Texas Instruments Personal Learning Tool PLT SHH1

Date of introduction:  never Display technology:  LCD dot matrix
New price:    Display size:  320 * 240 pixels
Size:  7.1" x 3.3" x 0.90"
 181 x 85 x 23 mm³
Weight:  9.7 ounces, 274 grams Serial No:  
Batteries:  Li-Ion 3.7V 1400mAh Date of manufacture:  year 2002
AC-Adapter:  AD2973 Origin of manufacture:  Taiwan (I)
Precision:   Integrated circuits:  CPU: TI-OMAP1509E
 SDRAM: Hynix HY57V281620A
 Flash: Toshiba TC58V64A, Fujitsu 29LV400TC
Program steps:  16M Bytes SDRAM, 512k Bytes NOR Flash-ROM, 8M Bytes NAND Flash-ROM Courtesy of:  Joerg Woerner

We received this unique graphing calculator with the help of a wonderful friend in January 2007. It was one of two prototypes offered on eBay but never intended for sale. We assume that only about 50 prototypes of the PLT SHH1 were used for field tests.

The backside of the calculator teases us with some valuable information as a start point of further research: Model No: PLT - SHH1, © 2002, Made in Taiwan, CPU: POMAP1509E. 

In the meantime we learned that Texas Instruments developed a family of next-generation Personal Learning Tool products based on the LINUX operating system. The Dallas, TX based team nicknamed it PET Project and this PLT SHH1 is actually a first generation PET device nicknamed Spot Hand Held. A larger, landscape oriented PET device was labeled PLT FHH1 for Fido Hand Held. The second generation PET device PLT SU1 was known as Toto Hand Held.

The PLT SHH1 seems to be a merger of a PDA (Personal Digital Assistant) and a graphing calculator. Both the size and resolution of the LCD screen are known from PDA's of that epoch and even a Stylus is used to operate the calculator.

Don't miss the Avigo 10 developed already 5 years earlier!

The Li-ion battery of the PLT SHH1 states three different products to be powered with:

• PLT SHH1: Spot Hand Held
PLT FHH1: Fido Hand Held
PLT WS1:  Wireless Sled - A cradle with wireless LAN support

With the PLT DS1 Data Sled a smaller cradle supporting just a USB connection was developed, too.

Architecture: Dismantling the PLT SHH1 reveals a modern architecture based on the OMAP architecture introduced by Texas Instruments already in 2001. The different memory chips used in this Engineering Samples promised an unbelievable huge workspace of 24M Bytes and even an additional slot for a SD Memory Card. In addition we recognized an unknown Philips CA4885 device.

Processor: The first generation OMAP™ 1510 combines in one system the TMS320C55x DSP (Digital Signal Processor) with an ARM925 RISC (Reduced Instruction Set Computing) to provide the perfect balance between performance and power consumption for mobile products. It was used between 2002 and 2006 in products like the Palm Tungsten T, Hewlett Packard iPAQ H6340, and Nokia 9300/9500 Communicator.

Memory: The PLT SHH1 makes use of three different memory chips:

• NOR Flash-ROM

Flash memory is non-volatile and does not need a battery to maintain the information stored in the chip. In the past years two different technologies emerged in parallel with some advantages and disadvantages.

The NOR Flash-ROM was invented by Toshiba in 1984 and found its way immediately as a replacement of the more expensive ROM (NRE mask costs) and EEPROM (device costs) memory. NOR Flash-ROMs use an address and data bus to allow the random access to any memory location. Main disadvantages of NOR Flash-ROMs compared to NAND Flash-ROMs are the higher costs, larger housings and slower write speeds.

The disassembled PLT SHH1 (Manufactured 2002) makes use of one 29LV400TC, manufactured by Fujitsu, Japan with a 256k*16 organization. Please keep in mind that even the TI-89 Titanium used 2M*16 Flash-ROM.

The NAND Flash-ROM architecture was introduced by Toshiba in 1989 and is based on pages of typically 512 to 2048 Bytes and blocks of typical 32 or 64 pages.

While programming is performed on a page basis, erasure can only be performed on a block basis. NAND Flash-ROMs requires bad block management to be performed by device driver software or hardware. Due to the missing address bus the NAND Flash-ROM chip doesn't allow random access to the individual memory positions and therefore it can't be used for program memory of a microprocessor. Typical use of NAND Flash-ROM memory is file based mass-memory storage such as memory cards.

The disassembled PLT SHH1 makes use of one Toshiba TC58V64A NAND EEPROM with 8M Bytes size compared with 32M Bytes CMOS NAND Flash-ROM located in the later TI-Nspire.

