Sharp Zaurus
The Sharp Zaurus is a series of personal digital assistants (PDAs) developed and manufactured by Sharp Corporation, a Japanese electronics company, spanning from 1993 to the mid-2000s, renowned for introducing innovative handheld computing features such as color LCD screens, integrated cameras, handwriting recognition, and eventually Linux-based operating systems that appealed to developers and enthusiasts.[1][2][3] The Zaurus line originated as a successor to Sharp's earlier Wizard organizers, with the first model, the PI-3000, launched in Japan in September 1993, featuring a monochrome LCD screen, handwriting recognition, and optical communication for data transfer.[1] In 1995, the Zaurus K-PDA was released in the United States, marking Sharp's entry into the international market with a built-in QWERTY keyboard for easier text input, alongside standard PDA functions like calendar, contacts, and scheduling.[1][3] By 1996, Sharp advanced the series with the MI-10 and MI-10DC models, the world's first color PDAs equipped with a 5-inch color TFT LCD, built-in camera for photo capture, audio recording, and Internet connectivity, priced at 120,000 yen and 155,000 yen respectively.[2] The series evolved significantly in the early 2000s with the introduction of the SL lineup, which shifted to an embedded Linux operating system, positioning the Zaurus as one of the first mainstream PDAs to leverage open-source software for enhanced customization and performance.[4][3] The SL-5000D developer edition debuted in November 2001, powered by a 206 MHz Intel StrongARM SA-1110 processor, 32 MB SDRAM, 16 MB flash ROM, a 240x320 resolution color touchscreen, sliding QWERTY keyboard, and support for CompactFlash and SD cards, running Linux 2.4.6 with the Qt/Embedded interface and Java compatibility, followed by the consumer SL-5500 (codenamed Collie) with 64 MB SDRAM.[4][3] Later models like the SL-5600 (2003) upgraded to a 400 MHz Intel XScale processor for improved speed and efficiency, while the SL-C1000 (2003) featured a 416 MHz CPU, 128 MB flash ROM, 640x480 VGA touchscreen, and USB host/client capabilities, fostering a dedicated community for software development despite limited commercial success in the West.[3][5] The Zaurus series ultimately contributed to the evolution of mobile computing by bridging proprietary PDA designs with open platforms, though Sharp discontinued the line amid shifting market dynamics toward smartphones.[3]History and Development
Origins and Early Japanese Models
Sharp introduced the precursor PA series of personal digital assistants (PDAs) in 1985 with the PA-100, marking one of the earliest efforts in Japan to develop portable electronic organizers for personal information management.[6] This model focused on basic functions such as scheduling and calculations, laying the groundwork for Sharp's expansion into mobile computing devices amid the growing demand for compact productivity tools in the domestic market.[7] Building on this foundation, the PA-7000, released in January 1987, became a landmark device as the world's first kanji-capable electronic organizer, enabling users to input and display Japanese characters alongside standard calendar, memo, phone book, and calculator features.[8] It achieved rapid commercial success, selling 500,000 units within its first year, and introduced expandable functionality through optional IC cards for dictionaries and other applications, solidifying Sharp's early leadership in Japan's PDA sector.[6] Innovations in input methods followed, with stylus-based handwriting recognition emerging in Sharp's product lineup by 1989 through EL display technology that simultaneously detected pen coordinates and displayed text, enhancing usability for Japanese character entry.[8] In July 1992, Sharp launched the PV-F1 as a prototype electronic organizer, incorporating advanced features like handwritten input via stylus, schedule management, and IC-card compatibility for data storage and expansion.[6] This model also served as a compact English-to-Japanese translation system, the smallest and lightest of its kind at the time, though its bulky design and high price limited initial adoption.