Toshiba T6400 User manual

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Chapter 1
HardwareOverview

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Contents
1.1 General................................................................................................................................1-5
1.2 System Unit Block Diagram................................................................................................1-8
1.3 3.5-inch Floppy Disk Drive ............................................................................................... 1-10
1.4 3.5-inch Hard Disk Drive .................................................................................................. 1-11
1.5 Keyboard........................................................................................................................... 1-12
1.6 Gas Plasma Display........................................................................................................... 1-13
1.7 Color Liquid Crystal Display ............................................................................................ 1-14
1.8 Power Supply Unit ............................................................................................................ 1-15
Figures
Figure 1-1 T6400 system unit..................................................................................................... 1-7
Figure 1-2 Block diagram........................................................................................................... 1-8
Figure 1-3 3.5-inch FDD .......................................................................................................... 1-10
Figure 1-4 3.5-inch HDD.......................................................................................................... 1-11
Figure 1-5 Keyboard................................................................................................................. 1-12
Figure 1-6 Gas plasma display ................................................................................................. 1-13
Figure 1-7 Color LCD .............................................................................................................. 1-14
Figure 1-8 Power supply unit ................................................................................................... 1-15
Tables
Table 1-1 T6400 models ...........................................................................................................1-5
Table 1-2 3.5-inch FDD specifications.................................................................................... 1-10
Table 1-3 3.5-inch HDD specifications ................................................................................... 1-11
Table 1-4 Gas plasma display specifications........................................................................... 1-13
Table 1-5 Color LCD specifications........................................................................................ 1-14
Table 1-6 Power supply unit output ratings............................................................................. 1-15

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1.1 General
The Toshiba T6400 is one of the lightest and most advanced portable computers available. Utiliz-
ing advanced technology and high speed components, the T6400 offers excellent display legibility
and IBM PC/AT compatibility.
There are four models of the T6400 depending on the CPU, display type, and HDD capacity. Refer
to Table 1-1 below.
Table 1-1 T6400 models
The T6400 system unit consists of the following features:
Microprocessor The T6400 model uses an 80486SX-25 microprocessor that operates at 25
MHz.
The T6400DX model uses an 80486DX-33 microprocessor that operates at
33 MHz.
Math co-processor The T6400DX model has a Numeric Data Processor (NDP) inside the CPU.
The T6400 comes with a built-in socket for an 80486DX-33 which incorpo-
rates a Numeric Data Processing Unit (NDP).
Cache memory The T6400 has an 8 KB cache memory which is stored in the microproces-
sor.
Disk storage The T6400 has an internal 120 or 200 Megabyte (MB) Hard Disk Drive
(HDD) with an average access time of 19 milliseconds. A 3.5-inch Floppy
Disk Drive (FDD) supports 2HD floppy disks (1.44 Mbytes) and 2DD
floppy disks (720 Kbytes).
CPU Display TypeHDD capacity(MB)
Intel
80486DX-33
PDP200
TFT200
Intel
80486SX-25
PDP120
TFT120
UPDATE

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Memory The T6400 comes standard with 4 MB of CMOS Random Access Memory
(RAM). This includes 640 KB of conventional memory and 3456 KB of
extended memory which can be utilized as expanded memory compatible
with the Lotus/Intel/Microsoft Expanded Memory Specifications (LIM-
EMS).
Display The T6400 has two types of internal displays. They are an active matrix
Thin Film Transistor (TFT) type color Liquid Crystal Display (LCD)
640x480 pixels, and a high resolution Plasma Display (PDP) 640x480
pixels with a 16-level gray scale.
The T6400 internal display controller supports Video Graphics Adapter
(VGA) functions on the internal display devices.
Keyboard The detachable easy-to-use 101/102-key keyboard with full size keys and
standard spacing is compatible with IBM standard software.
Power supply The universal auto-sensing power supply enables world-wide usage of the
T6400 as long as a compatible AC plug is available.
Battery The one Real Time Clock (RTC) battery keeps the date and time in addi-
tion to the system configuration parameters even if the system is powered
off.
Expansion slot The T6400 expansion slot is used to enhance the T6400 capabilities with
various ISA adapter cards, which fit in one 8-bit or 16-bit full-size industry
standard slot.
Parallel port A Centronics-compatible parallel interface port serves two purposes. The
port can be used to connect a Centronics-compatible printer or an external
floppy disk drive.
RS-232-C port The T6400 has one 9-pin serial interface port.
Keyboard port The T6400 has an external PS/2 keyboard interface port on the right side.
Mouse port The T6400 has one 6-pin mouse port on the back that can be used for
connecting a PS/2 mouse.
RGB port The T6400 has one 15-pin RGB port on the back that can be used for
connecting an external video display.
Ext. 3.5" FDD port The 26-pin FDD interface port allows you to connect the optional Toshiba
external 3.5" FDD unit.
Built-in modem port A Toshiba built-in modem can be installed inside the T6400.

