0661-371 320 MB, 3.5x1.6, 4317.8 RPM
0661-467 400 MB, 3.5x1.6, 4316 RPM
1.05 GB, 3.5x1, ???? RPM
0664-x1H 2.0 GB, 3.5x1.6, 5400 RPM
DSAS-3720720 MB, 3.5x1, 4500 RPM
160MB, 3.5x1, 3600 RPM ???
Hi Charles !
>Could you elaborate or point to a reference on this aspect of HDD
I sure can. The 0661 / 0662 / 0664 drives are 1st generation Magneto-Resistive Head drives and the platter cage (the black case inside the drive assembly) has to be ground-free not to interfere the signals under the heads. The heads are driven via a differential driver and grounding the platter-cage would disable the heads from reading any information. At least one of the fixing holes is a bit oddly positioned and a fixing screw longer than 5mm would be one or two threads too long and touch the platter cage, cut through the black paint onto the metallic cage ... and ground it.
Result: the drive will not come up ready, make "marble bouncing sounds" since the lower "servo" head cannot read the tracking informations - and after some time the drive drops the platter motor and a SCSI error code appears.
When you look closer at the drive you will find large black plastic
>Anyways. Maybe it's not that complicated. Why should IBM's
They aren't. But IBM is a professional company and has a good public image on reliability. Sometimes caused by the additional care they put in efforts of proper grounding and avoiding electronic interferences where possible - try to get rid of problems right from the start. The additional grounding *can* be ignored - drives will run fine without that ... but in very, very worse cases it might give additional security.
>Do us users just screw this up accidentally all the time?
Users are the computers only natural enemies. They are able to louse up even "fool proof" constructions.
>I've no idea of how worried I should be about this. A real problem,
The above-mentioned drives need some caution and care - the later ones
are mainly uncritical. With the introduction of the DSAS and DPES series
IBM returned to other conceptions of the R/W-amplifiers and different screening
of the drive. These are rock-solid general purpose drives, which need no
Don't forget that the 0661-design is almost 8 or 9 years old. IBM was
My 9595-AMF for example still has the 400MB 0661, P/N 73F8958, FRU 82F0012 it came with. Drive is made by IBM (UK), EC 894769.
Compared to other drives it has:
Still going strong after some billion rounds :-)
Can't find it here? Go to the source- IBM Hard Disk Drives
Sometimes IBM doesn't have it either, so go to The Ref
Please email with your IBM Drive type and I'll dig it up and post it...