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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current read problems

It seems as though when I have a read problem, its normally minor, and is a single bit error. I notice that the errors have a tendency for 0s to be incorrectly interpreted as 1s. So I get AB instead of 2B, AB instead of...

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...

heat problems

As I alluded in an earlier post(s), my SX28 has been pretty warm. After doing a number of different tests, I’ve now ordered an infrared thermometer from amazon for $29.99. I want to find out exactly how hot this...

a little code review today

While my send UART code has been pretty solid for some time, I’ve always though my receive uart code needed doublechecked and worked on. I spent some time today just going through the code, graphing out some...

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...

Good news. Floppy now under SX control

OK, so I finally bit the bullet and have the floppy drive under direct SX control. I have my amiga power supply, which is a modified PC supply with harddrive leads powering the drive directly with +12v and +5v.  I also...

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...

Logicport screenshots and project file

I thought this might be neat to put up. Sorry about the high-res image but you lose too much when it compresses it. Click here for the screenshot. Also, I uploaded the .LPF project file which can be viewed for free with...

basic schematic

I put up a rough schematic of my design.  It’s not perfect, and will be updated in the near future, but if you are interested.
Click the image below for a full size image.

Timing image

I just wanted to throw this up here to show an example of how the timing is working on my project. Its working well. Top line is the input signal from the drive. Bottom line is the firing of interrupts, either from the...