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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

On speed optimization

The theoretical limit, assuming 300rpm drives, is 200ms per track. Or 400ms per cylinder, or 32 seconds per disk. Most attempts read slightly more than one track. I read 16,384 bytes, or 262ms worth. Right now, if I...

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Amiga Floppy

Changes to the PC side

With more and more things pointing to the PC, I’ve decided to really reduce the amount of work the PC has to do in its receive loop. I looked at Marco’s because his was designed to run (albeit in dos/dos...

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Amiga Floppy

Commands A and B implemented and working

Ok.  I got two commands A and B implemented and working. Command B from the PC instructs the SX to enable interrupts, and get ready to receive a track into fram.  This command will eventually be expanded to actually...

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Amiga Floppy

new isr thoughts

While this new ISR is indeed easier to understand and much more simple, I can’t help but remember what else my ISR used to do for me. The four things I really lose are: 1> Any type of double 1’s protection...

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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...

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Amiga Floppy

new timing image

I think this is timing from like 97 or so, and this is pretty good. I’ve switched to 93 for the time being, because I’ve had the best results with that. This still shows accurate reading of this particular...

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Amiga Floppy

progress on windows side

I put some time into the windows program that makes this whole thing tick tonight.  When I first started this project, I started with Marco’s afr.c, and pared it down to the bare necessities.  Then, I modified...

36 views
Amiga Floppy

recent status

Well, I’ve put a decent number of hours in on the project over the last couple weeks. I’ve mostly been “spinning my wheels” because I haven’t made much progress, but I think I’ve...

36 views
Amiga Floppy

even first or odd?

Despite having a couple different official sources, both AFR.c and floppy.c from the fellow amiga emulator says that the even bits come before the odd bits. This is true in the sector header decoding as well as in the...

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Amiga Floppy

interesting results

OK, I’ve applied the “double 1’s” fix that I talked about earlier today. This definitely helped things. I think my results are quite possibly the best I’ve seen them yet. Now, my SX...

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