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Expansion port The 150-pin expansion bus connector port allows you to connect unique
optional Toshiba devices.
Memory slots The T6400 has two expansion memory slots for installing the optional 2, 4,
and/or 8 MByte memory cards.
The T6400 Personal Computer is shown in Figure 1-1.
Figure 1-1 T6400 system unit

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1.2 System Unit Block Diagram
Figure 1-2 is a block diagram of the T6400 system unit.
Figure 1-2 Block diagram

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The T6400 system board shown in Figure 1-2 is composed of the following major components:
❑An 80486DX-33 or 80486SX-25 CPU
❑Super Integration (SI) T9901 (208-pin), which stores the following components:
●Two Direct Memory Access Controllers (DMACs): 82C37
●Two Programmable Interrupt Controllers (PICs): 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
❑A Real Time Clock (RTC): 146818AF
❑A Keyboard Controller (KBC): 80C42
❑Memory:
Standard RAM: 4 MB
Cache memory: 8 KB (inside CPU)
BIOS ROM: 1 MB
This ROM contains the Initial Reliability Test (IRT), Basic Input/Output
System (BIOS), and video BIOS.
Video RAM: 256 KB
Optional memory cards expand memory to a maximum of 20 MB.
❑System controller gate array: SYS CNT-GA (240-pin)
❑VGA display controller: PVGA1F: WD90C23 (132-pin)
❑Color gray scale controller
gate array: CGSC-GA (60-pin)
❑Digital analog converter: DAC (80-pin)
❑The following Oscillators (OSC):
X1: 33.34 MHz or 25.0 MHz OSC is used for the CPU
X5: 14.31818 MHz OSC is used for the KBC
X6: 14.7456 MHz OSC is used for the SIO
X7: 24 MHz OSC is used for the FDC and VFO
X9: 44.9 MHz OSC is used for the display controller
X901: 28.322 MHz OSC is used for the display controller
X902: 25.175 MHz OSC is used for the display controller
X903: 32.768 KHz OSC is used for the RTC
X904: 36.0 MHz OSC is used for the display controller

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1.3 3.5-inch Floppy Disk Drive
The T6400 3.5-inch Floppy Disk Drive (FDD) is a thin, high-performance, reliable drive that
supports 720KB (formatted) 2DD and 1.44MB (formatted) 2HD 3.5-inch floppy disks.
The T6400 FDD is shown in Figure 1-3 and its specifications are described in Table 1-2.
Figure 1-3 3.5-inch FDD
Item2-Mbytemode1-Mbytemode
Storagecapacity(Kbyte)
Unformatted
Formatted2,000
1,475 1,000 737
Numberofheads2 2
Numberofcylinders80 80
Access time(ms)
Tracktotrack
Average
Headsettling time
3
94
15
3
94
15
Recording trackdensity(tpi)135 135
Datatransferrate(Kbps)500 250
Rotation speed(rpm)300 300
Recording method ModifiedFrequencyModulation (MFM)

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Table 1-2 3.5-inch FDD specifications
1.4 3.5-inch Hard Disk Drive
The T6400 120MB or 200MB (formatted) Hard Disk Drive (HDD) is a random access, non-volatile
storage device. It has a non-removable 3.5-inch magnetic disk and mini-Winchester type magnetic
heads.
The T6400 HDD is shown in Figure 1-4. Specifications for the HDD are described in Table 1-3.
Figure 1-4 3.5-inch HDD
Item200MB(CP-30204)120MB(CP-30104)
Storagecapacity
Formatted(MB)212.6 121.5
Numberofdisks2 2
Dataheads4 4
Datasurfaces4 4
Trackspersurface 2,119 1,522
Sectorspertrack 49 39 (+1)
Bytespersector512 512
Access time(ms)
Tracktotrack
Average
Maximum
3
12
30
8
19
40
Rotation speed(rpm)4,498 3,400
Datatransferrate(MB/S)
To/frommedia2.5M1.5M
Interleave1:1 1:1
Recording method 2-7RLL/
1
-
7 RLL 2-7RLL/
1
-
7 RLL

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Table 1-3 3.5-inch HDD specifications
1.5 Keyboard
The 101-key (USA) or 102-key (European) keyboard is mounted on the T6400’s system unit. The
keyboard is connected to the keyboard controller in the keyboard unit. The keyboard is shown in
Figure 1-5.
See Appendix E for optional keyboard configurations.
Figure 1-5 Keyboard

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1.6 Gas Plasma Display
The gas plasma display is composed of a display panel and driver circuits. It receives vertical and
horizontal synchronizing signals, four-bit data signals, and shift clock for data transmission. All
signals are TTL-level compatible. The display has 16 levels of gray scale and the display quality
can be adjusted with the contrast control.
The gas plasma display is shown in Figure 1-6 and its specifications are described in Table 1-4.
Figure 1-6 Gas plasma display
ItemSpecifications
Numberofdots(dots)640 x 480
Dotpitch(mm)0.33 (W)x0.33 (H)
Displayarea (mm)158.4(W)x211.2(H)
ColorNeon-Orange
Contrastratio 100:1
Grayscale16 levels
Power(maximum)20 watts
Meantimebetweenfailure(MTBF) (hours)20,000

