fedex81 / javagear-mirror

JavaGear is a Sega Master System (SMS) and Game Gear (GG) Emulator for mobile phones and PCs.

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This is a github mirror for the Javagear 0.97 sourcecode. I've created this repository as a reference, I'm not intending to mantain/develop it.

Federico Berti 2019

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                                JavaGear          
                     Version 0.97 (6th July 2008)
                       http://www.javagear.co.uk     
                     
                  Copyright (c) 2002-2008 Chris White                                                

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1. Purpose & Cost
2. Introduction
3. Getting Started (Mobile Version)
4. Getting Started (Application & Applet Versions)
5. Usage (Mobile Version)
6. Lightgun Emulation
7. Saving Games
8. Known Limitations
9. Support & Acknowledgments

x. Appendices

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1. Purpose & Cost

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JavaGear is strictly a non-profit project. JavaGear is free. Its source code is free. Selling it is not allowed.

ROM images are copyrighted material. They cannot be distributed without the explicit permission of the copyright owner. No portions of the original game code are included in the package.

Please see the accompanying license for further details.

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2. Introduction

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JavaGear is a Sega Master System (SMS) and Game Gear (GG) Emulator for mobile phones and PCs.

JavaGear was originally coded as my final year university project. This is a highly optimised version of the original, with improved compatibility.

Four versions of JavaGear are provided:

1/ Application. Run JavaGear from your desktop, just like any native app.

2/ Applet Add JavaGear to your webpage.

3/ Mobile Accurate JavaGear for your mobile phone. Accurate and possibly a bit slow.

4/ Mobile Fast A faster version for mobile phones. Not as compatible.

The featuresets of these versions are outlined below:

                     Application | Applet | Mobile Accurate | Mobile Fast
                     .-----------+--------+-----------------+-----------.

High Compatibility | yes | yes | yes | no | SN76489 Sound Emulation | yes | yes | no | no | Lightgun Emulation | yes | yes | yes | no | State Saving | yes | no | yes | yes | SRAM Support | yes | no | yes | yes | NTSC/PAL Support | yes | yes | yes | yes | Redefinable Keys | yes | yes | yes | yes | Screen rotation | no | no | yes | yes | Screen scaling | yes | yes | yes | yes | '--------------------------------------------------'

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3. Getting Started (Mobile Version)

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Requirements:

• Fast MIDP2 phone
• Computer with Java installation (v1.1)
• A method of transferring JAR files to your phone
• Touchscreen phone (if you want to emulate the lightgun)
• Some games to try. Homebrew games and demos can be found at: http://smspower.org

There are two versions of JavaGear for mobiles included:

1/ Mobile (Fast Version) [JavaGearME_midp_fast_0.97.jar] Optimised version of JavaGear. Less compatible. Faster.

2/ Mobile (Accurate Version) [JavaGearME_midp_accurate_0.97.jar] Accurate version of JavaGear. More compatible. Slower.

Try the fast version first, and if the rom doesn't work use the accurate 
version. A list of titles that require the accurate version can be found 
in the appendix.

Adding a game to JavaGear:

• Copy the rom you want to package to the romtool directory. We'll call this 'game.sms' for this example. Note that some phones don't like filenames with special characters so you might want to consider renaming the rom first.

• Copy the version of javagear you want to use to the romtool directory. This will be a JAR file, and possibly a JAD file as well. We'll call this 'javagear.jad'.

• Open a command window (Windows: Start -> Run -> Type 'cmd')

• Check java is installed by typing 'java -version'. If it isn't, install it.

• Change to the romtool directory by typing something like: cd\JavaGear\romtool

• Type: java RomTool game.sms javagear.jad

• Your package will now be created!

Installing JavaGear on your phone

• You can upload the JAD/JAR to a server and download it through your phone WAP browser.

• Alternatively, you can try transferring the JAR file with bluetooth, infrared or data cable.

I can't provide you with specific help regarding this, as the process is different between phones and manufacturers.

You can also run the JAD/JAR with an appropriate phone emulator.

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4. Getting Started (Application & Applet Versions)

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Requirements:

• Computer with Java installation (v1.1)
• Some games to try. Homebrew games and demos can be found at: http://smspower.org

Application:

To run JavaGear as an application, just double click on the 'javagear.exe' file.

If you're not using Windows, try double clicking on the following file: JavaGear_j2se_accurate_0.97.jar

Alternatively you can run JavaGear from the command line: java -jar JavaGear_j2se_accurate_0.97.jar -rom game.sms

The '-rom' parameter is optional.

