Brad's comments on the world of technology...

Blog Category: Software

Crowdsourced Zynq FPGA board

This is interesting.  A crowd sourced FPGA board with a Xilinx Zynq;  Basically Xilinx FPGA fabric with a hard ARM A9 CPU. It looks like you'll need to break out board as well to get reasonable connections (USB, HDMI).  Seems like a lot can be done with that.  I have not

Ubuntu upgrades. wow!

I have a couple of machines running Ubuntu. More and more lately. One machine at home was running Ubuntu 7.04 and mythtv. I was loath to change it because it was working and I hate having to type "ssh" when I'm watching tv. But, I finally did it over the holidays. First I upgraded to 7.10, which was a pain. 7.04 is not longer supported and

pcc (portable c compiler) lives again!

Two interesting things happened this week - the "R" programming language was talked about in the mainstream press. - I discovered that the openbsd folks are working on using a non-gcc C compiler (pcc). Turns out in the non-linux unix world there is not so much love for gcc. This makes some sense. gcc is huge and hard to

My experiment with Mythtv

I love my tivo. I've added a big disk to it. But I want to see more of my "personal media" on the tv (pictures, movies, etc) so I decided to make a Mythtv box. I made a nice new pc in a "stereo cabinet like" box. I used a motherboard with built in HDMI output (very nice) and a 64 bit AMD cpu. I got all this from Mwave. Motherboard:

Firefox bookmarks

Just a quick note on bookmarks. I use several laptops, a common machine at home and a workstation at work. This can sometimes get confusing when I save web bookmarks in various different places. I recently discovered "foxmarks". I only used Firefox, and foxmarks is an extension which syncs up my bookmarks everyplace I install it. It's

Modifying read-only file systems in an embedded system

It's often a good idea to make the root file system in a embedded system read-only. If you do this and only make changes to files in a ram disk (mounted under /tmp, for example) the device will always come back to a known state when powered up. This is a nice feature and often a requirement. But sometimes you need to make changes which

RCU in the linux kernel; an alternative to reader-writer locks

I ran into something in the announcement of the 2.6.19 kernel called "sleepable rcu". I found this wikipedia entry for rcu. It gives some nice background on rcu's. I don't normally place much credence in wikipedia pages but this one seems reasonably good. And it explains why RCU's are a better alternative to multiple-reader-single-writer

HTML from lisp

(aside: this is a pretty funny intro to lisp casting spels in lisp) Generating HTML from lisp is nothing new. Many people have done it and there are lots projects on the web using it. There's also a lot of interesting XML/HTML lisp code floating around. It turns out that XML and HTML lend themselves rather well to symbolic processing. I've

A quick Scheme / embedded-system example

Usually when I find myself fighting to prove a point it's usually becuase it's a loosing battle and my ego just won't let go. But let's assume you actually might be interesting seeing why a simple lisp like scripting language might be intesting. I wanted to change the behavior of a display terminal. I wanted it to have a list of times (hours

Scheme + Bogl + SDL = simple, quick embedded UI

I have been struggling with a way to make a simple user userface for an embedded system with a 640x480 LCD but no keyboard or mouse. The machine only has 64mb of ram and wants to run largely out of ram. This eliminates things like X windows, TK, etc... And, I wanted to be able to hack up experiments quickly. I originally tried Java, but it

Warm Start

It's important to note up front that I don't know what I am talking about. At least when it comes to Lisp. There are some things I on which I can speak authoritatively, but this isn't one of them. Having said that, I am a obsessed with lisp and things lisp. It began when I read first saw some adventure source code in

Why is Software Development Still Magic?

I regularly talk to companies who have software development problems - late schedules, too many bugs, unhappy customers. I sometimes marvel when people act as if software development was some magic process which was impossible to understand or control. My experience is that's not magic and is not that hard to control. I'd like to share some

Oh those crazy young people in Europe...

Apparently every four years young hackers in Europe get together and make a sort of tent city. It's called "whathehack" It looks like fun, at least if you like laptops and beer