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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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Amiga Floppy

great performance increases

Today I’ve worked on optimizing the performance of the AFP reader and have made great strides. My original track times were nearly 475ms. This was 300ms reading the actual disk, 125ms transferring, and process...

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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...

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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

reworking my uart

Well I rewrote my recv and send uart, and with the help of my logic analyzer, I’ve tuned them up pretty good. I’m getting some transfer errors, somehow, and I think its related to buffer size. I read a disk...

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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

updates with FRAM access

My initial attempts to write to the FRAM used SX/B commands like SHIFTIN and SHIFTOUT. These operated at a slow rate of about 83kbits/s. It did work and functioned as a good test of the hardware setup. Now that...

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Amiga Floppy

data rate vs throughput

Although I’m transmitting from the Parallax SX microcontroller to the PC via USB at a data rate of 2mbps, the actual throughput is much less.  First, there is some overhead, namely start and stop bits, which is...

68 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...

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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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Minor problems on techtravels.org email

I recently discovered a problem where email directed to techtravels.org accounts was bouncing. It’s been fixed. If you’ve emailed something over the last couple months and didn’t get a reply, please...

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