 3
Average 181 181
Head settling time 15 15
Recording track density (tpi) 135 135
Data transfer rate (Kbps) 500 250
Rotation speed (rpm) 300 300
Recording method Modified Frequency Modulation (MFM)

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1.4 2.5-inch Hard Disk Drive
The Hard Disk Drive (HDD) is a random access non-volatile storage device. It has a non-
removable 2.5-inch magnetic disk and mini-winchester type magnetic heads.
T4700CS/T4700CT supports the 200 MB and 320 MB. T4800CT supports the 320 MB and
500 MB.
The T4700CS/T4700CT/T4800CT HDD is shown in figure 1-5. Specifications for the HDD
are described in table 1-2.
Figure 1-5 2.5-Inch HDD
Table 1-2 2.5-inch HDD specifications
200 MB 320 MB 500 MB
(MK2224FC) (MK2326FC) (MK2428FC)
Storage capacity (MB)
Formatted 213.0 320.0 524.0
Number of disks 2 3 4
Data heads 4 6 8
Data surfaces 4 6 8
Track per surface 1,560 1,830 1,920
Bytes per sector 512 512 512
Access time (ms)
Track to track 3 3 3
Average 12 12 12
Maximum 25 25 25
Rotation speed (rpm) 4,000 4,200 4,000
Data transfer rate (bps)
To/from media 18.9 to 31.6 M 18.7 to 29.6 M 18.9 to 31.6 M
Interleave 1:1 1:1 1:1
Recording method 1-7 RLL 1-7 RLL 1-7 RLL

T4700CS, T4700CT, T4800CT 1-11
1.5 Keyboard
The 82-(USA) or 84-(European) keyboard is mounted on the T4700CS/T4700CT/
T4800CT’s system unit. The keyboard is connected to the keyboard controller on the system
board through a 19-pin flat cable. The keyboard is shown in figure 1-6.
See Appendix F for optional keyboard configurations.
Figure 1-6 Keyboard

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1.6 STN Color LCD
The STN Color Liquid Crystal Display (LCD) contains an LCD module, a Fluorescent Lamp
(FL), and an FL inverter board.
1.6.1 STN Color LCD Module
The T4700CS STN color LCD is backlit and supports 640x480 pixels with a Video control-
ler. This video controller includes the functions of Video Graphics Array (VGA).
The T4700CS’s LCD receives vertical and horizontal synchronizing signals, 16-bit data signal
(8-bit upper block data signal, 8-bit lower block data signal), display enable signal, and shift
clock for data transmission. All signals are CMOS-level compatible.
The STN LCD is shown in figure 1-7. The specifications for the LCD are described in table
1-3.
Figure 1-7 STN color LCD
Table 1-3 STN color LCD specifications
Item Specifications
Number of Dots (dots) 640x480
Dot pitch (mm) 0.3(W)x0.3(H)
Display area (mm) 195 (W)x147 (H)
Contrast 18:1 (Typically)
FL current (mA) 6.0
FL frequency (KHz) 47
NOTE: If ghost images remain on the screen after power is turned off, leave the
power off for a day and let the computer sit at room temperature. If the problem is
still not corrected, leave the computer at room temperature for two days or longer.

T4700CS, T4700CT, T4800CT 1-13
1.6.2 STN Color Fluorescent Lamp (FL) Inverter Board
The FL inverter board supplies high frequency current to light the LCD’s Fluorescent Lamp.
The specifications for the FL inverter are described in table 1-4.
Table 1-4 STN color FL inverter board specifications
Item Specifications
Input Voltage (VDC) 18
Power (W) 4.17
Output Voltage (VAC) 1,100
Current (mA) 6.0
Frequency (KHz) 47

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1.7 TFT Color LCD
The TFT Color Liquid Crystal Display (LCD) contains an LCD module, a Fluorescent Lamp
(FL), and an FL inverter board.
1.7.1 TFT Color LCD Module
The T4700CT/T4800CT TFT color LCD supports 640x480 pixels with an internal display
controller and 512 colors for graphics and characters. This controller includes the functions
of Video Graphics Array (VGA) and Super VGA (SVGA) for external display.
The T4700CT/T4800CT’s LCD receives 9-bit data signals, data enable signals, and shift clock
for data transmission. All signals are CMOS-level compatible.
The TFT LCD and FL invertor board are shown in figure 1-8. The specifications for the LCD
are described in table 1-5.
Figure 1-8 TFT color LCD
Table 1-5 TFT color LCD specifications
Item Specifications
Number of dots (dots) 640x480
Dot pitch (mm) 0.3 (W)x0.3 (H)
Display area (mm) 192 (W)x144 (H)
Contrast 60:1 (minimum)
FL current (mA) 6.0
FL frequency (KHz) 47

T4700CS, T4700CT, T4800CT 1-15
1.7.2 TFT Color Fluorescent Lamp (FL) Inverter Board
The FL inverter board supplies high frequency current to light the LCD’s Fluorescent Lamp.
The specifications for the FL inverter are described in table 1-6.
Table 1-6 FL inverter board specifications
Item Specifications
Input Voltage (VDC) 18
Power (W) 3
Output Voltage (VAC) 1,100
Current (mA) 6.0
Frequency (KHz) 47
Current limits (mA) 3.0 to 6.0

