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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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LCD Test image and pixel-level detail

So I’ve managed to get a semi-working test pattern image up on the LCD. Here are a couple shots: If we zoom in about 10 times, we can see how the LCD really works, on an individual pixel level: Pretty challenging...

motor speed variation tests

I collected roughly 1,000 index pulses from the Sony MPF920-E with one common floppy inserted. The motor speed variation was very very small.  I am impressed as to the accuracy. Across 967 index pulses, all were within...

first .adf written

Well, I’ve written my first .adf tonight! I threw together a quick routine on the PC side to query the SX for both sides and all the tracks. It generated a 901,120 byte .ADF file of a disk I had called...

Getting closer….

So a few versions later, trying some different failed attempts, I am finally starting to get a little closer.  Here’s the best video I’ve got so far, but my image is still scrolling. If I can fix the...

sanding a 556 timer IC to expose the die

So tonight, just for the fun of it, I decided to sand, by hand, a 556 timer IC. I just bought an extremely inexpensive microscope and was very interested to see what pictures I could get from it. Unfortunately, for me...

Using a 74HC132E to square up the wave

A nice gentleman from sci.electronics.* newgroup suggested I use a 74HC132 on his web page here.[local copy] Below is the result of using this design, it worked perfectly. Only required one IC, one resistor, and one...

error correction using hamming distances

I’ve been thinking for quite some time about error correction.  About using the structure of the MFM to our advantage.  I’ve come up with something although I haven’t implemented the idea yet. As you...