🚀 go-pugleaf

I have been unable to get a Xylogics XY 753 to work properly with a CDC
XMD-II (9772) 850 drive.  It appears as though they are not agreeing on
how to access the extended cylinders (> 1023). The manual on the XY 753
states that it ONLY supports the SMD-E spare line (tag 4) as providing the
10'th cylinder address bit. However no matter what switches I set on the
drive (SMD-E mode, Extended addressing), it always seems like the 10'th
bit is getting ignored, in other words, it is OK if formatted to 1024
cylinders, (the drive as 1064), but as soon as I format the extended
cylinders, it formats over cylinders 0 thru 39 causing problems since the
cylinder headers are now wrong.

I tried it with two different XY 753 controllers, two different sets of
cables, two different drives. The same drive works fine with a Rimfire
3200 controller.  The XY 753 works fine with CDC Sabre drives (9720-850
and 1230).

Anybody done this before?

BTW, this is on a 3/260, but I don't think that makes a difference since I
also tried it on a 4/370. Here is my format.dat entry, but I think the
problem is hardware, not software.

disk_type = "CDC XMD-II 9772 (850)" \
	: ctlr = XD7053 \
	: ncyl = 1062 : acyl = 2 : pcyl = 1064 : nhead = 16 : nsect = 82 \
	: rpm = 3600 : bpt = 50400 : bps = 606

Thanks for any suggestions.

Russ Poffenberger               DOMAIN: poffen@sj.ate.slb.com
Schlumberger Technologies       UUCP:   {uunet,decwrl,amdahl}!sjsca4!poffen
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