Toshiba T3400 User manual

T3400/T3400CT Maintenance Manual
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1.1 Features
The Toshiba T3400/T3400CT is one of the lightest and most advanced portable computers
available. Utilizing advanced technology and high-speed components, the T3400/T3400CT
offers excellent display legibility, battery operation and IBM PC/AT compatibility. The
T3400/T3400CT system unit consists of the following features:
❑Microprocessor
The T3400/T3400CT uses an SL Enhanced Intel 486SX-33 microprocessor that
operates at 33 MHz, 3.3 Volts.
❑Cache memory
The T3400/T3400CT has an 8 Kilobyte (KB) cache memory stored in the i486SX
microprocessor.
❑Disk storage
The T3400/T3400CT has an internal 120 Megabyte (MB) Hard Disk Drive (HDD)
with an average access time of 17 milliseconds. An external 3.5-inch Floppy Disk
Drive (FDD) supports 2HD floppy disks (1.44 MB) and 2DD floppy disks (720 KB).
❑Memory
The T3400/T3400CT comes standard with 4 MB of CMOS Random-Access Memory
(RAM) 3.3 Volts. This includes 640 KB of conventional memory and 3,456 KB of
extended memory which can be utilized as expanded memory compatible with Lotus/
Intel/Microsoft-Expanded Memory Specifications (LIM-EMS).
❑Monochrome LCD (T3400)
A high-resolution, Liquid Crystal Display (LCD) displays 640 x480 pixels with a
64-level gray scale.
The T3400 internal display controller supports Video Graphics Array (VGA) func-
tions on the internal display and Super VGA (SVGA) functions on the external
display.
❑TFT color LCD (T3400CT)
A high-resolution, Thin-Film Transistor (TFT) full-color LCD displays 640 x 480
pixels. The T3400CT internal display controller supports VGA functions for internal
display and Super VGA (SVGA) functions for external display.
❑Keyboard
An easy-to-use 82/84-key keyboard includes a keypad overlay for fast numeric data
entry or cursor and page control. The computer keyboard supports software that uses
a 101- or 102-key enhanced keyboard.

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T3400/T3400CT Maintenance Manual
❑Batteries
The T3400/T3400CT has three batteries: a main battery, backup battery, and Real-
Time Clock (RTC) battery.
❑Personal Computer Memory Card International Association (PCMCIA) card slot
The T3400/T3400CT has one PCMCIA slot for installation of an MiNC Toshiba card
modem or other industry-standard PCMCIA release 2.0 card.
❑Parallel port
The T3400/T3400CT 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 T3400/T3400CT has one 9-pin serial interface port.
❑External 3.5-inch FDD port
The T3400/T3400CT has one external 3.5-inch FDD port.
❑Port replicator port
The T3400/T3400CT has one port replicator port which enables connection of an
optional port replicator or external monitor adapter. The port replicator allows
connection of an optional PS/2 keyboard, PS/2 mouse, and external monitor.
❑Memory module slot
The T3400/T3400CT has one slot for optional installation of a Toshiba memory
module.
❑Accupoint
The T3400/T3400CT has a pointer control stick in the center of the keyboard.

T3400/T3400CT Maintenance Manual
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The T3400/T3400CT Personal Computer is shown in Figure 1-1. T3400/T3400CT system
configuration is shown in Figure 1-2.
Figure 1-1 T3400/T3400CT Personal Computer
Figure 1-2 T3400/T3400CT System Unit Configuration

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T3400/T3400CT Maintenance Manual
1.2 System Unit Block Diagram
Figure 1-3 is a block diagram of the T3400/T3400CT system unit.
Figure 1-3 T3400/T3400CT System Board Block Diagram

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The T3400/T3400CT system board includes the following major components:
❑i486SX-33 CPU
❑Super Integration (SI) T9901 Gate Array (GA), which houses the following:
•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 Input/Output (I/O) Controller
•One Printer Port Controller
•One Speaker Controller
❑RTC
One T9934 chip with 128 bytes of memory is used. Fourteen bytes of memory are
used for the calendar and clock, and the remaining 114 bytes for system configura-
tion data.
OSC (X2) generates 32.768 KHz for the RTC.
❑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, Accupoint
(pointer control stick), external keyboard, and PS/2 mouse.
❑The following memories:
Standard RAM: 4 MB
Cache memory: 8 KB (inside CPU)
BIOS ROM: 128 KB (96 KB are used)
This ROM contains Initial Reliability Test (IRT), Basic
Input Output System (BIOS), and video BIOS.
Video RAM: 256 KB
Optional cards can be used to expand memory to a maximum of 20 MB.
❑VGA display controller (WD90C24)
This controller controls the internal VGA display and external SVGA- compatible
display.

