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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Minor problems on techtravels.org email

I recently discovered a problem where email directed to techtravels.org accounts was bouncing. It’s been fixed. If you’ve emailed something over the last couple months and didn’t get a reply, please...

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...

Finally had some luck with FPGA board

So I bought an FPGA eval board and a book on Verilog awhile back.  I made some progress learning things, and had some simple things like UARTs, writing to the LCD, and even some small VGA software(hrrrm, maybe I should...

Found another UART timing issue

Ok. A post or two back, I mentioned that I wanted to rework the receive UART because it wasn’t working perfect. I fixed that, and now it’s reliably receiving. I also mentioned that my sending uart code was...

Good news good news. First perfect .adf

Good news indeed! I’ve managed to create a fully functioning .ADF from a floppy.  I matched the output from my hardware/software combination with a “transdisk” output, and it matches exactly. I used...

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...

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...

memory chip mounted

Welp, I got impatient, and went to Radio Shack to buy their soldering station. I still have mine coming in the mail, but its ground from Arizona, which may as well be ground from Alaska. I soldered the header pins onto...

intermittent problem found

I was just putting some finishing touches on this before I started to actually use and archive some of my stuff.  To put it to an actual real world test. Anyways, I tested an ADF generated ADF  against an amiga...