I keep hearing about this Catweasel board and I've never read of anyone successfully using one. My be if it works there may be nothing to tell. NS* floppies are a simple affair. The logic needed to read them is trivial and the data rate is 15625(SD) or 31250(DD) bytes/second. The NS* board logic is clock recovery, shift register and a 8wide NAND to detect if the pattern in register is a sync byte. The basic read is, wait for sector hole (hard sector has both an index hole and a data sector hole and a oneshot is used to tell which is which. Once the desired sector hole is found wait for sync (FBh). When sync is found read bytes as they are data(256 sd or 512 dd) the next byte is a check char if the check matches data in ram check byte you have a sector. There are no bytes for sector address or other info as hard sectoring us used to track that. In 8080 code ignoring the head step and all the other housekeeping the read sector code is less than 50 bytes. You can find that code on the net (NS* BOOT ROM). Because of it's simplicity I'm surprized no one has implemented a PC parallel port interface that is a subset of the NS* MDS sans boot roms and bus interface as the data rates are not out of the realm of what a 386 class or faster PC can transfer from a printer port. Manual and prints for the S100 card are available on line and the manual has low level programming information as well. There are no mysteries either hardware or software and the design is dirt simple. Actual parts count for the MDS=A (SD version ) is 47 peices TTL and if you take out boot proms (2 256x4 74287) and board select prom (1 256x4 74287) and the parts needed to talk to the S100 bus your under 40pieces of TTL the most complex of which is 74161 (4 bit counter). I'd add the SD version does not have any analog (opamps) or RC oneshots though the DD version does. the basic timing of the board is a long string of counters synced to the index hole to provide sector position (R/W) and byte timing for (W) and motor time out. No state machines or anything fancy. Allison