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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...

keith
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Latest articles

Amiga Floppy

Hardware and code diagram

I’ve thrown up a PDF that shows the basic hardware setup. It also shows the flow of my software, which is very simple. I didn’t put the clock details on there such as how often the clock rolls etc because...

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Amiga Floppy

updates

I originally thought that the SX might be sending the data too fast for the PC to handle. As my last post mentioned, one full cycle is 12us, but who knows if this is during a disk-write, going into the cache, etc. I...

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Amiga Floppy

timing movie

I have uploaded a movie showing 30 seconds of input signal vs detected result. I checked this frame by frame and I didn’t find a single error. I still can’t figure out why I have output errors. Maybe you can...

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Amiga Floppy

I’ve played around a considerable bit from yesterday. There’s something very strange about the speed the PC can react in certain circumstances, and I can’t quite nail it down. Now I haven’t...

26 views
Amiga Floppy

new book

I picked up a copy of Reversing: Secrets of Reverse Engineering this past weekend. I have about 5 or 6 chapters read. All very good. It was published April 2005 or thereabouts, and so its much more updated than the book...

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Amiga Floppy

example files

I wanted to put up some example files. Note that a preceding “D” for dump and two delimiting 0xFF’s might exist in these files. Also an ending 0xFF 0xFF might exist. So two bad files below have exactly...

25 views
Amiga Floppy

vacation reading

While I’m on vacation this week, I’m reading a book about making your own circuit boards using Cadsoft’s Eagle. Eagle is a schematic capture and board layout program that seems pretty popular and...

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Amiga Floppy

Timing problems still?

I think I’m still having timing related issues. I have RTCC overflowing every 1.8us which I *know* is less than the 2us bit cell(or less than half the bit cell, if you take it to be 4us), but this seems to be what...

24 views
Amiga Floppy

java software progress

This morning I added MFM decoding, header and data checksumming and checking to the java client.  I was somewhat worried about doing the MFM decoding, but it was all worry for nothing. Once you wrap your head around how...

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