The issue was with a STE machine, which was continuously
or intermittently reporting the floppy was write protected when it was
not.
The assumptions are the drive has been tested and working fine in another machine. It is also assumed that the WP pin on the 1772 is always high (for write enabled operations), Or indded switching as it should.
The fix for this issue to solder a 10K bussed resistor array to the 1772 databus pins as illustrated below.
The white wire connects the common pin on the resistor array to 5V.
The investigation into this fix can be seen on my forum.
https://www.exxoshost.co.uk/forum/viewtopic.php?f=23&t=1410
This fix may likely fix a lot of DMA hard drive issues. More DMA research here
http://www.exxoshost.co.uk/atari/last/DMAfix/index.htm