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T3400/T3400CT Maintenance Manual
❑Clock Generator receives 14.31818 MHz (X3) and generates the following frequen-
cies:
•33 MHz for the CPU
•14.7477 MHz for the Communications (COM) port
•24 MHz for the FDC and VFO
•16 MHz is used for system controller GA
•14.31818 MHz is used for the SI T9901 GA
❑Gate Arrays
System Controller GA
This GA has the following functions:
•CPU Controller
•Memory Controller
-DRAM Controller
-Compatible Bus Interface Controller
•SMI Controller
•VL Bus Controller
•Bus Controller
-Compatible Bus Interface Controller
-Compatible Access Controller
-DMAC Controller
-I/O Controller
•Address Latch Controller
-32 to 16-Bit Controller
-Address Latch
-DMA Address Generator
-Refresh Address Generator
•I/O Register
-Compatible I/O Port
-Saving Register Controller data in AutoResume (resume mode)
-Toshiba Special Register
•Processing Speed Controller
•Data Bus Change Controller
•Data Latch
PCMCIA Controller GA
This GA has the following functions:
•Memory Card Controller
-PCMCIA IC Card Controller
-Toshiba Modem Card Controller

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1.3 External 3.5-inch Floppy Disk Drive
The 3.5-inch FDD is a thin, high-performance, reliable drive that supports 720-KB (format-
ted) 2DD and 1.44-MB (formatted) 2HD 3.5-inch floppy disks.
The FDD is shown in Figure 1-4. Specifications for the FDD are provided 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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T3400/T3400CT Maintenance Manual
1.4 2.5-inch Hard Disk Drive
The 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.
The T3400/T3400CT supports a 120 MB HDD.
The HDD is shown in Figure 1-5. Specifications for the HDD are provided in Table 1-2.
Figure 1-5 2.5-inch HDD
Table 1-2 2.5-inch HDD Specifications
Items (CP2124) (MK2124FC)
Storage capacity (MB)
Formatted 121.6 130.1
Number of disks 2 2
Data heads 4 4
Data surfaces 4 4
Tracks per surface 1,123 1,155
Sectors per track 53 (+1) 55 (+1)
Bytes per sector 512 512
Access time (ms)
Track to track 10 5
Average 17 17
Maximum 35 36
Rotation speed (rpm) 3,743 3,200
Data transfer rate (bps)
To/from media 18 M 15.3 M
Interleave 1:1 1:1
Recording method 2-7 RLL/ 1-7 RLL
1-7 RLL

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1.5 Keyboard
The 82-key (USA) or 84-key (European) keyboard is mounted on the system unit. The
keyboard is connected to the KBC on the system board via a 19-pin flat cable. The keyboard
is shown in Figure 1-6.
See Appendix F for optional configurations.
Figure 1-6 Keyboard

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T3400/T3400CT Maintenance Manual
1.6 Monochrome LCD
The monochrome LCD is composed of an LCD module, a Fluorescent Lamp (FL), and an
FL inverter board.
1.6.1 Monochrome LCD Module
The T3400 monochrome LCD supports 640 x480 pixels with a video controller and 64
levels of gray. The video controller includes the functions of the VGA and SVGA.
The LCD receives vertical and horizontal synchronizing signals, 8-bit data signals (4-bit
upper block data signal and 4-bit lower block data signal), and shift clock for data transmis-
sion. All signals are CMOS-level compatible.
The sidelit LCD is shown in Figure 1-7 and its specifications are provided in Table 1-3.
Figure 1-7 Monochrome LCD
Table 1-3 Monochrome LCD Specifications
Item Specifications
Number of dots (dots) 640 x 480
Dot pitch (mm) 0.24 (W) x 0.24 (H)
Display area (mm) 176.8 (W) x 132.6 (H)
Contrast 18:1 (typically)
FL current (mA) 4.0 (full-power mode)
FL frequency (KHz) 44