techtravels.org

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...

Latest articles

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...

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...

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...

losing data

I’ve been thinking more and more about how exactly I’ve been losing data. It’s alot of data. The worst case I’ve seen is about 140 bytes. This is 1120 bits, or 2240us. This is a LONG time for my...

Finally had some luck with FPGA board

So I bought an FPGA eval board and a book on Verilog awhile back.  I made some progress learning things, and had some simple things like UARTs, writing to the LCD, and even some small VGA software(hrrrm, maybe I should...

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...

simplified ISR

It looks as if I spoke too soon. I’m still having reading problems.  The data used to be forced into an MFM mold, but all that’s done in some cases, is to further corrupt the corrupt data. I rewrote my ISR...

amiga floppy project activity

I don’t know how interesting this is, but I thought I’d throw it up anyways. I exported the posts and comments tables from the mysql database, imported into Excel, and then created an activity graph of the...