Midi Player Software for the Palm v1.0

Presented by MobileSoft Labs

Thank you for trying out our product.

Product Features of M.Play :

 Fully Graphical User Interface

 Supports Color or Grayscale Displays

 3-D Playback Controls

 Selectable Playlists

 Track and Timing Information

 Midi Capability

In this distribution, the following files are included :

 Readme.htm

 Mplay.htm

 Mplay.prc

 Midi library.pdb

 Classical.pdb

 MplayEditTrial.exe

 MplayEdit.htm

M.Play installs just like any other Palm OS applications :

Alternatively, you may receive M.Play by beaming from another handheld installed with the application.

When you start up the program, this is the main application screen that you shall see. On the top left-hand corner is the timer display, to inform how long the track has been playing. The top-right is the track information display, which shows some useful information on the sound track currently playing.

In the center is the application's control panel. The slider bar on the left tracks the sound track progress. The slider bar on the right is the volume control. Directly below the sliders are buttons to control the playback functions.

"Play", "Pause" and "Stop" buttons.

Control the playback of the current sound track.

"Skip Back" and "Skip Forward" buttons.

"Select" button.

This is the Select Sound Track Library screen where the user can manage the sound track libraries installed. Select a library and click "Ok" to load the playlist contained in that library.

A copy of the Trial version of M.PlayEdit Sound Track Library Creator has also been included. This Windows application allows you to convert your favorite midi sound tracks into the .pdb format acceptable by the Palm device.

Technical Discussion.

First of all, we intended M.Play to be a demonstration of our MLABS RAD rapid application development framework. RAD is a C++ framework for the PalmOS that enhances developer productivity by encouraging high code re-usability.

By using our Object Oriented Programming based approach we are able to complete the project in a short time without compromising quality and application file size. Generally, writing the application using RAD is easier and faster than normal C programming, and reduces the number of potential mistakes. Another benefit is that the application does not need a separate run-time engine or interpreter.

We managed to write M.Play using this approach in a fraction of the time required by the more traditional programming approaches.

Palm hardware currently does not have a speaker nor an amplifier circuitry built-in. Sound output is generated using PWM (pulse width modulation) by the Motorola processor onto a piezo. There are no filter circuits either. Thus there are no filtering of the higher harmonics (which can cause "hissing"). Probably the low speed of the processor also limit the frequencies that can be generated. Evidently all these restrict the audio range available. The TRG Pro does have a speaker, but there are other limitations as described below.

Only the midi format is supported native by the PalmOS at the moment, probably due to the small memory available on the device (as .wav or .mp3 formats requires much more memory capacity). Furthermore, only Format 0 of the midi file format is supported, i.e. no simultaneous tracks of multiple instruments. We speculate this is probably done to put everything into a single block of memory.

Meanwhile, we are open to suggestions as to any other features you like to see implemented, or what other demonstration applications next. Please let us know if you have any good ideas.

All questions can be directed to :

We shall try to be as responsive as we can to your questions and comments, but we ask your forgiveness if we are ever late in replying, probably due to our other work-related commitments.