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

reworking my uart

Well I rewrote my recv and send uart, and with the help of my logic analyzer, I’ve tuned them up pretty good. I’m getting some transfer errors, somehow, and I think its related to buffer size. I read a disk...

mid-january status

So here’s where I’m at: I know my memory read and write routines are good.  I calculate a checksum as I’m writing the data, and on the output of that data to the PC, I also calculate the checksum. ...

Creating more test disks

From both Tim’s suggestions and from a reinforcement from Agans’ Debugging book, Chapter 6, “Divide and Conquer”, they suggest to “Inject Easy-to-Spot Patterns”. And of course, I knew...

first day back

You know, I always hate the “first day back” working on a project.  Things always seem to get screwed up between the time I last worked on a project, and that day.  Even if nothing has changed. Or so I say...

Parallel port access in win 2k

Accessing the parallel port directly under Windows 2000, XP, etc in a standard user app is not natively available, but there are a couple different solutions available. The free one I use is called WinIo, and it is...

Ground issues

Although I’ve been attempting to have a common ground for this whole project — I’m not sure that is going to happen. At least not at this stage of the game. I tried connecting the ground off the floppy...

Schmitt Trigger

Welp, after talking with some smart guys on forums.parallax.com, it looks like the Schmitt Trigger feature on the SX is going to allow me to get rid of my 74HC132 that I’ve spent at least a couple hours messing...

java software

I’ve been working on the Java software the last couple days. Trying to read from RXTX is producing only 3968 bytes per read.  It looks like my USB -> serial converter uses a “transfer size” of 4096...