pc/devata.c		1995/0213		Created.
		1995/0214		BUG fix/clarity fix?: explicitly name reglock so that ilock can be explicitly told to use the lock, not the qlock. XXX check compiler
		1995/0215		disable debugging prints
		1995/0222		disable debugging prints
		1995/0726		anonymize
		1995/0728		HW BUG double fix: empty buffer always; also set cp->buf even though we don't need to in ataprobe. (Either would fix the HW bug).
		1995/0818		deanonymize atacreate (XXX).
		1995/0908		HW bug fix: probe for fewer heads, sectors per track.
		1995/1206
		1995/1208
		1995/1209
		1995/1218
		1995/1219
		1995/1221
		1996/0112
		1996/0210
		1996/0215
		1996/0216
		1996/0223
		1996/0315
		1996/0803
		1996/1225
		1997/0327
		1997/0408
		1997/0812
		1997/0815
		1997/0818
		1997/1230
		1998/0106
		1998/0115
		1998/0219
		1998/0319		Change dev read and write to use vlong offset.
		1998/0327
		1998/0331
		1998/0501
		1998/0510
		1998/0516
		1998/0825		Bug fix: print format.
		1998/0831
		1998/0910		Change VectorPIC+isa.irq to isa.irq.
		1998/0922
		1998/1006
		1998/1007
		1998/1101
		1998/1126
		1999/0324
		1999/0714		Use ioalloc.
		1999/0819
		1999/1230
		2000/0308
		2000/0517		Deleted.