standard page 4 - Dave's Blog

ThinkGeek Bluetooth Retro Handset Review

2008 Mar 23, 1:25

I ordered a ThinkGeek Bluetooth Retro Handset to use at home. When I come home I plug my phone in to charge in my room, but then I can't hear it ring elsewhere in the hosue. The idea was to take this handset which wirelessly connects to cellphones via bluetooth and place it in another part of the house so that I can tell I'm getting an incoming call. The only issue I have with that setup is that it ringing isn't any louder than conversations held over the phone, that is, the ringing is a little quiet.

The handset pairs with cellphones in the same manner as any other handset over bluetooth. It has an internal rechargeable battery which is charged via a standard USB port built into the base of the handset and it comes with a USB cable. Next to the USB port is the only button on the phone which is pressed to answer a call, hang up a call, or begin voice dial, held down to turn the handset on and off, and held down longer to begin pairing with a cellphone. There's a blue LED in one of the holes in the microphone portion of the phone which blinks to indicate if its on or trying to pair. Transitioning between on, off, and pairing produces a cute sound and a change to the LED.

Overal I'm pleased with its simplicity and use of common parts although I wish there was a way to adjust the volume of the ring.

thinkgeek bluetooth cellphone phone product handset

URI Addressable Text Adventure Games

2008 Mar 2, 9:18

This post is about creating a server side z-code interpreter that represents game progress in the URI. Try it with the game Lost Pig.

I enjoy working on URIs and have the mug to prove it. Along those lines I've combined thoughts on URIs with interactive fiction. I have a limited amount of experience with Inform which generates Z-Code so I'll focus on pieces written in that. Of course we can already have URIs identifying the Z-Code files themselves, but I want URIs to identify my place in a piece of interactive fiction. The proper way to do this would be to give Z-Code its own mimetype and associate with that mimetype the format of a fragment that would contain the save state of user's interactive fiction session. A user would install a browser plugin that would generate URIs containing the appropriate fragment while you play the IF piece and be able to load URIs identifying Z-Code files and load the save state that appears in the fragment.

But all of that would be a lot of work, so I made a server side version that approximates this. On the Web Frotz Interpreter page, enter the URI of a Z-Code file to start a game. Enter your commands into the input text box at the bottom and you get a new URI after every command. For example, here's the beginning of Zork. I'm running a slightly modified version of the Unix version of Frotz. Baf's Guide to the IF Archive has lists of IF games to try out.

There are two issues with this thought, the first being the security issues with running arbitrary z-code and the second is the practical URI length limit of about 2K in IE. From the Z-Code standard and the Frotz source it looks like 'save' and 'restore' are the only commands that could do anything interesting outside of the Z-Code virtual machine. As for the length-limit on URIs I'm not sure that much can be done about that. I'm using a base64 encoded copy of the compressed input stream in the URI now. Switching to the actual save state might be smaller after enough user input.

zork frotz interactive-fiction zcode if technical uri fragment

IPv6 Roundup: Address Syntax on Windows

2008 Jan 9, 11:34

IPv6 address syntax consists of 8 groupings of colon delimited 16-bit hex values making up the 128-bit address. An optional double colon can replace any consecutive sequence of 0 valued hex values. For example the following is a valid IPv6 address: fe80::2c02:db79

Some IPv6 addresses aren't global and in those cases need a scope ID to describe their context. These get a '%' followed by the scope ID. For example the previous example with a scope ID of '8' would be: fe80::2c02:db79%8

IPv6 addresses in URIs may appear in the host section of a URI as long as they're enclosed by square brackets. For example: http://[fe80::2c02:db79]/. The RFC explicitly notes that there isn't a way to add a scope ID to the IPv6 address in a URI. However a draft document describes adding scope IDs to IPv6 addresses in URIs. The draft document uses the IPvFuture production from the URI RFC with a 'v1' to add a new hostname syntax and a '+' instead of a '%' for delimiting the scope id. For example: http://[v1.fe80::2c02:db79+8]/. However, this is still a draft document, not a final standard, and I don't know of any system that works this way.