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Table 1-4 Gas plasma display specifications
1.7 Color Liquid Crystal Display
The color liquid crystal display (LCD) is composed of an LCD module, fluorescent lamps (FLs),
and an FL inverter board. The thin film transistor (TFT) LCD is illuminated from the back. Thus,
you can read its display clearly even in poorly lit conditions. It receives vertical and horizontal
synchronizing signals, 9-bit data signals, and shift clock signals for data transmission. All signals
are TTL-level compatible. The LCD specifications are described in Table 1-5.
The LCD has 512-color capability. The high frequency current is supplied by the FL inverter board
to illuminate the FLs. The color LCD is shown in Figure 1-7.
Figure 1-7 Color LCD
ItemSpecifications
Numberofdots(dots)640 x480
Dotpitch(mm)0.33 (W)x0.33 (H)
Displayarea (mm)211.2(W)x158.4(H)
Color512 colors
Contrastratio 60:1
Grayscale8levelsforeachgun (RGB)
Power(maximum)19 watts

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Table 1-5 Color LCD specifications
1.8 Power Supply Unit
The universal auto-sensing power supply can be used world-wide and supplies +5, -5, +12, and -12
VDC to the system.
The power supply unit is housed in the system unit and it supplies regulated power to the:
●System board
●Memory board
●3.5-inch floppy disk drive (FDD)
●3.5-inch hard disk drive (HDD)
●External keyboard
●Liquid crystal display (LCD) or plasma display (PDP)
●Option boards
●Cooling fans
The power supply unit includes an input line filter, line fuse, cooling fans, power conversion
circuitry, and connectors.
Input ratings are: 115 VAC, 1.5 A or 230 VAC, 1.0 A
The power supply unit is shown in Figure 1-8 and the output ratings are specified in Table 1-6.
Figure 1-8 Power supply unit
Table 1-6 Power supply unit output ratings
DC voltage(V)Maximumcurrent(A)
Forsystem
+5 6.09
+12 0.9(1.32)
-50.15
-12 0.25
+24 20 (17)

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Chapter 2
TroubleshootingProcedures

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Contents
2.1 T6400 Troubleshooting........................................................................................................ 2-5
2.2 Troubleshooting Flowchart ..................................................................................................2-6
2.3 Power Supply Unit Troubleshooting Procedures .................................................................. 2-8
Procedure 1 AC Cord Check..............................................................................................2-9
Procedure 2 Connector Check ......................................................................................... 2-10
Procedure 3 Output Voltage Check ................................................................................. 2-11
2.4 System Board Troubleshooting Procedures........................................................................ 2-12
Procedure 1 Message Check............................................................................................ 2-13
Procedure 2 Printer Port LED Check ............................................................................... 2-15
Procedure 3 Diagnostic Test Program Execution Check.................................................. 2-19
2.5 Floppy Disk Drive Troubleshooting Procedures................................................................. 2-20
Procedure 1 FDD Head Cleaning Check .......................................................................... 2-21
Procedure 2 External 5-1/4" FDD Check ......................................................................... 2-22
Procedure 3 Diagnostic Test Program Execution Check.................................................. 2-23
Procedure 4 Connector and Replacement Check ............................................................. 2-24
2.6 Hard Disk Drive Troubleshooting Procedures.................................................................... 2-25
Procedure 1 Message Check............................................................................................ 2-26
Procedure 2 Partition Check............................................................................................ 2-27
Procedure 3 Format Check .............................................................................................. 2-28
Procedure 4 Diagnostic Test Program Execution and Replacement Check...................... 2-29
2.7 Keyboard Troubleshooting Procedures .............................................................................. 2-30
Procedure 1 Diagnostic Test Program Execution Check.................................................. 2-31
Procedure 2 Connector and Replacement Check ............................................................. 2-32
2.8 Display Troubleshooting Procedures ................................................................................. 2-33
Procedure 1 Brightness Volume Check (for Plasma Type).............................................. 2-34
Procedure 2 External CRT Check .................................................................................... 2-35
Procedure 3 Diagnostic Test Program Execution Check.................................................. 2-36
Procedure 4 Connector Check ......................................................................................... 2-37
Procedure 5 Replacement Check ..................................................................................... 2-38
Tables
Table 2-1 Output voltages........................................................................................................ 2-11
Table 2-2 Printer port LED test status...................................................................................... 2-16
Table 2-3 Floppy disk drive error codes and status .................................................................. 2-23
Table 2-4 Hard disk drive error codes and statuses .................................................................. 2-28
Figures
Figure 2-1 Troubleshooting flowchart.........................................................................................2-6
Figure 2-2 Printer port LED ...................................................................................................... 2-15

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