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

SX software progress

Welp, since I fine tuned the PC to very reasonable numbers, I figure a small overhaul of the SX code is in order too. I had somewhat of an epiphany working the on the SX, which I haven’t *really* looked at in...

more SX to PC tests

Although I think I’ve long had this working good, I did some more tests just to verify. Latest numbers: Each cycle is about 15.8us, 2us per bit, 8 bits, this sounds fine. This does confirm, however, what I...

migrated website to a new host

Over the last week, I migrated this blog to a new hosting provider. GoDaddy was such a pig and the site just ran like molasses when hosted by them. I couldn’t be happier with the switch that I’ve made, but I...

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...

Changes to the PC side

With more and more things pointing to the PC, I’ve decided to really reduce the amount of work the PC has to do in its receive loop. I looked at Marco’s because his was designed to run (albeit in dos/dos...

Success!@#

I hestitate to jump to conclusions, but I think I just passed a crucial first step in getting this to work!@#!# After adjusting some timing on my new code on the SX, I’ve found my first 0x4489 0x4489 pattern. This...

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.

MFMSanityCheck

While I’m hesitant to post this at all, this is a quick and dirty application I threw together, and I do mean threw, that will check for valid MFM bytes. See the previous post for the link to the actual bytes. It...

reading problems

I hate leaving projects for awhile.  Any more than a few days, and you lose the focus, you lose the insight, and remembering exactly where you left off can be a pain in the butt. This time, I’ve come back to a...

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...