techtravels.org
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
4 comments

Latest articles

Amiga Floppy

pullups

These are all 2us per division on the scope.  Top trace is the actual MFM, bottom trace is the entering and exiting of my ISR.  You should see an entry into the ISR for every falling edge, and every ~2us afterwards. 1k...

73 views
Amiga Floppy

Am I reading MFM wrong?

I’m beginning to think that I don’t fully understand the signalling coming out of the drive. I understand the concepts behind MFM (I think), but the actual application to this project, I’m not so sure...

73 views
Amiga Floppy

AFP 0.2 WIP SX code

I’ve put some work into cleaning up the SX code tonight. I’ve removed some code sections no longer needed, and added documentation where it was lacking. Code should be commented pretty good. I’ve also...

72 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...

71 views
Amiga Floppy

proof of concept works

Today is the first day in months that I’ve made what I consider good progress. I am now able to read any track(so far) off of any disk with 100% success including checking and relying on the checksums. I read...

71 views
Amiga Floppy

March 21st Status

Well, here’s where I’m at: The external amiga floppy drive is now hooked directly to my SX microcontroller.  The code within the microcontroller waits for a command.  If it get’s a “B”...

70 views
Amiga Floppy

good data vs bad

So you’ve seen me talk about good data and bad data.  But what’s the difference? Good data looks like the picture I posted awhile back here. Note the very even spread of 4—4—8.  Every pattern is...

70 views