[6] The PI series debuted in October 1993 with the PI-3000 (also known as the LCD Pencom Zaurus), transitioning the line toward more sophisticated PDAs equipped with touchscreen interfaces supporting stylus input and handwritten character recognition tailored for Japanese users.[6] Subsequent models, including the PI-6500, PI-7000, and PI-8000, built on this platform, running Sharp's proprietary Synergy operating system and featuring processors like the ESR-L (SC62015) with a Z80 co-processor for efficient handwriting processing and compatibility with legacy IC cards.[9] These devices emphasized portability at around 250 grams, infrared PC connectivity, and integrated business tools, driving strong market performance. By 1995, cumulative sales of Zaurus PDAs in Japan exceeded 1 million units, establishing Sharp's dominance in the domestic market through these foundational innovations in stylus-driven input and character recognition systems.[10]International Launch and Challenges
Sharp's initial international efforts with the Zaurus line began in the early 1990s through a partnership with Apple, resulting in the Expert Pad series as licensed clones of the Newton MessagePad. The Expert Pad PI-7000, announced on August 3, 1993, at Macworld Expo Boston, featured an ARM 610 processor and ran a version of Newton OS 1.0, supporting handwriting recognition and basic productivity tools in a compact form factor aimed at global markets including the US. Priced at $899 USD, the PI-7000 and its successor PI-7100 (updated to support Newton OS up to 1.3) were positioned as affordable alternatives to Apple's device but struggled with the same recognition inaccuracies and high cost that plagued the Newton ecosystem, leading to limited adoption and Sharp's quick withdrawal from this segment by 1994.[11] Building on this experience, Sharp developed the ZR series specifically for export markets between 1996 and 1998, designing these models without release in Japan to target international competition in the burgeoning PDA space. The lineup included the ZR-3000 and ZR-3500 (both with 1 MB RAM and 320x240 touch screens), ZR-5000 (a clamshell variant), and ZR-5700 and ZR-5800 (with expanded memory and features like a built-in spreadsheet). Powered by the ESR-L (SC62015) processor alongside a Z80 co-processor, these devices ran Sharp's proprietary Synergy OS and incorporated a hybrid keyboard-stylus input system for enhanced productivity, while the ZR-5800 added a backlit 320x240 display for better visibility.[9][12] Despite these innovations, the ZR series faced significant hurdles in the US and Europe due to pricing in the $400–600 USD range, which positioned it as a premium option against more affordable rivals like the PalmPilot. Launched amid the rise of simpler, lower-cost PDAs, the devices suffered from poor timing, insufficient third-party software support—stemming from Sharp's closed development policies—and lack of aggressive marketing, resulting in dismal sales and retirement of the line after just two years. Limited distribution further hampered availability, with sporadic presence in European markets and no substantial foothold in the US, ultimately prompting Sharp to refocus on domestic innovations like the MI and MT series post-1998.[9][13]Shift to Open-Source and Later Evolution
In the late 1990s, Sharp introduced the MI series of Zaurus devices exclusively in the Japanese market, spanning from 1996 to 2001, which featured advanced models such as the MI-10 and MI-10DC—the first to incorporate a reflective color TFT display for improved visibility and power efficiency.[2] Other notable MI models included the MI-110M, MI-106, MI-106M, and MI-310, all powered by Hitachi SH3 processors operating at speeds ranging from 30 to 120 MHz, and running the proprietary Zaurus OS for personal information management and basic connectivity.[6] These devices emphasized portability and integration with emerging mobile technologies, building on earlier Zaurus successes to appeal to business users in Japan. Complementing the MI series, Sharp launched the MT series during the same period (1998-2001), marketed as "Browser Boards" or "Communication Pals" for enhanced mobile integration, particularly email and web browsing on the go.