keith
OK Great news. As I stumbled on in the last post: I’ve fixed my reading issues, and I’m now reliably reading, in one shot, an entire amiga track from the unmodified standard PC drive!! When seeing double...
current read problems
It seems as though when I have a read problem, its normally minor, and is a single bit error. I notice that the errors have a tendency for 0s to be incorrectly interpreted as 1s. So I get AB instead of 2B, AB instead of...
interesting results
OK, I’ve applied the “double 1’s” fix that I talked about earlier today. This definitely helped things. I think my results are quite possibly the best I’ve seen them yet. Now, my SX...
SX problem is double-ones, ISR code & description
While I shouldn’t be surprised, my SX hardware issue is related to double one’s, where the SX sees transitions back to back, and writes back to back 1’s into memory. This is assuming there aren’t...
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...
MFMSanityCheck
While I’m hesitant to post this at all, this is a quick and dirty application I threw together, and I do mean threw, that will check for valid MFM bytes. See the previous post for the link to the actual bytes. It...
example files
I wanted to put up some example files. Note that a preceding “D” for dump and two delimiting 0xFF’s might exist in these files. Also an ending 0xFF 0xFF might exist. So two bad files below have exactly...
recent status
Well, I’ve put a decent number of hours in on the project over the last couple weeks. I’ve mostly been “spinning my wheels” because I haven’t made much progress, but I think I’ve...
looking at the code this a.m.
Welp, I decided to take a look at my code today, although I can’t actually implement anything until after I get home from work. 🙂 Not sure if I mentioned this eariler, but I’m now padding the data sent from...
Found another UART timing issue
Ok. A post or two back, I mentioned that I wanted to rework the receive UART because it wasn’t working perfect. I fixed that, and now it’s reliably receiving. I also mentioned that my sending uart code was...
good data vs bad
So you’ve seen me talk about good data and bad data. But what’s the difference? Good data looks like the picture I posted awhile back here. Note the very even spread of 4—4—8. Every pattern is...
slacking indeed
I’ve been horrible about the project lately. Dunno why. Today is the first time I’ve looked at it in quite some time. The last couple hours have been spent trying to remember exactly where I’ve been...
new pictures
As you can see above, we have a “10” (4 us), another “10”(4 us) and a “1000”(8 us) chunks of data. Little noisy there.
minor success at 2:00am
well I’ve got MFM flowing from the PC drive now. A couple of things: Pins 10 and 14, the pins I’ve been using since last night, appear to be correct. Pin 10 is the motor lead. Dropping a corresponding SX...
going around the problem
Welp, I’ve ordered a new, but cheap ($5.99!) regular PC floppy drive from newegg.com. I like this end result much better anyways. PC drives are much more available, popular, cheap, and so on. was worried about...
more testing
so I put the amiga floppy back on the amiga, and the amiga reads disks no problem. Glad to see that my drive hadn’t fried through all my messing around. I haven’t seen valid MFM coming from the drive in so...
still giving me trouble
I spent some time on the project last night. Still no-go. The SX and the software is behaving as expected by responding to commands, transferring the buffer, so and so forth. I’m getting garbage data from the...
cleaned up the project
So after banging my head for awhile, things still aren’t working as they had prior to my stepping away from it. What I did last night was to partially dissassemble everything, and rewire a decent portion of it. ...
