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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

Canada Post sucks

So I made the mistake of having an Amiga book shipped from Canada using Canada Post Expedited USA shipping.  It was dropped off at a post office on Nov. 17th in Mississauga, Ontario.  Now Mississauga is about 300 miles...

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Amiga Floppy

USB uart send and receive

Good news, good news. After banging my head on the same problem for the last three hours, I’ve finally made some more progress. Using option #2 from the previous post, I’ve written two non-isr based software...

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Amiga Floppy

Ground issues

Although I’ve been attempting to have a common ground for this whole project — I’m not sure that is going to happen. At least not at this stage of the game. I tried connecting the ground off the floppy...

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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 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

mid-january status

So here’s where I’m at: I know my memory read and write routines are good.  I calculate a checksum as I’m writing the data, and on the output of that data to the PC, I also calculate the checksum. ...

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Amiga Floppy

Creating more test disks

From both Tim’s suggestions and from a reinforcement from Agans’ Debugging book, Chapter 6, “Divide and Conquer”, they suggest to “Inject Easy-to-Spot Patterns”. And of course, I knew...

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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...

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Amiga Floppy

minor success at 2:00am

well I’ve got MFM flowing from the PC drive now.  A couple of things: Pins 10 and 14, the pins I’ve been using since last night, appear to be correct. Pin 10 is the motor lead.  Dropping a corresponding SX...

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