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

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...

79 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...

79 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...

78 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...

77 views
A501 Replacement

Let the fun begin!@#!@#

 
Everything has arrived!  I think the first order of business is soldering this darn memory chip…. Not sure how hard this is going to be, but I’m going to give it a shot!@#

77 views
Amiga Floppy

feasability of writing disks

While there are some other bug fixes and documentation to be done on what’s already been implemented, I started thinking about writing ADF’s to disk over the last few days. While the hardware part of it is...

76 views
Amiga Floppy

new design

I took David’s advice, and I rewrote the code last night. Some highlights: 1. ISR is entirely in assembly. Although I haven’t manually counted, it appears to be about 400ns in length. 2. ISR triggers only...

76 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...

76 views
Amiga Floppy

more success reading valid data!

I created a disk with a textfile called AMIGA on it which contained thousands of “AMIGAAMIGAAMIGA” throughout the entire file. The idea here is that no matter which part I happen to read/decode, I can tell...

75 views