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

PC xfer still not working

Well I completely rewrote the code. And surprisingly, it looks pretty similar to what I did before. I moved the store/transfer routine out of (being called from) the ISR to the main loop. As soon as the ISR detects a...

PC xfer working now, timing in order

Welp I pretty much solved the big problems I encountered over the past couple weeks. Ground issues — turned out I was attaching ground of one interface to Vdd on another interface. That was solved by actually...

more hardware

When in doubt, just throw some more money at the problem! 🙂 Actually, I’m kidding. But I do have the Parallax USB2SER on its way — maybe the USB will be much faster, buffered, and more reliable. Those...

still no better

Well I’ve decided that my current approach just isn’t improving the situation. And despite help from a lot of people, I’m no better off than I was a few weeks ago. I happened to stumble upon...

Found one issue

Well, within an hour or so of getting my new LogicPort logic analyzer hooked up, I’m at least noticing some symptoms that I haven’t seen before. The drive is putting out(or the logic analyzer and my sx is...

new pictures

 

As you can see above, we have a “10” (4 us), another “10”(4 us) and a “1000”(8 us) chunks of data.  Little noisy there.

more testing

so I put the amiga floppy back on the amiga, and the amiga reads disks no problem.  Glad to see that my drive hadn’t fried through all my messing around. I haven’t seen valid MFM coming from the drive in so...

added commands

So I’ve added commands to support forward/backward stepping and upper and lower sides. R for Read D for Dump F/B for stepping either Forward or Backward U/L for selecting upper or lower side. I’ve tested...

SX EOL

I hate when this happens. 🙂 The Parallax SX microcontroller line has reached production EOL. The owner of the SX design (www.ubicom.com) has given Parallax final notice that we are to place a lifetime buy of wafers. We...

java and portability

While I have some experience with Java, I’ve never tried to run my stuff cross-platform. Never a real need. While most of the Java stuff has yet to be written, I took some basic serial code and GUI stuff, and...