MP3-Man | During my senior year of college, I was on a team of three students who designed and built an MP3 player with a Texas Instruments DSP development kit. The development board included a TMS320C31 DSP processor, and a very small amount of RAM. Harware modules designed by the team include a stereo 16-bit D/A converter and output amplifier, interfaced though the DSP serial port; a high-speed ISA serial transmitter card for a PC, which streamed compressed MPEG layer 3 data to the player; and a 128 kilobyte RAM expansion board for the processor. I translated source code for a public domain MP3 player from C into 'C30 assembly language, and heavily optimized the code to achieve real-time decoding speed on the slow 25MHz chip. |
FA Sound Card | As my first project with real digital logic interfacing, I designed a 16-bit sound card during study hall in high school. I soon purchased the necessary parts and built the board. After several days of debugging, I got both the mono 16-bit A/D input and stereo 16-bit D/A outputs working. I wrote a couple of small programs to loop audio signals from the input to the outputs, add simple echo effects, etc. Eventually I went so far as to write a tiny driver for a fantastic sample-based music playing program for DOS called ModPlay. The driver had to fit in 64 or so bytes, and I had to manually type the hexadecimal machine code in an ASCII configuration file. It sounded great. |
Checkbook | A long time ago, I wrote a checkbook balancing utility in DOS which categorizes transactions and generates user-configurable data reports. It was originally custom written for Edgewood Animal Hospital, but I continue to use it personally to this day. Recently I fixed its Y2K bugs to make the software compatible with the new millenium. |