Toni Westbrook dot Com

The Joy of Computer Science and Engineering

Thanks to a few nice, quiet hours I had tonight, I was able to do some Shredz64 development. One thing I quickly noticed at the ECCC convention last month was that Shredz64 is too hard for new players. The timing is different from Guitar Hero, and is pretty demanding on top of that, so unless you’ve been playing for a while, it’s pretty hard. This was where it was nice to see other people using it, as its hard to judge the difficulty of something you’ve been playing for a year.

So to combat this issue, I’ve added the choice to play a track in either “Easy” or “Hard” mode when selecting the song by pressing green or red, respectively.

Selecting hard plays the track at the same difficulty as before, but selecting easy plays the track much more leniently - the notes are the same, but the note matching gives you an additional 10 pixels above and below what is considered a valid note hit in hard mode. This will hopefully make the game a little more approachable for new players coming from playing Guitar Hero.

Live Demo - TPUG’s World of Commodore Expo

Also - just a quick announcement, I will be demoing Shredz64 and the PSX64 interface, as well as selling a few PSX64s at the upcoming World of Commodore Expo hosted by TPUG in Toronto on December 6th. Even if you’re not interested in Shredz64, I urge you to check out WoC, they have quite a few demos, lots of tables with great Commodore stuff for sale, and knowledgeable and friendly people to talk to. Toronto is always a fun place to visit as well, so make a weekend of it! Hope to see you there!

In my quest to collect a massive number of vintage and non-x86 machines, I recently picked up two Silicon Graphics workstations. I was pretty excited about this - as a teenager I had always been in awe of SGI and the amazing 3D their machines pumped out. As the originators of OpenGL and creators of some of today’s fastest supercomputers, SGI is one impressive organization.

The Operating System

One of the cool things about SGI stations besides their fast as hell (at the time) MIPS RISC processors is their operating system, IRIX. IRIX is a UNIX designed for the MIPS line and an X custom tailored to the SGI graphics chipset.

Photo of IRIX screen running a demo, GIMP, and a terminal

Another great feature of IRIX is built in clustering using array services. Like all clustering, this allows you share the processing power and memory of multiple IRIX workstations to accomplish tasks more quickly. Being an older OS, I was nervous the process would be difficult, but it wasn’t bad at all.

The following is what I did to create my “Excelsis” cluster, consisting of my two SGI workstations, Metatron and Gabriel:

1. Install Array Services - array services can be found on the operating system disks that come with your workstation.
2. Configure Your Array - IRIX comes with an arrayconfig script to generate the array configuration file, but chances are you’ll need to tweak it anyway, I find it easier to simply create the file in its entirety. The configuration file can be found at “/usr/lib/array/arrayd.conf”.

   Each array this machine participates in must be defined in this file. The first is normally an array labeled “me” which consists only of the localhost. Any further arrays require a name, plus a list of all machines in the array, which each need their own label and IP address or address to contact them at.

   array me
        machine localhost
   
   array excelsis
        machine metatron
             hostname "192.168.0.15"
        machine gabriel
             hostname "192.168.0.16"
   

   According to the documentation, quotations are necessary for hostname. As can be seen, I have defined an array called “excelsis”, with two machines, one named “metatron” and one named “gabriel”. I then specified the IP address of each machine.

   The default arrayd.conf file will define a number of array commands that can be run from the terminal. These are all well known UNIX commands such as top, ps, and who, only they can be run on the array as a whole, as opposed to just the local machine. E.g., running “array who” would list all users logged into the array (i.e. any machine connected to the array). Leave these commands where they are and jump to the end of the config file.

   The end of the configuration file contains a “local” identifier that contains settings and defaults for array services running on the machine, such as the port array services listens on and the default array for array commands (remember, your machine can participate in more than 1 array. If you run an array command without specifying an array, it will default to the one specified here). You’ll want to change “destination array” to be the name of your default array. In my case, I changed it to “excelsis”. That’s it for this file!

