Developing Handhelds - Slides 1pp

8/14/2019 Developing Handhelds - Slides 1pp

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AgendaLooking Ahead...

PGeneral Issues

PPlatform Overviews

PDevelopment ToolsPBusiness Summary


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General Issues

... a handheld is not a PC. Bigger is notnecessarily better. Speed is not

measured in megahertz or MIPS, oreven FLOPS for that matter. Developerswill need to shift paradigms whentargeting handhelds...


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General IssuesOpposite Usage Patterns

People generally usehandhelds in frequent, shortbursts; while people work on

PCs for several hours at atime.Accesses per day

Average sessiontime (minutes)Source: Palm, Inc user surveys

Waiting a few minutes for a PC to bootand a wordprocessor to load is acceptable

if ones going to write a paper for twohours.If the sole purpose of turning on thehandheld is just to look up somebodysphone number to call, waits can be

frustrating.


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General IssuesUser Interface

PSmall screen, most are 6cm * 7cm, some aresmaller.

PLimited resolution and color.

PSmall or no keyboard.

PStylus, not mouse programming will beslightly different.

PLess taps is better.


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General IssuesMemory Considerations

PMost handhelds do not carry secondarystorage all data are stored in the mainmemory.

POut-of-memory situations will occur moreoften applications must degrade gracefullyinstead of simply terminating.

PMemory grew from 2MB, 8MB, to 64MB. Butas handhelds grew smaller, dont expect thattrend to continue.


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General IssuesConserving Power

PAvoid lengthy computations leave theanalysis to the desktop machine.

P

Avoid polling, favor blocking. Thus the OScan suspend the CPU.

PLimit the use of peripheral devices sounds,serial, modems, etc.

POptimize for fast response time. Avoidbackground processing. PDAs only have oneuser to take care of.


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Platform OverviewsDiscussion Scope

P3Coms Palm OS.

PMicrosoft Windows CE.

PLineo Embedix Plus.


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Palm OSArchitecture Overview

Source: Palm OS website


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Palm OSPlatform Components

PPalm OS software.

PReference hardware design.

PHotSync conduit data synchronizationtechnology.

PPlatform component tools including an API

that enables developers to write applications.PSoftware interface capabilities to supporthardware add-ons .


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Palm OSApplication Startup and Stop

POnly one application at a time.

PNo exit command user simply selects anotherapplication.

PApplication launch codes:< sysAppLaunchCmdNormalLaunch Normal launch.< sysAppLaunchCmdCardLaunch Launch the application

from an expansion card.< sysAppLaunchCmdFind Finds a text string.< sysAppLaunchCmdInitDatabase Initialize database prior

to HotSync restore.

PApplication stop: appStopEvent upon receiving thisevent, an application must exit its event loop, close

any open files and forms, and exit.


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Palm OSMemory

P32-bit physical address space.

PAll memory are considered of a

part of a card.PCards may contain RAMs,ROMs, or a combination ofboth.

PPartitions:< Dynamic Heap< Storage Heap


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Palm OSMemory Manager

PGeneral memoryallocation/de-allocation.

PTwo types of memory:< Moveable chunks (handles).< Fixed chunks (pointers).

PHeap compaction< When allocation request failed.< Move unlocked moveable chunks down to lower

addresses.

PMemory chunks are marked with their owner

freed when the application terminates.


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Palm OSData Manager

PHigher-level data abstraction,for (more) persistent storage.

PDatabases instead of files.

PData divided into discretepieces that the system helpmanages.

PTwo major categories:< Record databases< Resource databases


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Palm OSData Manager

PRecord Databases< Most common for data storage.< Indexed records.< May be maintained in sorted order.< Each record belong to a category.< Backup may be done on a per-record basis.

P

Resource Databases< Free-form storage.< Linear search on access.


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Palm OSSpringboard Expansion

PUsed in Handspring Visorhandhelds.

P

Open standard documentation available fordownload, no user fees, noroyalties, no proprietary parts.

PLow cost uses the PCMCIA68-pin block.

P flexible power built-in supply

of 100mA at 3.3V.

Inserting a module into theSpringboard expansion slot


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Palm OSSpringboard Expansion

P Includes all necessarysoftware

P

Automatic softwareinstall/de-install no driverneeded.

PMicrophone support inhandheld. The Springboard expansion slot (below)and examples of possible Springboard

modules.


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Windows CEArchitecture Overview

Source: MSDN Library


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Windows CEPlatform Overview

PVersion 3.0 renamed to Pocket PC.PAvailable in three form factors:< Handheld PC touchscreen with keyboard, either

PCMCIA or CompactFlash.< Palm PC touchscreen without keyboard,

CompactFlash.< Auto PC in-car systems.

PUnicode-only character set.PSubset of the Win32 API.

PSupport for multithreaded applications.


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Windows CEDesign Goals

PSmall footprint.

PHigh modularity to build a high range of

embedded systems.PExecute-in-place (XIP) out of ROM.

PUse the Win32 API standard.

PPortable to different microprocessor familites.


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Windows CEMemory Management

P4GB virtual address space.

PData storage provided as a virtual disk in

RAM.PFamiliar Win32 and C memory-managementfunctions.

P

Record-based data access are also availablevia the Object Store.


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Windows CEDriver Architecture

PNative drivers no common interface model,loaded by parent processes.

PStream drivers exposed to applications

through the file system interface.PRegular IPC to drivers are supported.