In Windows XPSP2 the IPv6 stack is available but disabled by default. To enable the IPv6 stack, at a command prompt run 'netsh interface ipv6 install'. In Vista IPv6 is the on by default and cannot be turned off, while the IPv4 stack is optional and may be turned off by a command similar to the previous.

Once you have IPv6 on in your OS you can turn on IPv6 for IIS6 or just use IIS7. The address ::1 refers to the local machine.

In some places in Windows like UNC paths, IPv6 addresses aren't allowed. In those cases you can use a Vista DNS IPv6 hack that lives in the OS name resolution stack that transforms particularly crafted names into IPv6 addresses. Take your IPv6 address, replace the ':'s with '-'s and the '%' with an 's' and then append '.ipv6-literal.net' to the end. For example: fe80--2c02-db79s8.ipv6-literal.net. That name will resolve to the same example I've been using in Vista. This transformation occurs inside the system's local name resolution stack so no DNS servers are involved, although Microsoft does own the ipv6-literal.net domain name.

MSDN describes IPv6 addresses in URIs in Windows and I've described IPv6 addresses in URIs in IE7. File URIs in IE7 don't support IPv6 addresses. If you want to put a scope ID in a URI in IE7 you use a '%25' to delimit the scope ID and due to a bug you must have at least two digits in your scope ID. So, to take the previous example: http://[fe80::2c02:db79%2508]/. Note that its 08 rather than just 8.

roundup ip windows ipv6 technical microsoft boring syntax

FoaF on my Homepage

2007 Oct 14, 3:12I've updated my homepage by moving stuff about me onto a separate About page. Creating the About page was the perfect opportunity to get FoaF, a machine readable way of describing yourself and your friends, off my to do list. I have a base FoaF file to which I add friends, projects, and accounts from delicious using an XSLT. This produces the FoaF XML resource on which I use another XSLT to convert into HTML and produce the About page.

I should also mention a few FoaF pages I found useful in doing this:

• FOAF Vocabulary Specification - The standard on which I based my XSLT to add in info from delicious.
• FoaF Explorer - Turns any RDF XML FOAF resource into a webpage with links to the other people, projects, etc mentioned in the FOAF file.
• FoaF-a-Matic - I used this to produce my base FoaF file.
• RDF Validator - This is the closest thing I could find for validation. It does RDF in general but unfortunately not FoaF specifically. I found two links to sites that are down or dead that claimed to do what I actually wanted.

technical xml foaf personal xslt xsl homepage

Date Time Formats

2007 Sep 27, 2:17Starting on a new simple project I wanted to get the history of my Delicious links. Delicious has an export tool available via the settings section so I thought I'd try that. However, the links aren't exported in XML not even in XHTML but rather in HTML. Shocking. An example:

"Don't Tase Me, Bro!" (UF Student Tasered Remix)

Remix of the 'Don't tase me, bro!' guy getting tasered.At this point I'm already not going to use this file because its in HTML but I'm even more disgusted by those date time values. Raymond Chen of the Old New Thing posted about recognizing timestamps and timestamp sentinel values. From the first blog post and with the use of a calculator for base conversion one can tell that those are UNIX style timestamps counting the number of seconds since 1970.

It reminds me of my hatred for the MIME date time format I developed working on my webpage's server side parsing of atom and RSS. Atom is of course my favorite as Atom uses the Internet date time format described in the following documents. Here's an example of one 2007-09-27T020:50:00.000-08:00

• W3C Recommended Date and Time Format
• IETF: Date and Time on the Internet: Timestamps
• XML Schema dateTime

On the other hand the evil and villainous RSS uses the MIME date time format now described in the more recent IETF MIME standard. Here's an example Thu, 27 Sep 2007 20:50:00 -0800
The Internet date time format has the advantage of being so easy to sort. An alphabetic sort with normal C-style collation rules of strings containing Internet date times will also sort them chronologically. This is not the case for the MIME date time due to the preceding day of the week and the spelled out month name. This also means that when producing these you have to figure out the day of the week and when parsing them you have to match month names rather than just parsing out numbers. Anyway now days if I see mention of a date time in a new proposed standard or spec I be sure to point out the numerous advantages of the Internet date time format.

date xml html feed time technical date-time code atom rss