Debian/Ubuntu Installer

We are currently working on an Ubuntu package for Scratch 1.4.  Below you will find information about the experimental Ubuntu package for Scratch 1.3.1. 

The following package is still experimental and you should treat it as such.  See known issues below for details about bugs and things we need help with.

Download latest version of Scratch for Linux, scratch-1.3.1_0.9-4_i386.deb for Ubuntu 8.10.

sudo dpkg -i scratch-1.3.1_0.9-4_i386.deb

sudo dpkg --remove scratch-1.3.1

sudo apt-get install alsa-oss libasound2-plugins

Generic Linux installer

Before we got actively involved in the creation of an Ubuntu installer, we packaged an experimental version of a Linux installer created for Scratch 1.3.1.   This installer uses David Thornburg and tookelso's perl script and overall structure. I was able to run it successfuly  on my system (Thinkpad x300 with Ubuntu Intrepid Ibex 8.10, 32-bit). A few things do not work:

1. MIDI (drum and note blocks)
2. .sb  file type association
   
3. Sound input/output. I get some errors but it could be just a problem with my system.
   

ALSA lib pulse.c:272:(pulse_connect) PulseAudio: Unable to connect: Timeout

startSound: snd_pcm_open: Connection refused

X connection to :0.0 broken (explicit kill or server shutdown).

ALSA lib pulse.c:272:(pulse_connect) PulseAudio: Unable to connect: Timeout

(NOTE: The sound issues may arise from the fact that the Ubuntu Squeak package is missing the vm-sound-ALSA file for some reason. -- JHM)

wget http://info.scratch.mit.edu/@api/deki/files/698/=Scratch1.3.1Linux.tar.gz -O Scratch1.3.1Linux.tar.gz

tar zxf Scratch1.3.1Linux.tar.gz

cd Scratch1.3.1Linux

perl scratch_install.pl  

Compiling

You should not need to recompile anything if you are using a recent version of Ubuntu (7.x or 8.x). However, if you do need to rebuild the binaries, the source code for the Squeak virtual machine is available at http://www.squeakvm.org/unix/ and the source code for the special Scratch plugins is available here.

Known Issues

Here are the known problems as of March 10, 2009. 

• Current versions of Scratch on Linux do not close when (X) or Alt-F4 is pressed.
  
• Drum and tone blocks make no sound due to lack of MIDI support. Some users have explored using TIMIDITY to support MIDI on Linux, but that appears to create other sound problems due to contention for the sound device.

We could use some help from the Open Source community with...

 Sound issues...

I'll try to summarize where we are with the sound issues in Ubuntu 8.0x -

First, a bit of background about Scratch: Scratch runs on Squeak, which is written in smalltalk, one of the first object oriented languages.  So Scratch is an 'image' that runs in a squeak virtual machine built for a particular OS.  Squeak is an Ubuntu package but we don't use the one from the repos - our Scratch package installs its own copy of the Squeak VM.

There are two major issues having to do with sound - playback and recording of sounds, and playback of midi sounds.

1. Playback and recording of Sound.  Scratch has two plugins to play sound and can use one or the other - an Alsa plugin and an OSS plugin. Based on our research, it seems like ALSA is the interface that will last longer into the future.  The Alsa plugin works on current versions of Fedora, Ubuntu 7.10, and the linux underneath OLPC's Sugar, but seems to have stopped working as of Ubuntu 8.04. We heard there were some changes to the sound system starting in 8.04 that we think might have broken it (introduction of  pulseaudio?).  Is there information about this in the community that might be useful / relevant in troubleshooting this? 
When trying to play sound via the Alsa plugin, we get the following:

  Playback will return error:
    "soundStart: snd_add_pcm_handler: Function not implemented"
  Record will return error:
    "sound_StartRecording: snd_add_pcm_handler: Function not implemented"

The latest package is working via the OSS plugin, but doesn't seem like a long term / clean solution - or is it?

2. The midi stuff (lower priority, but a bug we'd love to squash)
We don't know of a good way to play midi sounds from the note / drum blocks in Scratch on Ubuntu.  In Windows and Mac, there are libraries we can call that will do it.  On Ubuntu it seems murkier - we've found a midi synthesizer package called timidity that we think might be the solution, but we're kind of hung up on how to get the midi commands to it. Here's how our lead programmer summed it up:

If you can help us solve these problems, we'd love to hear from you on this thread:

http://scratch.mit.edu/forums/viewtopic.php?id=21&p=3 

Thanks for reading!