Dreampresent: The Dreamcast Presentation Tool

This is a presentation tool that runs on Sega Dreamcast. It was written in Ruby (instead of C/C++ which is usually the case for Sega Dreamcast programs!).

I developed this for RubyConf TW 2019 and ran my presentation on it. Later it was updated for RubyConf AU 2020 as you may see below.

Usage

You can use A or START to move forward, and use B to go back to the previous page.

Hold A + B + Start to quit.

The bottom of the screen shows the page progress and time progress (blue dreamcast swirl for page, red mruby for time).

The time is currently hardcoded to 35 minutes.

If you press Right on the D-pad, you move the time forward by 5 minutes, and back by 5 minutes if you press Left.

Building

Dreampresent uses KallistiOS (KOS) and mruby as dependencies. For building this program you have two options:

Using a working KallistiOS setup;
Use the provided Docker image below.

The presentation content can be found under romdisk/ directory, it's embedded when building the program.

Using your KallistiOS environment

If you have a working KallistiOS environment, you will have to install the rake and bison packages (e.g. using apt, brew or pacman). If you are using DreamSDK, you will have to install the RubyInstaller package separately, in that case, rake should be available in the PATH environment variable.

Install mruby:

cd /opt
git clone https://github.com/mruby/mruby.git
cd /opt/mruby
make MRUBY_CONFIG=dreamcast_shelf

These commands will produces all the necessary files for using mruby on Sega Dreamcast. After that, just navigate to the dreampresent directory then enter make. This will produces the dreampresent.elf file.

Note: You may consult this page for reference.

Using Docker image

To build, you need to pull the Docker image yujiyokoo/mruby-kos-dc.

docker pull yujiyokoo/mruby-kos-dc

Then you can build the binary with:

docker run -i -t -v $(pwd):/mnt yujiyokoo/mruby-kos-dc bash -c 'cd /mnt && . /opt/toolchains/dc/kos/environ.sh && make'

Executing

Lxdream

If you have the Lxdream Sega Dreamcast emulator installed, you can run it with:

lxdream dreampresent.elf

Making a bootable image

If you want to try this software in your real Dreamcast and/or in an emulator, you may create a Padus DiscJuggler (cdi) image. For example, if you are using DreamSDK, you may do the following:

make dist
elf2bin dreampresent.elf
scramble dreampresent.bin cd_root/1ST_READ.BIN
makedisc dreampresent.cdi cd_root

This will produces the dreampresent.cdi image file that you may burn onto a CD-R or use in a Dreamcast Emulator.

sizious / dreampresent