Applet:

1/ Edit JavaGear_j2se_accurate_0.97.html to specify a ROM. 2/ Double click on JavaGear_j2se_accurate_0.97.html

Note that with the applet version, you can either package the rom into the jar file with RomTool, or store it externally on the webserver. If you choose this method, just edit the 'rom' parameter in the html file.

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5. Usage (Mobile Version)

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The fastest emulation can be achieved with the following settings:

Scale : False Rotate : 0 Frameskip: 4 Throttle : False Min Sleep: 0

Game Gear games run faster than Master System games, as they use a smaller screen area.

Press the star key '*' to bring up the configuration menu. Use '2', '8' and '5' to navigate the menu.

The settings menu options are as follows:

• VIDEO MODE (NTSC / PAL) You can emulate an NTSC or PAL console. Most games run fine in NTSC. Some require PAL (Back to the Future 3, Operation Wolf)

• SCALE This is useful if you have a phone with a small display. If set to true, the screen will be scaled to fit the phone display.

  A side-effect is that this will slow down emulation and use more memory.

• ROTATE Rotate the screen in increments of 90 degrees. This is useful as the SMS has a landscape resolution, whereas most phones have portrait screens.

  As with scaling, this will slow down emulation and use more memory.

• FRAMESKIP Skip frames to increase emulation speed. A high value will speed up emulation, but make things more jerky.

• THROTTLE Locks emulation speed to 100% if JavaGear is running too fast. Most phones are still relatively slow, so you can probably leave this false. Alternatively lower the frameskip if emulation is too fast :)

• MIN SLEEP This is an important setting. JavaGear is a CPU intensive application. Some phones don't appreciate it working the CPU so hard and require a period of time where JavaGear sleeps per frame.

  If you find key-presses are sluggish / not registered, or there are other weird effects then experiment with this setting.

  Unfortunately setting a sleep time will slow down overall emulation.

• DEFINE KEYS Reconfigure control mappings. The controls in the menu cannot be changed.

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6. Lightgun Emulation

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Javagear emulates the lightgun. On a mobile phone you will need a touch-screen device and the accurate MIDP version.

You can enable the lightgun in the settings menu on the PC version. The lightgun is fired by clicking the mouse.

Here is a list of lightgun games:

Assault City Gangster Town Laser Ghost Marksman Shooting
Trap Shooting
Safari Hunt Missile Defense 3D [Requires 3D glasses so not much use] Operation Wolf [Set video mode to PAL] Rambo III Rescue Mission Shooting Gallery Space Gun Wanted

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7. Saving Games

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• Cartridge RAM

JavaGear emulates the extra RAM contained in some cartridges that is used to save game progress. (e.g. Phantasy Star).

To ensure your progress is saved, please exit JavaGear by choosing the EXIT option from the main menu. If you use your phone's red key to terminate JavaGear, progress may be lost.

• Save States

A better option is JavaGear's save state system. JavaGear can save your progress at any stage. Just select a slot from the main menu and choose save.

This could have problems on certain phones, as it depends on how much data your phone manufacturer lets you save. This varies between mobile handsets.

Saved games are not support on the applet version.

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8. Known Limitations

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• No TMS screen modes (F16 Flying Falcon)
• No Codemasters mapper (Micromachines etc.)
• No 3D Glasses (Missile Defence 3D, OutRun 3D etc.)

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9. Support & Acknowledgments

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I can't promise to answer every message on JavaGear, but every message will be read.

You can find my contact details on the javagear website: http://www.javagear.co.uk

Special thanks to:

• Charles MacDonald (SMS video documentation)
• Sean Young (Z80 documentation)
• Erik Duijs (Z80 CPU inspiration)
• Maxim (SN76489 Sound documentation)

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Appendix I - Titles that require the accurate version

The fast version of JavaGear doesn't emulate hardware sprite collisions.

The interrupt emulation is also less accurate, which can result in some in-game effects not functioning correctly.

Below is an incomplete list of games that require the accurate version. I welcome your compatibility reports.

• Cheese Cat'astrophe (SMS)
• Earthworm Jim (GG)
• Ecco the Dolphin (SMS, GG)
• Fantazy Zone Gear (GG)
• Impossible Mission (SMS)
• Taz-Mania (SMS, GG)

Lightgun games require the accurate version. Please see the Lightgun section for further details.

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Appendix II - RomTool

RomTool uses a database to identify ROMs.

The database is the same as the one used by Maxim's SMSChecker tool. The latest database files are available from here:

http://www.smspower.org/maxim/smschecker/

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