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

even first or odd?

Despite having a couple different official sources, both AFR.c and floppy.c from the fellow amiga emulator says that the even bits come before the odd bits. This is true in the sector header decoding as well as in the...

added version control and another command

I’ve really wanted version control for a long time.  The ability to go back and undo diverse changes across sessions is valuable.  I also feel a little safer and don’t mind doing semi-destructive edits...

memory chip mounted

Welp, I got impatient, and went to Radio Shack to buy their soldering station. I still have mine coming in the mail, but its ground from Arizona, which may as well be ground from Alaska. I soldered the header pins onto...

Success!@#

I hestitate to jump to conclusions, but I think I just passed a crucial first step in getting this to work!@#!# After adjusting some timing on my new code on the SX, I’ve found my first 0x4489 0x4489 pattern. This...

adding more commands

Now that I *think* I’ve got a handle on the reading portion, I’ve been adding a couple more commands. I added support so that the SX knows what cylinder number it is on.  The F and B commands increase and...

revisited memory routines

I was looking over my reading and writing routines. Minimums for the fram are Clock high min. 28ns Clock low min. 28ns Data setup min 5ns I write in two places: First, when bits are coming in from the drive, and the ISR...

will put up sample files

I’m going to put up a sample file or two, but I wanted to get the smallest complete group of bytes that I can…. ie like one full sector, etc. So far, I’m just basically streaming bytes, via disk copy...

writing merged USB comm code

Now that I have USB receive working in the main PC code, its time to merge the USB transmit(and receive for commands) into the main SX code. I have two pseudo-code versions written. 1> First version uses the ISR to...

java client preview

I’ve put up a preview of the java client in action. It’s a 2 minute video with narration. You’ll need a DivX codec installed in order to view it. I probably could have messed with compressing this...

more SX to PC tests

Although I think I’ve long had this working good, I did some more tests just to verify. Latest numbers: Each cycle is about 15.8us, 2us per bit, 8 bits, this sounds fine. This does confirm, however, what I...