techtravels.org

inital results on error correction

While I have yet to actually implement the full-scale error correction as I want to, I did some manual tests today. I basically took a track that I was erroring out on, and swapped in 1-bit away values for the bad bytes.  In some cases, it appeared...

Latest articles

Launch of HOPE Badge Computer project

This is the first post of many in this category. We have a project page giving the general goals of the project, but most of the hands-on action will happen here in the blog posts. For the latest status, reading these...

my checksum algorithm

So I’m using an XOR checksum to detect errors in the transfer between the SX and the PC.  I always thought it was a reasonably strong checksum, even though it’s still an 8 bit checksum. I found a neat...

more updates

I know I’ve been bad keeping you guys updated….. This doesn’t mean I haven’t been working on it, however. I recoded the ISR completely in assembly because I was just plain sick of the damn...

data rate vs throughput

Although I’m transmitting from the Parallax SX microcontroller to the PC via USB at a data rate of 2mbps, the actual throughput is much less.  First, there is some overhead, namely start and stop bits, which is...

changed from rxtx to jd2xx

Okey dokey. I’ve changed from rxtx to jd2xx.  rxtx didn’t support DTR/DSR flow control, which really is an absolute must for my application.  There would have to be hardware changes that I’d be...

new face of the amiga floppy project

You’d think that with the lack of posts lately that I haven’t been doing anything. BUT, in fact, I’ve been quite busy. I now have the entire floppy project on one single circuit board, the SX28...