The theoretical limit, assuming 300rpm drives, is 200ms per track. Or 400ms per cylinder, or 32 seconds per disk. Most attempts read slightly more than one track. I read 16,384 bytes, or 262ms worth. Right now, if I...
Archive - January 2007
Good news good news. First perfect .adf
Good news indeed! I’ve managed to create a fully functioning .ADF from a floppy. I matched the output from my hardware/software combination with a “transdisk” output, and it matches exactly. I used...
working cause of bit errors
I think I’ve stumbled on something. I don’t think I’m capturing enough data. 13,824 has been my magic number forever. It was larger than the 13,800 that Marco used in afr.c. But I’m beginning...
first .adf written
Well, I’ve written my first .adf tonight! I threw together a quick routine on the PC side to query the SX for both sides and all the tracks. It generated a 901,120 byte .ADF file of a disk I had called...
sync’ing to the 0x4489 0x4489
Well, this wasn’t as easy as I first imagined. There are some issues: 1> By the time you’ve detected the 4489 4489, it’s too late to do much about it. This is because I’m writing one bit at a...
new isr thoughts
While this new ISR is indeed easier to understand and much more simple, I can’t help but remember what else my ISR used to do for me. The four things I really lose are: 1> Any type of double 1’s protection...
Anatomy of a flux transition
I wanted to put up an image that displays an actual flux transition pulse coming off an amiga floppy disk whose data was encoded in MFM.
CLICK ON THE IMAGE TO DISPLAY A FULL RES VERSION.
Timeline
I’ve put together a time line of events starting from November 2004, the initial idea.
CLICK THE ABOVE IMAGE FOR A FULL SIZE VERSION.
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...
Logicport screenshots and project file
I thought this might be neat to put up. Sorry about the high-res image but you lose too much when it compresses it. Click here for the screenshot. Also, I uploaded the .LPF project file which can be viewed for free with...