[14] Key models included the MT-200, MT-200SA, MT-300, and MT-300C, which utilized similar Hitachi SH3 processors (30-120 MHz) and Zaurus OS, but added dedicated keyboards and compact designs targeted at younger users and professionals needing seamless communication tools.[6] The MT-300, for instance, focused on compactness and email functionality, reflecting Sharp's strategy to diversify Zaurus offerings for niche mobile scenarios. By 2001, Sharp pivoted to open-source software for the SL series, adopting Linux as the operating system to leverage growing developer communities and enable more powerful, customizable applications on modern ARM-based processors like Intel's StrongARM.[15] This shift was driven by the limitations of the proprietary Zaurus OS in supporting advanced features and third-party software—Linux allowed access to a wide range of applications from the open-source ecosystem, breaking from traditional Hitachi SH3 designs to attract global developers and enhance competitiveness.[16] International expansion faltered around 2003, with Sharp discontinuing Zaurus sales in Europe after the underperformance of the SL-5500G model, leading to a strategic refocus on the Japanese domestic market.[17] This retreat was exacerbated by intensifying competition from emerging smartphones, which offered integrated voice, data, and multimedia capabilities that overshadowed dedicated PDAs. By the early 2000s, Sharp had achieved over 1 million cumulative Zaurus units sold, primarily in Japan, underscoring the line's domestic success despite global challenges.[6]Hardware Design
Processors, Memory, and Storage
The early Sharp Zaurus models featured basic processing capabilities suited to their role as electronic organizers. The PA series utilized the Sharp ESR-H (SC61860) processor, accompanied by 32 KB of SRAM (expandable to 160 KB) and 256 KB of ROM.[18] Subsequent PI and ZR series models from the mid-1990s employed the Sharp ESR-L (SC62015) 8-bit processor with a Z80-compatible co-processor for tasks like handwriting recognition, offering limited memory such as 288 KB in the PI-3000 and 2 MB in the ZR-5800, which provided approximately 1.6 MB of user-available space.[19][12][9] These devices relied on IC cards for data storage and expansion, allowing modular upgrades without internal modifications.[9] Transitioning to the MI and MT series in the late 1990s, Sharp incorporated the Hitachi SH3 RISC processor, operating at clock speeds ranging from 30 MHz to 120 MHz, which supported enhanced multitasking and connectivity features.[9] Memory configurations remained modest, typically 2-4 MB of RAM, reflecting the era's focus on efficiency over capacity. The ZR series introduced PCMCIA Type II slots for expansion, enabling compatibility with PC cards for additional storage and peripherals like modems.[20] The SL series represented a major advancement in computational power, beginning with the StrongARM SA-1110 processor at 206 MHz in models such as the SL-5000 and SL-5500, which included 64 MB of RAM for running more demanding applications.[21] Later iterations, like the SL-C1000, upgraded to Intel XScale PXA-series processors (e.g., PXA-270 at 416 MHz), paired with 64 MB of RAM and 128 MB of internal flash memory for persistent storage.[22] Expansion shifted to CompactFlash (CF) Type I/II and Secure Digital (SD) slots, providing flexible options for microdrives and high-capacity cards to extend storage beyond onboard limits.[23]| Series | Representative Processor | RAM Examples | Storage/Expansion |
|---|---|---|---|
| PA | Sharp ESR-H (SC61860) | 32 KB (expandable to 160 KB) | IC cards |
| PI/ZR | Sharp ESR-L (SC62015) + Z80 co-processor | 288 KB (PI-3000); 2 MB (ZR-5800) | IC cards; PCMCIA Type II (ZR) |
| MI/MT | Hitachi SH3 (30-120 MHz) | 2-4 MB | PCMCIA |
| SL | StrongARM SA-1110 (206 MHz); Intel XScale PXA (up to 416 MHz) | 64 MB (SL-5500, SL-C1000) | 128 MB flash (SL-C1000); CF/SD slots |
Displays, Input, and Form Factors
