View Single Post
Old 25 May 2019, 11:12   #49
Toni Wilen
WinUAE developer
 
Join Date: Aug 2001
Location: Hämeenlinna/Finland
Age: 45
Posts: 24,638
Quote:
Originally Posted by ross View Post
So with some well crafted code and an untouched real blank floppy you can theoretically replicate some impossible to copy "weak bits" protection.
I don't think it works with DMACON because I am quite sure RW head is still being driven (floppy write gate signal is active). I assume it is bit 14 that controls it + DSKLEN being in "active" state.

But I guess you could stop writing temporarily by clearing bit 14 of DSKLEN (but keeping bit 15 set), if bit 15 is kept set, new DSKLEN value gets loaded in internal disk length counter without interrupting active disk DMA. EDIT: But switching read<>write on the fly probably causes other side-effects because afaik read and write uses different Paula internal fifo logic.
Toni Wilen is offline  
 
Page generated in 0.07745 seconds with 11 queries