CDC 9720-850 disk drives with VAX 4.3 BSD ??

[Mark Plotnick]

Here are our changes:

struct	size {
	...
}, rm05_9720_sizes[8] = {
	40800,	0,		/* A=cyl 0 thru 39 */
	142800,	40,		/* B=cyl 40 thru 179 */
	1408620, 0,		/* C=cyl 0 thru 1380 - whole disk inc bbt */
	1224000, 180,		/* D=cyl 180 thru 1379 - end of swap to bbc */
	408000,	180,		/* E=cyl 180 thru 579 - 1/3 */
	408000,	580,		/* F=cyl 580 thru 979 - 2/3 */
	816000,	580,		/* G=cyl 580 thru 1379 - 2-3/3 */
	408000,	980,		/* H=cyl 980 thru 1379 - 3/3 */
};
struct hpst {
	...
} hpst[] = {
    ...
    { 68, 15,	68*15,	1381,	rm05_9720_sizes,15,8, 3, "9720" },
};

We've had 1 9720 on its own SC7003 (Emulex recommended not putting
non-9720 drives on the same controller with it) on an 8650 for a month with no
problems.  In January we plan to chain on 3 more.

Incidentally, the vanilla 4.3 driver mishandles ecc errors with some SI and
Emulex controllers [was this driver originally written just for
an RH?].  Rick Adams (of CSS) and Jim McKie (then of Bellcore) have
graciously been passing around some modified drivers, which work better.
Rick's also allows on-line formatting, but during formatting the driver
sometimes reports ecc errors in sectors that are off by 1.  If anyone has
corrected bugs in any of these drivers, please send them along.

	Mark Plotnick
	allegra!mp