The Sharp Zaurus series began with monochrome touchscreen displays in the PI series, typically featuring resolutions such as 239×168 pixels to support compact personal organization tasks, while the ZR series used 320×240 pixels.[24][12] These screens were designed for low power consumption and readability in various lighting conditions, prioritizing portability over visual richness. The ZR-5800 introduced backlighting to this monochrome setup, enhancing usability in dim environments while maintaining the 320×240 resolution.[12] A significant advancement occurred with the MI series in 1996, where the MI-10 debuted the world's first reflective color thin-film transistor (TFT) LCD, a five-inch display that relied on ambient light for visibility without backlighting, thus extending battery life.[25] This reflective technology marked a shift toward color for better data visualization, though it remained sensitive to direct sunlight. Later SL series models, such as the SL-C1000, elevated display quality with backlit color TFT screens reaching 640×480 VGA resolution, providing sharper images suitable for multimedia and productivity applications.[5] The MI-EX1 prototype further pushed boundaries with an experimental 640×480 VGA color display, foreshadowing higher-resolution trends in mobile devices.[9] Input methods across the Zaurus lineup emphasized intuitive interaction, starting with stylus-based handwriting recognition (HWR) introduced in the PA and PI series for natural text entry in Japanese and English.[9] This feature used a dedicated co-processor to interpret strokes in real-time, enabling users to write directly on the touchscreen without a physical keyboard. The ZR and SL series expanded options with integrated QWERTY keyboards; the SL-5500 featured a mechanical slide-out design with 37 keys for tactile typing, balancing compactness with efficiency.[26] Certain MT series variants omitted touchscreens entirely, relying on keyboard input to function as dedicated accessories.[9] Form factors evolved to suit diverse use cases, with the PI and MI series adopting slim slab or clamshell designs that were pocketable and weighed under 200 grams, ideal for on-the-go personal information management.[9] The ZR series shifted to a keyboard-integrated clamshell resembling a miniaturized laptop, increasing size for better productivity but limiting portability compared to earlier slabs. Similarly, SL models like the SL-C1000 combined a rotatable touchscreen with a full QWERTY keyboard in a compact, DS Lite-sized body, measuring about 130x90x20 mm. The MT series diverged as flat "browser board" accessories attachable to mobile phones, forgoing standalone portability in favor of integration with cellular devices. Unique expandability in SL models via CF and SD slots allowed community modifications, such as external display connections for enhanced output.[5][9]Models by Series
PI and ZR Series
The PI series represented Sharp's initial foray into personal digital assistants (PDAs) targeted at the Japanese domestic market, establishing the Zaurus brand as a pioneer in compact, stylus-based information management tools. Launched in 1993, these models emphasized portability and integration of business functions such as scheduling, address books, and note-taking, with a focus on handwritten input for ease of use among professionals. The series became domestic bestsellers, capturing significant market share in Japan during the 1990s due to their affordability and innovative design.[27][28] The inaugural model, PI-3000, debuted in October 1993 as a basic organizer priced at 65,000 yen, weighing 250 grams to fit easily in a suit pocket, and featuring an LCD display with stylus-based handwritten input and infrared data exchange capabilities for PC synchronization. It included a built-in English-to-Japanese translation system, making it particularly appealing for business users, and achieved over 1 million units sold by October 1996. Subsequent PI models from 1996 to 1998, including the PI-6500, PI-7000, and PI-8000, built on this foundation by enhancing handwriting recognition accuracy and adding advanced connectivity options like fax transmission, PC linking, and early Internet access, while maintaining the series' emphasis on personal information management (PIM) with 1-2 MB of memory and PCMCIA expansion slots for peripherals. These evolutions solidified the PI series' role in creating demand for mobile productivity tools in Japan.[27][28]| Model | Key Features and Specs | Release Context |
