Toshiba T1950 User manual

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1.1 Features
The T1950, T1950CS and T1950CT units consist of the following features.
Processor Intel SL-Enhanced 486DX2/40Mhz. (P24S chip)
Processor Type DX2: (3.3v w/8KB internal cache) Co-processor embedded.
BIOS 128KB flash EPROM (150ns)
RAM 4MB Expandable to 20MB (80ns)
Display T1950: Fluorescent Sidelit Monochrome LCD
T1950CS: Dynamic-STN Dual Scan Color LCD
T1950CT: TFT Active Matrix Color LCD
Ext. Display T1950 & T1950CS: VGA 640 x 480 (16 colors of 4096)
T1950CT: 800 x 600/256 colors;1024 x 768/256 colors
(using Toshiba supplied drivers)
FDD 3 1/2" 1.44MB
HDD T1950 & T1950CS: 120MB/200MB
T1950CT: 200MB/320MB
Optional Peripherals 101-key Keyboard (PS/2)
1 - 14.5mm PCMCIA Type III (2.0)
Ports 19-PIN Serial (16450 UART)
1Parallel/FDD: BI-DIR
115-PIN RGB
1Mouse Quick Port (DCBM)
1PS/2 Mouse Port (not usable if DCBM connected)
Keyboard 1101-key Keyboard Port (PS/2)
82-Keys, 3mm Travel
Battery NIMH (12V 2400mAH) PART# PA2420UXRA
Battery Life 2-3 HRS.
Recharge Time 1.4-2.3 HRS (Computer off only)
AC Adapter T1950 & T1950CS: Input: 100-240VAC , Input Frequency:
50-60Hz, Input Power: .5A - .28A (50/60Hz)
Output Voltage: 18 VDC, 1.1A
T1950CT: Input: 100-240VAC, Input Frequency: 50-60Hz,
Input Power: .7A - .4A (50/60Hz)
Output Voltage: 18 VDC, 1.7 A
Bundled Software Toshiba DOS 6.0; Windows 3.1; MaxTime; Ultrafont.
Dimensions T1950: 11.7"W x 8.4"D x 2.0"H, 6.4 lbs.
T1950CS & T1950CT: 11.7"W x 8.4"D x 2.1"H, 7 lbs.

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The T1950 Series Personal Computer is shown in Figure 1-1, and its system configuration is
shown in Figure 1-2.
Figure 1-1 T1950 Series Personal Computer
Figure 1-2 T1950 Series System Unit Configuration

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1.2 System Unit Block Diagram
Figure 1-3 is a block diagram of the T1950 Series system unit.
Figure 1-3 T1950 Series System Board Block Diagram

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The T1950 Series system board is composed of the following major components:
❑An i486DX2-40 CPU
❑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 of
memory are used for the calendar and clock. The remaining 114 bytes are used for the
system configuration data.
OSC (X3) generates 32.768 KHz for RTC.
❑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 Ball Point Quick Port.
❑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 memory cards expand memory to a maximum of 20 MB.
❑VGA display controller
T1950/T1950CS (GOGH): This controller controls internal and external VGA com-
patible display.
T1950CT (WD90C24): This controller controls internal VGA display and external
SVGA compatible display.

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❑Clock Generator receives 14.31818 MHz (X2) and generates the following frequen-
cies:
•20 MHz for the CPU (CPU operates at 40MHz.)
•14.7456 MHz for the COM
•24 MHz for the FDC and VFO
•16 MHz is used for GA
•14.31818 MHz is used for T9901 (SI)
❑Gate Array
System Controller Gate Array
This gate array 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-Bit to 16-Bit Controller
-Address Latch
-DMA Address Generator
-Refresh Address Generator
•I/O Register
-Compatible I/O Port
-Saving the data of the Register (in resume) Controller
-Toshiba Special Register
•40 MHz/20 MHz Controller
•Data Bus Change Controller
•Data Latch
PCMCIA Controller Gate Array
This gate array has the following functions:
•Memory Card Controller
-PCMCIA IC Card Controller
-Toshiba Modem Card Controller

