> 2: explain the struct of FDCtrl; In order to know what those fields in FDCtrl mean, you might need to read ftp://download.intel.com/design/archives/periphrl/docs/29047504.pdf first. As the comment in hw/fdc.c says, it's Intel 82078 floppy disk controller emulation.
Regards, chenwj -- Wei-Ren Chen (陳韋任) Computer Systems Lab, Institute of Information Science, Academia Sinica, Taiwan (R.O.C.) Tel:886-2-2788-3799 #1667 Homepage: http://people.cs.nctu.edu.tw/~chenwj