|---|---|---|
| PI-3000 | Handwritten input, infrared PC sync, LCD display, 250g weight | Basic organizer; bestseller with 1M+ units by 1996 |
| PI-6500/7000/8000 | Improved recognition, fax/Internet add-ons, 1-2 MB RAM, PCMCIA slots | Enhanced PIM tools; evolved for broader business use |
| Model | Key Features and Specs | Release Context |
|---|---|---|
| ZR-3000/3500 | Entry-level PIM, basic display, optional 14.4 kbps modem | 1996 affordable exports |
| ZR-5000/5700 | Improved battery, fax/VT-100 emulation, 1-2 MB RAM, PCMCIA | 1995-1997; U.S. focus |
| ZR-5800 | Backlit 320x240 LCD, 2 MB RAM, keyboard/stylus, ~30 hr battery | 1998; enhanced visibility and connectivity |
MI and MT Series
The MI and MT series marked Sharp's advancement in color PDA technology and mobile connectivity during the late 1990s, primarily for the Japanese market, building on earlier monochrome models with enhanced displays and integration capabilities. These series utilized the proprietary Zaurus OS and Hitachi SH3 RISC processors, ranging from 30 MHz in initial models to 120 MHz in later ones, with memory configurations of 2–10 MB RAM across the lineup. Focused on personal productivity and emerging internet access, the MI models emphasized compact, standalone devices with innovative reflective color screens, while the MT models prioritized accessory-like designs for phone attachments and web browsing. The MI series debuted in 1996 with the MI-10 and MI-10DC, the first Zaurus devices to feature a color display—a 5-inch reflective TFT LCD with 320×240 resolution and 16-bit color depth—enabling Internet connectivity, e-mail, fax transmission, and optional digital camera integration for photo capture. Powered by a 30 MHz Hitachi SH3 processor and 2 MB RAM, these models included handwriting recognition and a built-in address book, priced at 120,000 yen for the base MI-10 and 155,000 yen for the DC variant with camera support. Priced at 120,000 yen, the MI-10 measured approximately 170 × 95 × 25 mm (without lid) and supported IrDA and PC card interfaces for expandability.[2][30] Follow-up MI models in 1997–1999, such as the MI-110M, MI-106, and MI-106M, refined the design with higher memory capacities up to 10 MB and improved battery life of around 40 hours on two AAA batteries, while maintaining the 320×240 color TFT display for better readability in various lighting. The MI-110M, for instance, highlighted Sharp's push toward more capable pocket computing at 83,000 yen, with developer-friendly ports like option ports and IrDA for custom accessories. By 1998, the MI-310 introduced a more portable form factor—a 3.8-inch 16-bit color TFT at 320×240 resolution, 66 MHz SH3 processor, 10 MB RAM, 146.5 × 83.5 × 18 mm dimensions, and 240 g weight—enhancing speed and compactness for on-the-go use. The MI-EX1 prototype (2000–2001) pushed boundaries further with an XVGA (640×480) color display and up to 120 MHz SH3 clock speed, serving as a testbed for higher-resolution interfaces under Zaurus OS.[30][31][9]| Model | Release Year | Processor & Speed | RAM | Display | Key Features | Price (¥) |
|---|---|---|---|---|---|---|
| MI-10/10DC | 1996 | SH3, 30 MHz | 2 MB | 5" reflective TFT, 320×240, 16-bit | Internet, camera option, handwriting | 120,000–155,000 |
| MI-110M/106/106M | 1997–1999 | SH3, ~30–66 MHz | 10 MB | 320×240 color TFT | Extended battery, IrDA/PC card ports | ~83,000 |
| MI-310 | 1998 | SH3, 66 MHz | 10 MB | 3.8" TFT, 320×240, 16-bit | Compact design, 240 g weight | 110,000 |
| MI-EX1 | 2000–2001 | SH3, up to 120 MHz | N/A | XVGA, 640×480 color | Prototype high-res display | N/A |
SL Series