3. Configure Array Security - By default, your array will be configured to not allow connections from remote machines. This allows messages to be passed via MPI between programs running on your machine, but doesn’t allow for clustering. Edit the “/usr/lib/array/arrayd.auth” file, and you should see “AUTHENTICATION NOREMOTE”. You’ll want to change this to “AUTHENTICATION NONE” if you want any machine to be able to connect to your array (not secure, but may not be an issue if you’re running behind a firewall), or “AUTHENTICATION SIMPLE” if you’d like to setup private keys for each machine. If you go the simple authentication route, you’ll need to specify “HOSTNAME machine1.domain.com KEY 0×3817382771948″ where machine1.domain.com is the address of the machine, and the hex string following KEY is the private key. You’ll need to specify this for all machines. These keys must match per machine on all machines in the array.
4. Autostart Array Services - Now that you have your array services configured, you can tell IRIX to start it on bootup by enabling it in chkconfig. If you aren’t familiar with chkconfig, it is a special utility that configures whether various daemons should autostart at bootup or not. You can see a list of which daemons are currently set to start by running “chkconfig” with no arguments. To autostart array services, type “chkconfig array on”.
5. Rinse, Repeat - You’ll need perform the above steps on every machine participating in the array. Assuming you have NFS starting before your array, I don’t see any reason why these configurations couldn’t be symbolically linked to one central configuration, but if you ever wanted machine specific settings you’d be out of luck. I simply edited the files on both my SGI workstations.

At this point, you can run an “array who” to see all people logged into your array and “array ps” to see all processes running on all your clustered machines. The fun really begins for programmers at this point, as you can make use of the MPI libraries to share tasks across multiple nodes in your cluster for parallel processing.

While IRIX is on its way out and the chances of needing to setup a cluster is slim, it can be a fun little project if you have a few SGIs kicking around. It would also be interesting to see the compatibility of passing MPI messages between IRIX and non-IRIX clusters. A project for another day!

I’m a pretty big fan of games in general. I love playing them, making them, watching the impact they make - everything about the industry is pretty awesome. While I was certainly a Nintendo kid, gaming really started for me on the Commodore 64, and enjoyment grew into a true appreciation with adventure games and my first PC, as I talk about here.

Where Did the Adventure Go?

The gaming market has changed in some very distinct ways over the years for a number of reasons. One of these changes that has been talked about quite a bit is the decline of the adventure game market. These games used to dominate, and now are the stuff of homebrew projects and small corners in software stores. While it’s sometimes difficult to discern if the market shapes corporate decisions or vice versa, we are indeed in a place where giants like Activision abandon clearly sought titles (read: Ghostbusters) as the profit margins are deemed unworthy by their market research and finance personnel. A business must survive and prosper to continue to push out product, but there is that point where an organization becomes more concerned about their profit than their product. And we are in no shortage of companies that subscribe to these views.

The Gallant Few

On the other side, there are those gaming companies that understand they can make a profit but still have a soul - staying true to the heart of the gaming community. I speak of Telltale Games, makers of the Sam and Max series, Strong Bad’s Cool Game for Attractive People, and the upcoming Wallace and Gromit’s Grand Adventure. They are a group of people whose passion lies in adventure games, even in a time where the typical market research would suggest this is not as profitable a route as creating a string of Call of Duty or Grand Theft Auto clones. Makes sense, since Telltale was founded by veterans from LucasArts, the company that at one time had produced masterpieces such as the Monkey Island series, Maniac Mansion, Day of the Tentacle, and yes - Sam and Max Hit the Road.

Screenshot from Sam and Max Season 2 Episode 3: Night of the Raving Dead

Having played through both season 1 and season 2 of Sam and Max, and the first episode of Strong Bad, it’s clear to me that Telltale puts out simply awesome games. Packed with humor, beautiful illustration, and quality gameplay, these adventures are truly fun to play. They also go to show that adventure games are not confined to the retro, homebrew, and Myst clone market.

Give Them a Visit

If you haven’t yet, take a moment and check out their site, there are even some free downloads to get a taste of what their fare is all about. And if you like what you see, give them some money! I know I for one would like to see a little more diversity in my gaming selection, but it can only happen if we support companies that are in it for the games, not just the revenue.