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...

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interesting results

OK, I’ve applied the “double 1’s” fix that I talked about earlier today. This definitely helped things. I think my results are quite possibly the best I’ve seen them yet. Now, my SX...

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...

even first or odd?

Despite having a couple different official sources, both AFR.c and floppy.c from the fellow amiga emulator says that the even bits come before the odd bits. This is true in the sector header decoding as well as in the...

found bug last night

With this new FPGA solution, certain tracks would result in what I call a “short read.”  A short read is any received track that contains less than 28,125 delta T’s, aka pulse times.  Given a certain...

new design on SX software

Welp, I’m having trouble tweaking my existing SX code. If I modify the timing of the current code, I’m getting all garbage output — even adjusting small amounts to one side or the other, produces much...

USB uart send and receive

Good news, good news. After banging my head on the same problem for the last three hours, I’ve finally made some more progress. Using option #2 from the previous post, I’ve written two non-isr based software...

Timeline

I’ve put together a time line of events starting from November 2004, the initial idea.

CLICK THE ABOVE IMAGE FOR A FULL SIZE VERSION.

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...

minor success at 2:00am

well I’ve got MFM flowing from the PC drive now.  A couple of things: Pins 10 and 14, the pins I’ve been using since last night, appear to be correct. Pin 10 is the motor lead.  Dropping a corresponding SX...

sync on data

The more and more I play with this I find that I’m limited with visibility. Its tough to debug when you constantly have to deal with this overhanging problem : The data arrives at my hardware, and to the PC...