case: d :
	case: d : dd <phy_drv#> [<sector>] - Dump secrtor
	case: i : di <phy_drv#> - Initialize disk
	case: s : ds <phy_drv#> - Show disk status
case: b :
	case: d : bd <addr> - Dump R/W buffer
	case: e : be <addr> [<data>] ... - Edit R/W buffer
	case: r : br <phy_drv#> <sector> [<n>] - Read disk into R/W buffer
	case: w : bw <phy_drv#> <sector> [<n>] - Write R/W buffer into disk
	case: f : bf <n> - Fill working buffer
case: f :
	case: i : fi <log drv#> - Initialize logical drive
	case: s : fs [<path>] - Show logical drive status
	case: l : fl [<path>] - Directory listing
	case: o : fo <mode> <name> - Open a file
	case: c : fc - Close a file
	case: e : fe - Seek file pointer
	case: r : fr <len> - read file
	case: d : fd <len> - read and dump file from current fp
	case: w : fw <len> <val> - write file
	case: v : fv - Truncate file
	case: n : fn <old_name> <new_name> - Change file/dir name
	case: u : fu <name> - Unlink a file or dir
	case: k : fk <name> - Create a directory
	case: a : fa <atrr> <mask> <name> - Change file/dir attribute
	case: t : ft <year> <month> <day> <hour> <min> <sec> <name>
	case: x : /* fx <src_name> <dst_name> - Copy file
	case: m : fm <logi drv#> <part type> <bytes/clust> - Create file system
	case: t : t [<year> <mon> <mday> <hour> <min> <sec>]