SDRAM is the abbreviation of synchronous dynamic random access memory and is used as program and data memory for microprocessor systems. Each bit of data in a SDRAM is stored in separate capacitor on the integrated circuit. Since these capacitors leak charge, the information eventually fades unless the capacitor charge is refreshed periodically.

Because of this refresh requirement, it is a dynamic memory as opposed to SRAM and other static memory. Its advantage over SRAM is its structural simplicity: only one transistor and a capacitor are required per bit, compared to six transistors in SRAM. This allows SDRAM to reach very high density at low cost. Since SDRAM loses its data when the power supply is removed, it is accompanied usually by a NOR Flash-ROM.

During power-up of the system the program content of the NOR Flash-ROM is simply copied into the SDRAM and executed from there. We assume that the PLT SHH1 uses the SDRAM as workspace for user data but stores changes on them into the NAND Flash-ROM.

The disassembled PLT SHH1 makes use of one Hynix HY57V281620A SDRAM with 8M*16 bits size compared with 16M*16 bits SDRAM located in the later TI-Nspire. We recently discovered a second PLT SHH1 using a Winbond W9812GBH75L SDRAM with 8M*16 bits size, too.

Display: The PLT SHH1 uses a high-contrast display with a resolution of 240 * 320 pixels, a huge improvement over the TI-89 Titanium with 100 * 160 pixels or the Voyage 200 with 128 * 240 pixels. The large touch-screen display includes a novel split screen capability with up to 4 views.

Two components not easily detected on the printed circuit board (PCB) of the display module are the driver circuits of the LC-Display. They are just bare chips mounted on a flexible piece of circuit board attached between the display and the main PCB.

Connectivity: The PLT SHH1 features a total of five connectors to the outside world:

• Serial port similar to TI-83
Charger for PLT SHH1 battery
• Connector for Charging cradle

Lower BUS connector to the PLT WS1 Wireless Sled and PLT DS1 Data Sled
Upper BUS connector, e.g. for USB module PLT USB1

The serial port of the calculator allows the connection to the Calculator-Based Laboratory system CBL 2 and the Calculator-Based Ranger CBR and probably an external keyboard. 



WED Aug 21
2002 Built by inferno  

The software used for this early PLT SHH1 was defined as beta release and a file called ReadMeText added some valuable informations about the hardware and software.

You can check the ROM version of your PLT SHH1 using the following key sequence and reading the text on your screen:

[HOME] [BuildInfo]

Texas Instruments worked secretly on the Phoenix 1 and announced in 2006 the TI-Nspire CAS+, but it took another year before the long-awaited TI-Nspire calculator family arrived finally July 2007 in the store shelves. The PET program provided Texas Instruments obviously with a lot of valuable lessons and insights that found its way into the TI-Nspire, e.g.:

• Split-screen options
• Dynamic linking between multiple representations for interactive feedback
Computer like cursor supporting “Grab-and-Move”


Find here the ReadMeText:

Welcome to your PET!

This document is intended to give an overview of what this beta release of the PET software and hardware can and cannot do.

This device is commonly known as SPOT and is one of two versions of PET. The other, with a screen oriented horizontally that is twice as large as SPOT's and minus the majority of the buttons, is known as FIDO.

What Works

This device has been modified to enable certain operations within the graphing calculator.
The Graphing Calculator is very close to being functionally complete. This version contains a well formed CAS. However, the final product will use the more teacher friendly Exact Arithmetic.
Scribe is the word processing program. It can incorporate objects such as Math boxes (a TI-Interactive concept), graphs, and inthe future, spreadsheets. Examples of its multifaceted functionality can be found in the contend/scribe folder.
Datasheet is a program that can run on its own or be incorporated into either the graphing calculator or Scribe. It currently has no actual connection to the math server that runs on the calculator, and as such is limited in terms of functionality. You can't put formulae in cells - only numbers and text strings are currently alloweed. It is under development and should be considered as such.
Contrast is a utility that allows you to adjust the contrast on the screen by using a slider bar.
Imagenotes is a program that is not expected to be delivered in version 1.0 of PET. It allows users to view and create hotspots on pictures that open annotations for that particular spot. This functionality is intended to be incorporated into Sketch.
Sketch is a program that can create and draw on existing images.There are known issues with this program. The format used for pictures is a grayscale format given the extension of .bit. Conversions tools are available to turn .gif files into .bit files.
Other functions that are planned for this release are most notably a student planner, plus the wireless connectivity. There is no current ability to browse the web with these devices. We hope that these devices will be at the very least a promise of the future of TI educational handhelds. If you have any questions on them or their use, contact Jim Watkins, Jim Arnold, or George Thixton.

Prepared by Kevin Jones on July 31, 2002.

This device, the software, and all other files are considered at this point TI-Confidential. 


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If you have additions to the above article please email:

© Joerg Woerner, February 4, 2007. No reprints without written permission.