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Windows CEDriver Architecture

Source: MSDN Library


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Lineo EmbedixArchitecture Overview on the Sharp SL-5xxx

Source: SL-5500 / System Architecture Overview


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Lineo EmbedixPlatform Overview

PMostly standard Linux system with kernelversion 2.4.

P

Busybox provides a subset of POSIXcommand-line utilities.

PQt/Embedded GUI, virtual framebuffer.

P

PersonalJava 1.2 environment included.PBase applications provided by Qt Palmtop.


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Development ToolsDiscussion Scope

PNative-code compilers.

PBytecode or source interpreters.

PJava environments (VM, libraries,and tools).


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Native Code CompilersCodeWarrior for Palm OS

P

The official development tool for the PalmOS.

PUses C, C++, or Motorola 68K assemblylanguage, program directly to the Palm OSAPI.

PHost platform: Windows or Mac.

P

C++ Support:


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Source: CodeWarrior 8 for Palm OS Platform Datasheet

Emulator

Debugger

ProjectManager

Editor

Wizards


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P IDE features:< GUI Builder.< Integrated debugging with emulator or on-

device trough serial/USB.< Source or assembly level debugging.< Code highlighting.< Wizards.< Class browser.

PRetail price: $499

P

Contact: http://www.metrowerks.com


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Native Code CompilersMicrosoft eMbedded Visual Tools

PMicrosofts CE development toolset.

PComponents:< eMbedded Visual C++.< eMbedded Visual Basic.< SDK and remote tools.

PFeatures the familiar Visual Studio user

interface.


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PProgram directly to the Windows CE API forC/C++.

PC++ offers the option of MFC and ATL for

Windows CE.PDebugging options:< Simulating Windows CE environment under

desktop Win32.< Remote debugging through cable.


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PCost: $14.95 (international shipping) freedownloads available.

P

Contact:http://msdn.microsoft.com/vstudio/device/prodinfo.asp


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Native Code CompilersMobileBuilder

PDevelop for several platforms from thesame code base.

PSupported targets: Palm OS, WindowsCE, Pocket PC, Windows NT, 98, 95, 3.1,MS-DOS, and DPMI.

P IDE with drag-and-drop RAD tools.

PHost platform: Windows 2000, NT 4.0,98, 95


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Visual

ProgrammingEnvironment

Powerful Form

Designer

Source: MobileBuilder Spec Sheet.


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PC-language, code to Penrights proprietaryAPI.

POver 350 handheld-focused API:

handwriting recognition, signature capture,bar code scanning, etc.

PSeparate runtime licenses for each target

platform.PPrice: $1595 per developer seat.

PContact: http://www.penright.com


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Bytecode InterpretersPocketC

PScripting, C-like language (but notC!).

PCross processor capability on Windows CE.

PAble to write code on handheld.

PDesktop IDE available; without GUI builder(Windows host).

PSeparate (incompatible) versions for Palm OSand Windows CE.


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Bytecode InterpretersPocketC

PPrice: $30 (Palm), $38 (Windows CE).

PContact: http://www.orbworks.com

Source: OrbWorks website


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Bytecode InterpretersNS Basic/Palm

PUses the BASIC programming language.

PDevelop on Windows desktop, with RAD tools.

P

Runtime size: 88K.PDebugging using Palm OS Emulator.

PPrice: $149.95

PContact: http://www.nsbasic.com/palm/


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Bytecode InterpretersNS Basic/Palm

Source: NS Basic website


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Bytecode InterpretersNS Basic/CE

PUses standard VBScript interpreter engine.

PCode directly in handheld.

P

IDE with RAD tools.PDatabase support - ADOCE.

PCross-processor support.


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Bytecode InterpretersNS Basic/CE

PRoyalty-free programdistributions.

PPrice: $149.95

PContact:http://www.nsbasic.com/ce/

Source: NS Basic website


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Java EnvironmentsKVM Reference Implementation

P

Focus on connected devices.PMultithreading support.

PVM size: 50K 80K, working memory:

128K.PCurrent target: Palm OS. Desktop:Windows and Solaris.

PNo native support.

PContact:

http://java.sun.com/products/cldc/ds/


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Java EnvironmentsJeode PDA Edition

PPersonalJava 1.2 compliant VM certified bySun.

PComplete JNI support.

PTargets: Windows CE, Linux (X11,Qt/Embedded, QPE).

PDynamic Adaptive Compilation (DAC).

PContact: http://www.insignia.com


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Java EnvironmentsWaba

PStrict subset of Java: language, class file,bytecode format.

PCross-platform VM: Palm OS, Windows CE,

Newton, TI, even DOS.PSmall footprint< VM+classlib less than 64K on Palm OS and

Windows CE.< Working memory less than 10K.


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Java EnvironmentsWaba

PVery limited set of libraries.

PNo multithreading, no exceptions.

PSupports serial and socket communications.

PNative interface implemented by modifyingVMs source code.

P

No-charge, GPL license.PContact: http://www.wabasoft.com


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Business SummaryTargeting Palm OS

PPros< Market share leader control the markets

directions.< OS built for small, low-powered devices may

appear in wider settings.< Vendor support and connectivity to enterprise

products: IBM, Oracle, Sybase, SAP.

PCons< High learning curve for developers.< Limited capacity of the Motorola Dragonball

processor.


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Business SummaryTargeting Windows CE

P

Pros< Similarity to other members of the Windows family simple transition from desktop-based Windowsdevelopment.

Developing Handhelds - Slides 1pp

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