The SL series represented Sharp's transition to Linux-powered personal digital assistants (PDAs), beginning with international models in 2001 that emphasized open-source software and enhanced productivity features. These devices featured mechanical QWERTY keyboards, color displays, and expandable storage via CompactFlash (CF) and Secure Digital (SD) slots, targeting users needing robust computing in a portable form factor. Storage capacities ranged from 32MB to 128MB internally, with expansion options allowing for additional memory and peripherals to support tasks like document editing and data synchronization.[32] The initial international lineup included the SL-5000D, a developer-oriented variant released in 2001 with 32MB of memory for software testing and prototyping.[33] This was followed by the SL-5500 (codenamed Collie) in 2001, equipped with a 206MHz Intel StrongARM processor, 64MB RAM, and a 3.5-inch 240x320 color TFT reflective touchscreen.[32] The SL-5500G added GSM connectivity for mobile data, while the SL-5600, launched in 2003, upgraded to a 400MHz Intel XScale processor and 96MB total memory (32MB active SDRAM and 64MB flash ROM), improving performance for multitasking.[34] All models in this subseries ran a customized Linux distribution, supporting Java applications and emphasizing connectivity through CF Type II and SD/MMC slots for peripherals like modems and storage cards.[35] In Japan and select international markets, Sharp expanded the SL series with entry-level and advanced models from 2002 onward. The SL-A300 (codenamed Discovery), introduced in 2002, served as an accessible option with a 200MHz Intel XScale PXA210 processor and 64MB SDRAM, focusing on lightweight productivity in a lightweight slab design without a built-in keyboard.[36] The SL-B500, also from 2002, targeted budget users with similar entry-level specs, including expandable storage and basic Linux functionality for scheduling and note-taking. Higher-end variants like the SL-C700 (2003) featured a 400MHz Intel XScale PXA250 processor, 64MB flash memory, 32MB SDRAM, and a 3.7-inch 640x480 VGA 16-bit color touchscreen, enabling sharper visuals for document viewing.[37][38] Subsequent models built on this foundation, with the SL-C750 (2003) offering 64MB flash and 64MB SDRAM alongside the same 400MHz PXA255 processor and VGA display for improved multitasking.[39] The SL-C760 (2003) enhanced capacity to 128MB flash (approximately 65MB user-available) and 64MB SDRAM, supporting more extensive application storage while maintaining the clamshell form with slide-out keyboard.[40] The SL-C860 (2004) further refined these specs with 64 MB SDRAM and 128 MB flash memory with the 400MHz processor, prioritizing high-resolution output and slot-based expansion.[41] The SL-6000 subseries (2003-2005), including variants like the SL-6000N, SL-6000W, SL-6000L, and SL-C1000, adopted a 400MHz Intel XScale PXA255 processor, 64MB flash and 64MB SDRAM, and a 4-inch 640x480 color touchscreen running Linux Embedix.[42] These models emphasized productivity with CF Type II and SD slots for expansion, plus built-in microphone and speaker for voice applications. The SL-C1000 stood out as the high-end option, incorporating 10/100 Ethernet for wired networking alongside its 128MB flash storage, catering to users requiring desktop-like connectivity.[5] International sales of the SL series concluded after 2003 amid declining PDA market demand, with Sharp ceasing U.S. distribution by 2004 due to an 18% global sales drop for non-phone PDAs that year.[43] Community-driven software developments, such as custom Linux distributions, extended the usability of SL models for enthusiasts post-support.[37]| Model | Release Year | Processor | RAM/Storage | Display | Key Features |
|---|---|---|---|---|---|
| SL-5000D | 2001 | StrongARM 206MHz | 32MB RAM | 240x320 color | Developer edition, CF/SD slots |
| SL-5500 | 2001 | StrongARM 206MHz | 64MB RAM / 16MB ROM | 3.5" 240x320 color TFT | Mechanical keyboard, Linux OS |
| SL-5600 | 2003 | XScale 400MHz | 32MB RAM / 64MB flash | 240x320 color | Upgraded performance, expansion slots |
| SL-A300 | 2002 | XScale PXA210 200MHz | 64MB SDRAM | Color TFT | Entry-level slab without keyboard, lightweight |
| SL-C700 | 2003 | XScale PXA250 400MHz | 32MB SDRAM / 64MB flash | 3.7" 640x480 VGA | High-res display, productivity focus |
| SL-C760 | 2003 | XScale PXA255 400MHz | 64MB SDRAM / 128MB flash | 3.7" 640x480 VGA | Enhanced memory, slide-out keyboard |
| SL-6000 | 2003 | XScale PXA255 400MHz | 64MB SDRAM / 64MB flash | 4" 640x480 color | Embedix Linux, CF/SD expansion |
| SL-C1000 | 2005 | XScale PXA270 416MHz | 64MB SDRAM / 128MB flash | 4" 640x480 color | 10/100 Ethernet, wired connectivity |