Postcard #2 - Getting Information

Now that I've started pursuing this crazy idea, what next?

Well, I've got several books handy from when I started working with Asterisk, most of which I got used off of eBay:

• T1 - A Survival Guide
• Fundamentals of Digital Logic with VHDL Design
  
• Digital Electronics Demystified

I have since found out that there is a new edition of the VHDL book, but I'm holding off for now.

I even went and bought a cool little breadboard training kit from Radio Shack. Glamorous? No. Helpful with getting to know electronics after a 15+ year hiatus? Yes. Not a bad $70 to spend to play with all sorts of transistors and IC's.

I spent a fair amount of time poring over the source code and schematics of my quad T1 cards. They are a clone of the Digium Tormenta2 PCI Quad T1 board. They even use the same drivers, except that the designer of my board has made some modifications. Anyway, that project lead me to some interesting information:

• Zapata Telephony Project
• Current Zaptel Drivers
  
• pbxhardware.com drivers
• Dallas Semiconductor (Quad T1 Framer IC)
• Xilinx PCI Controller IC
• Spartan FPGA (Field Programmable Gate Array)
  

This was almost too much information! However, I digested it as best I could. It turns out that I was able to learn quite a lot about embedded software, including the relationship between hardware, firmware, and software. I also was introduced to FPGA's and VHDL, both of which I had never heard of. Very cool topics.

Recently I purchased a few more books, as well as downloading O'Reilly's Linux Device Drivers 3rd edition. Of course, where possible I bought used on eBay or half.com:

• Designing Embedded Hardware
• Understanding the Linux Kernel
• Linux Kernel in a Nutshell
• Programming Embedded Systems with C and GNU Development Tools
• USB Complete

I got the Linux books because kernel programming and embedded systems are closely related to getting down and dirty with writing software, drivers, firmware, etc. that get seriously intimate with the hardware. I needed to start somewhere, so there I did. If anyone has other suggested reading then I'd be willing to check it out. I'm a book addict.

One other place I looked that opened up a whole new can of worms, in a good way, is David Rowe's website. I've only just scratched the surface on his offerings, but the Free Telephony Project looks totally cool.

At this point I've just started reading about USB's capabilities. It has three different bus speeds, and I think the two higher speeds will be adequate but I won't know until I really get into this hip-deep.

My next postcard will be from my journey through OSS for creating, designing, and testing digital circuits and creating PCB's. (Printed Circuit Boards.)

-MC