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1.3 3.5-inch Floppy Disk Drive
The T1950 Series 3.5-inch Floppy Disk Drive (FDD) is a thin, high-performance reliable drive
that supports 720-KB (formatted) 2DD and 1.44-MB (formatted) 2HD 3.5-inch floppy disks.
The T1950 Series FDD is shown in Figure 1-4, and specifications are listed 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.
The T1950/T1950CS supports a 120 or 200 MB HDD. The T1950CT supports a 200 or
320 MB HDD.
A T1950 Series HDD is shown in Figure 1-5, and specifications are listed in Table 1-2.
Figure 1-5 2.5-inch HDD
Table 1-2 2.5-inch HDD Specifications
120 MB 200 MB 320 MB
(CP2124) (MK2124FC) (MK2224FC) (MK2326FC)
Storage capacity (MB)
Formatted 121.6 130.1 213.0 340.0
Number of disks 2 2 2 3
Data heads 4 4 4 6
Data surfaces 4 4 4 6
Tracks per surface 1,123 1,155 1,560 1,830
Sectors per track 53 (+1) 55 (+1) – –
Bytes per sector 512 512 512 512
Access time (ms)
Track to track 3 5 3 3
Average 16 17 12 12
Maximum 30 36 25 25
Rotation speed (rpm) 3,743 3,200 4,000 4,200
Data transfer rate (bps)
To/from media 18 M 15.3 M 18.9 to 18.7 to
31.6 M 29.6 M
Interleave 1:1 1:1 1:1 1:1
Recording method 2-7 RLL 1-7 RLL 1-7 RLL 1-7 RLL

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1.5 Keyboard
The 82-(USA) or 84-(European) keyboard is mounted on the T1950 Series system unit, and is
connected to the keyboard controller on the system board through a 19-pin flat cable. The
keyboard is shown in Figure 1-6.
Figure 1-6 Keyboard

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1.6 Monochrome LCD (T1950)
The monochrome Liquid Crystal Display (LCD) is composed of an LCD module, a Fluores-
cent Lamp (FL), and an FL inverter board.
1.6.1 Monochrome LCD Module
The T1950 monochrome LCD supports 640x480 pixels with a Video controller and 64 levels
of gray. The video controller includes the functions of the Video Graphics Array (VGA).
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 transmission. All
signals are CMOS-level compatible.
The sidelit LCD is shown in Figure 1-7, and its specifications are listed 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) 0.30 (W) x 0.30 (H)
Display area (mm) 198 (W) x 150 (H)
Contrast 17:1 (typically)
FL current (mA) 5.0
FL frequency (KHz) 42

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1.6.2 Monochrome Fluorescent Lamp (FL) Inverter Board
The FL inverter board supplies the high frequency current needed to illuminate the FL.
The specifications for the FL inverter board are listed in Table 1-4.
Table 1-4 Monochrome FL Inverter Board Specifications
Item Specifications
Input Voltage (VDC) 5
Power (W) 2.2
Voltage (VAC) 950
Output Current (mA) 4.2
Frequency (KHz) 38.5

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1.7 STN Color LCD (T1950CS)
The STN Color Liquid Crystal Display (LCD) contains an LCD module, a Fluorescent Lamp
(FL), and an FL inverter board.
1.7.1 STN Color LCD Module
The T1950CS 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 T1950CS’s LCD receives vertical and horizontal synchronizing signals, 16-bit data signal
(8-bit upper block data signal and 8-bit lower block data signal) and shift clock for data
transmission. All signals are CMOS-level compatible.
The STN LCD is shown in Figure 1-8, and specifications for the LCD are listed in Table 1-5.
Figure 1-8 STN Color LCD
Table 1-5 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) 5.0
FL frequency (KHz) 47

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1.7.2 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 listed in Table 1-6.
Table 1-6 STN Color FL Inverter Board Specifications
Item Specifications
Input Voltage (VDC) 5
Power (W) 6
Output Voltage (VAC) 1,000
Current (mA) 5.0 x 2
Frequency (KHz) 42

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1.8 TFT Color LCD (T1950CT)
The TFT Color Liquid Crystal Display (LCD) contains an LCD module, a Fluorescent Lamp
(FL), and an FL inverter board.
1.8.1 TFT Color LCD Module
The T1950CT 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 T1950CT’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 is shown in Figure 1-9, and specifications are listed in Table 1-7.
Figure 1-9 TFT Color LCD
Table 1-7 TFT Color LCD Specifications
Item Specifications
Number of dots (dots) 640x480
Dot pitch (mm) 0.27 (W)x0.27 (H)
Display area (mm) 171 (W)x130 (H)
Contrast 60:1 (minimum)
FL current (mA) 5.0
FL frequency (KHz) 47

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1.8.2 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 listed in Table 1-8.
Table 1-8 FL Inverter Board Specifications
Item Specifications
Input Voltage (VDC) 5
Power (W) 3
Output Voltage (VAC) 1,100
Current (mA) 5.0
Frequency (KHz) 47

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1.9 Power Supply
The power supply uses a microprocessor to monitor and regulate the voltages used within the
T1950 Series computers. The power supply contains the following functions:
1. Determines if the AC adapter or battery is connected to the computer.
2. Detects DC output and circuit malfunctions.
3. Controls the LED indicator and speaker.
4. Turns the battery charging system on and off and detects a fully charged
battery.
5. Determines if the power can be turned on and off.
6. Provides more accurate detection of a low battery.
7. Calculates the remaining battery capacity.
The power supply output rating is specified in Table 1-9.
Table 1-9 Power Supply Output Rating
DC Regulation Maximum
Use for Name voltage tolerance current Ripple
(V) (%) (mA) (mV)
System logic, FDD, HDD, VCC +5 ±5 3,500 100
Display
RS-232C, Flash ROM 12V +12 ±5 120 240
RAM, CPU B3V +3.3 ±5 755 66
RS-232C M12V –7 to –12.6 – 10 –

