Interpretation wanted for HDERR code EF:1

[m.yamin]

Does anyone know what HDERR error flag 1 means?  Here is a specimen
line from unix.log:

HDERR ST:51 EF:1 CL:4282 CH:4200 SN:4208 SC:4202 SDH:4224 DMACNT:FFFF
DCRREG:94 MCRREG:8900 Tue Sep 19 20:58:09 1989

The disk is a new Seagate 251-1 controlled by the original WD1010.

gdisk.h offers some interpretation of the status and error codes thus:
/*
 *	Status information for WD1010.
 */
#define W_ERR		0x0001	/* logical or of bits in the error register */
#define W_CIP		0x0002	/* 1= command in progress */
#define W_DRQ		0x0008	/* 1= data request outstanding */
#define W_SEKCMP	0x0010	/* 1= seek complete */
#define W_WRFLT		0x0020	/* 1= write fault */
#define W_RDY		0x0040	/* 1= ready,frozen on error until status read */
#define W_BUSY		0x0080	/* 1= WD1010 is accessing the disk */
/*
 *	Error status information for the WD1010.
 */
#define W_BBD		0x0080	/* bad block detected (not used) */
#define W_CRC		0x0040	/* 1= CRC error */
#define W_ID		0x0010	/* 1= id not found */
#define W_ABC		0x0004	/* 1= aborted command */
#define W_TK		0x0002	/* 1= restore command did not find track zero */

So ST:51 means seek is complete, the register is frozen until the status
is collected, and there is a bit set in the error register.  EF:1, I suppose,
means that's what's in the error register, but no interpretation is given
for this bit (0x0001).  Some days I get hosts of these, other days nary
a one; it seems to depend on what mood the disk woke up in.  (For example,
yesterday I got enough so that unix.log cleared itself several times,
and since booting today I haven't seen a single error, and I haven't touched
the machine).  The "errors" do not affect the operation or performance of
the system in any way, do not result in wrong data, and do not result in
audible re-seeks or recalibrations as EF:40's and EF:10's do; I know what
those sound like, because I heard plenty of them on my old Miniscribe.
EF:1 is the only error flag I've seen on this disk.

					M. Yamin
					myamin at cbnewsm.ATT.COM