Ok, I’ll admit it. I’ve been slacking like the best of them.
I’m not horribly unsatisified with my progress, especially this year. The first four months of this year I achieved the following:
* Data is now byte-sync’d, transferred sectors in order Februrary 17th
* Working Java client March 26th
As far as next steps go, I’ve got to
1> get error correction and retries working in the java client
2> clean up the gui and set up a “save config file” option, selecting serial ports, etc
3> clean up the java code
4> start testing it under Ubuntu
I’m very interested in error recovery, and I have been putting a decent amount of thought into it. I’m really fascinated by the fact that Amiga floppy disks have tons and tons of structure. First, the MFM is output in such a precise and predictable way, ie we know that no two 1’s are found back to back, no more than three consecutive zeros, etc. We also know about the way clock bits are inserted. And because of this fact, only certain bytes are possible when made up of these certain bit patterns. In fact, only 32 are possible. With the help of a checksum, I think it would be possible to brute-force a certain number of bad bytes. Now I do think that the checksum is particularly unhelpful for this (XOR, I think), something like MD5 would be da bomb. No false chance of duplicates yielding the same checksum. I don’t understand or appreciate the (math-based) ramifications of using XOR though. It’s certainly used everyplace within encryption, so this is might be better than I think.
My read routines are no longer raw, although I’m probably going to go back and add a raw read function.
I’ve tossed around the idea of simplifying this project even further by eliminating the FRAM memory and adding real-time functionality which I know the emulator crowd wants. This is further down the line, and honestly, I don’t even know if its possible (or at least, not sure how I would do it)
I’ve still been managing between 12,000 and 20,000 hits per month (about 10,000 unique visitors), and so I really appreciate the continued interest people have shown. This is really a fun project, and I’m looking forward to expanding it and making it better and more useful.