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1.10 Batteries
The T1950 Series has three types of batteries:
❑Main battery pack
❑Backup battery
❑Real Time Clock (RTC) battery
Specifications for these batteries are listed in Table 1-10.
Table 1-10 Battery Specifications
Battery name Material Output voltage Capacity
Main battery Nickel Metal Hydride 12 V 2,400 mAH
Backup battery Nickel Metal Hydride 1.2 V 1,100 mAH
RTC battery Lithium-Vanadium 3.0 V 50 mAH
1.10.1 Battery Indicator
The battery indicator is located on the top cover, and shows the status of the removable
battery pack, power supply and AC adapter.
The status of each can be determined by color:
Orange The battery is being charged. (AC adapter is attached.)
Green The battery is fully charged. (AC adapter is attached.)
No light The AC adapter is disconnected from the computer or the AC adapter is
connected, but it cannot charge the battery for one of the following reasons:
❍The battery is extremely hot. Allow the computer and the battery to
reach room temperature before attempting to charge the battery.
❍The battery is almost fully discharged. The battery will not begin
charging immediately in this state, it will begin charging a few
minutes after the AC adapter is connected.
❍The AC adapter is not receiving power.
1.10.2 Main Battery
The removable main battery pack is the computer’s main power source when the AC adapter
is not attached. The main battery recharges the backup battery when the system’s power is
on. The backup and main battery maintain the state of the computer when you enable
AutoResume, and they maintain the information in Hard RAM.

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1.10.2.1 Battery Charging Control
Battery charging is controlled by a 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.
When the AC adapter is attached, there are two types of charge: quick charge when the
system is powered off, and trickle charge when the system is powered on. Table 1-11 shows
the charging time period of the main battery.
Table 1-11 Time Required for Battery Charges
Charging time
Quick charge About 2.3 hours (T1950)
(power off) About 1.4 hours (T1950CS/T1950CT)
Trickle charge About 48 hours
(power on)
❏Quick Battery Charge
If 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 AC adapter output voltage is abnormal.
4. The charge current is abnormal.
❏Trickle Battery Charge
When the main battery is fully charged and the AC adapter is attached, the power supply
microprocessor automatically changes quick charge to trickle charge.
1.10.3 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 1-12 shows the charging time and data preservation period of the backup battery.

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Table 1-12 Backup Battery Charging/Data Preservation Time
Time
Charging Time Power On 16 H
Power Off (with AC Adapter) 60 H
Power Off (Without AC Adapter) Doesn’t charge
Data preservation period (full charge) 8 H
1.10.4 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 1-13 shows the charging time and data
preservation period of the RTC battery.
Table 1-13 RTC Battery Charging/Data Preservation Time
Time
Charging Time Power On 48 H
Power Off Doesn’t charge
Data preservation period (full charge) 1 month

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2.1 Troubleshooting
Chapter 2 describes how to determine if a Field Replaceable Unit (FRU) in the T1900/
T1900C is causing the computer to malfunction. FRUs covered include the:
1. Upper and Lower System Boards
2. Floppy Disk Drive
3. Hard Disk Drive
4. Keyboard
5. Display
The Diagnostics Disk operations are described in Chapter 3 and detailed replacement
procedures are given in Chapter 4.
The following tools are necessary for implementing the troubleshooting procedures:
1. T1900/T1900C Diagnostics Disk
2. Phillips head screwdriver (2 mm)
3. Toshiba MS-DOS system disk(s)
4. 2DD or 2HD formatted work disk for floppy disk drive testing
5. Cleaning kit for floppy disk drive troubleshooting
6. PrinterportLED
7. RS-232-Cwraparoundconnector
8. Printerwraparoundconnector
9. Multimeter
10. External 5.25-inch floppy disk drive
11. ExternalCRT

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2.2 Troubleshooting Flowchart
Use the flowchart in Figure 2-1 as a guide for determining which troubleshooting procedures to
execute. Before going through the flowchart steps, verify the following:
❑Ask the user if a password is registered, and if it is, ask him or her to enter the
password. If the user has forgotten the password, connect the printer port wrap-
around board (F31PRT), then turn the POWER switch on. The computer will
override the password function by erasing the current password.
❑Verify with the customer that Toshiba MS-DOS is installed on the hard disk.
Non-Toshiba operating systems can cause the computer to malfunction.
❑Make sure all optional equipment is disconnected from the computer.
❑Make sure the floppy disk drive is empty.