Entries filed under Hardware

Hacking the 276 in 1 JAMMA board

TL;DR: Someone else has done this already go here.

My super wife bought me a modified Ms Pacman cabinet which has the 276 in 1 JAMMA board in it now. I noticed immediately it had an SD card on it and needed to know if it could be modified in anyway. This post will grow over time as I find new details.

Hardware info

The JAMMA board appears to have an ARM CPU based on the few binaries I looked at.

SD Structure

Three partitions. 1 is /boot, 2 contains some configuration and start up scripts, and 3 is / with a typical Linux file structure.

Partition 1

TODO

Partition 2

Lots of interesting things here

  • clsemuv – looks to be a build of the GP32 version of MAME
  • xemu – some sort of binary based on strings it seems to be a combination of sdlmame and pinmame
  • xhidev – another binary – looks like its used to control the other binaries
  • xrunmv – yet another binary – this seems to be a build of the LemonLauncher.
  • run.sh – tiny bash script which runs xrunmv
  • roms/ – symlink to /usr/roms – this directory is present on parition 3
  • nvram/ – directory containing .nv files for each ROM file
  • wavs/ – symlink to /usr/wavs
  • xrun/ – symlink to /usr/xrun

Partition 3

This seems to be the bulk of the Linux installation. It has all the usual unix directories here.

From some files in etc/ I think that partition 2 gets mounted at /sdcard during boot

Backing Up Your SD Card

The SD card has a special bootloader which needs to be “fused” with the SD card after it is imaged otherwise the system won’t boot.

To do this you need a few things:

  1. SD-Flasher: Get it from here: https://code.google.com/p/mini6410-debian/
  2. The correct SDBoot image for your JAMMA board. Some folks at the Arcade Museum forums have extracted these from their SD cards and posted them. There are 2 versions which I have uploaded here for your convenience. SDBoot 1.1 or SDBoot 1.21
  3. An image of your existing SD Card: Do this with DD or the imaging tool of your choice
  4. A new SD card – You might be able to use a larger or different SD card but I bought the identical card that came with my board on Amazon.

To do it:

  1. Image your arcade image on to the new SD card (I did this with dd)
  2. Start of SD-Flasher
    1. Pick the SDBoot bin file
    2. Click Scan!
    3. Pick the right card out of the list
    4. Click Fuse
  3. You’re done!

Previous Work

Some folks on the Arcade Museum forums have actually done all this work already. One of the members there summarized most of the work on this thread:

http://forums.arcade-museum.com/showthread.php?p=2417021#post2417021

Using EZCap EzTV668 DVB+ receiver for SDR on Mac OS X 10.7

There has quite a bit of buzz about the RTL-SDR project that is going on over at reddit on the rtl-sdr subreddit. Most of it has been about using the RTL2832/e4000 devices under Windows and Linux. Since I primarily use Mac OS I decided to cobble together the various hints of other people who have successfully used the devices on Mac OS and document them in a gist on github:

https://gist.github.com/2874757

Update: After some feedback on reddit for the previous gist I decided to revisit my build to that I would have a more up to date version of GNURadio. After much hacking I came up with these directions for getting GNURadio 3.6.0 working on 10.7:

https://gist.github.com/2eb4ff8e240164d0f751

After following those directions you’ll want to then install the rtl-sdr driver and then gr-osmocomm so that you’ll be able to use the RTL tuner with gnuradio.