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Amiga Floppy

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

logic analyzers

I’ve recently received a couple emails on additions to the logic analyzer page. Once I get some time to check them out, I’ll make the corrections. I’ve been super busy with life — switched jobs...

96 views
Amiga Floppy

losing data

I’ve been thinking more and more about how exactly I’ve been losing data. It’s alot of data. The worst case I’ve seen is about 140 bytes. This is 1120 bits, or 2240us. This is a LONG time for my...

96 views
Amiga FloppyInactive

more real world tests

So tonight, I put my new FPGA implementation of the amiga floppy project to good use.  I read some more of my collection of amiga floppies. GREAT NEWS. It’s working like a champ.  As a matter of fact, I selected...

96 views
Amiga Floppy

first two bytes of checksum bad

Despite the data being received 100% correct, the data checksum fails in certain cases. It’s always the first two bytes of the 4-byte, 32-bit checksum that are wrong.  The last two are always right.  What does...

96 views
Amiga Floppy

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...

96 views
Amiga Floppy

redesign of read routine

After skimming the patent I referenced in the earlier post, I’m starting to come to the realization that in order to have an effective floppy controller, I need to implement a decent PLL which can better track the...

96 views
Amiga Floppy

quick memory check

So on bootup, I now have the hardware do a memory check.  I basically take and write out a bunch of values to the memory, and then read them back and make sure they read back properly.  The values written are based on...

93 views
Amiga Floppy

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...

93 views
Amiga FloppyInactive

found bug last night

With this new FPGA solution, certain tracks would result in what I call a “short read.”  A short read is any received track that contains less than 28,125 delta T’s, aka pulse times.  Given a certain...

92 views