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1.8 Power Supply
The power supply supplies five kinds of voltages to the T4700CS/T4700CT/T4800CT
system board. The T4700CS/T4700CT/T4800CT power supply has one microprocessor and
it operates at 500 KHz (power off) or 20 MHz (power on). It contains the following func-
tions:
1. Determines if the AC adapter or battery is connected to the computer.
2. Detects DC output and circuit malfunctions.
3. Controls the speaker and the brightness.
4. Controls the Battery capacity icon, Power on icon and AC adapter icon on the
status indicator panel.
5. Turns the battery charging system on and off and detects a fully charged
battery.
6. Determines if the power can be turned on and off.
7. Provides more accurate detection of a low battery.
8. Calculates the remaining battery capacity.
The power supply output rating is specified in table 1-7.
Table 1-7 Power supply board output rating
DC Regulation Maximum
Use for Name voltage tolerance current Ripple
(V) (%) (mA) (mV)
System logic, FDD, HDD VCC +5 ±5 2,700 100
RS-232C, Flash ROM 12V +12 ±5 120 240
Display DSPV +9.5 to +23 –4.02 W –
RAM, CPU B3V +3.3 ±5 930 (T4700CS/T4700CT) 60
1,200 (T4800CT)
RS-232C M12V -7 to -12.6 _ 10 –

T4700CS, T4700CT, T4800CT 1-17
1.9 Batteries
The T4700CS/T4700CT/T4800CT has three types of batteries:
❑Main battery pack
❑Backup battery
❑Real Time Clock (RTC) battery
These batteries’ specifications are described in table 1-8.
Table 1-8 Batteries' specifications
Battery name Material Output voltage Capacity
Main battery Nickel Metal Hydride 12 V 2,400 mAh (T4700CS/T4700CT)
2,600 mAh (T4800CT)
Backup battery Nickel Metal Hydride 1.2 V 1,100 mAh
RTC battery Lithium-Vanadium 3.0 V 50 mAh
1.9.1 Main Battery
The removable main battery pack is the computer’s main power source when the AC adapter
is not attached. The backup and main battery maintain the state of the computer when you
enable AutoResume.

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1.9.2 Battery Charging Control
Battery charging is controlled by a power supply microprocessor that is mounted on the
power supply. The microprocessor controls whether the charge is on or off and detects a full
charge when the AC adapter and battery are attached to the computer. The system charges
the battery using quick charge or trickle charge.
NOTE: When the temperature difference between the computer and the battery
pack is more than 10°C, a full charge may be detected even if the battery is not full
charged. Remove the battery pack for about five minutes to let the computer
and battery reach the same temperature. Then, reinstall the battery pack.
❏Quick Battery Charge
When the AC adapter is attached, there are two types of quick charge: quick charge 1
when the system is powered off and quick charge 2 when the system is powered on.
Table 1-9 Time required for quick charges
Kind of battery Charging time
Quick charge 1 Nickel Metal Hydride About 1 hour, 30 minutes
(power off)
Quick charge 2 Nickel Metal Hydride 2 to 4 hours (typical: 3 hours)
(power on)
NOTES 1: The time required for quick charge 2 is affected by the amount of
power the system is consuming. Use of the fluorescent lamp and
frequent disk access diverts power and lengthens charge time.
2: Using quick charge 1, the system CPU automatically stops the
charge after two hours and twenty minutes regardless of the battery
condition.
If the one of the following occurs, the battery quick-charge process stops.
1. The battery becomes fully charged.
2. The AC adapter or battery is removed.
3. The battery or output voltage is abnormal.
❏Trickle Battery Charge
When the main battery is fully charged and the AC adapter is attached, the micropro-
cessor automatically changes quick charge 1 or 2 to trickle charge.

T4700CS, T4700CT, T4800CT 1-19
❏Detection of full charge
A full charge is detected only when the battery is charging at quick charge. A full
charge is detected under any of the following conditions:
1. A battery voltage fall is detected.
2. The charging time exceeds the fixed limit.
3. The thermal rise (+DT) exceeds the fixed limit.
4. The battery’s temperature is over 60°C.
1.9.3 Backup Battery
The backup battery maintains data for AutoResume. The power source used to back-up the
AutoResume data is determined according to the following priority:
AC adapter > Main battery > Backup battery
The backup battery is charged by the main battery or AC adapter when the system is powered
on. Table 1-10 shows the charging time and data preservation period of the backup battery.
Table 1-10 Backup battery charging/data preservation time
Time
Charging Time Power On 20 H
Power Off 75 H
Data preservation period (full charge) 8.0 H
1.9.4 RTC battery
The RTC battery provides power to keep the current date, time and other setup information in
memory while the computer is turned off. Table 1-11 shows the charging time and data
preservation period of the RTC battery.
Table 1-11 RTC battery charging/data preservation time
Time
Charging Time Power On 24 H
Power Off 24 H
Data preservation period (full charge) 1 month

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