These are all 2us per division on the scope. Top trace is the actual MFM, bottom trace is the entering and exiting of my ISR. You should see an entry into the ISR for every falling edge, and every ~2us afterwards. 1k...
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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...
Samsung SFD-321B 3.5″ floppy drive and specifications
I plan to create a separate section for these type of documents, but I wanted to get this online for now. I purchased the Samsung (made by SEMA, the division split off of Samsung that mostly makes floppy drives) SFD...
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...
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...
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...
