TU80 Problems.(VAX780)

[Marc Vauclair]

<For the line eater, if any.>

Sometimes our TU80 tape drive get lost, i.e. any command to the tape
(dd, tar, mt, ...) is blocked and the corresponding process is unkillable.
Till now, the only cure we know to recover from that is to shutdown the
machine and to reboot (a very unpleasant cure indeed !).

	We observe that the following error messages are reported on the
console (and in /usr/adm/messages) some time before the TU80 disappears : 

	Oct 28 10:50
	uba0: too many zero vectors
	uba0: reset dz0 dz1 dz2 dz3 uda0 ts0.

Here is our configuration as reported in /usr/adm/messages :

	4.2 BSD UNIX #3: Fri Jan 25 17:20:47 MET 1985
	real mem  = 6287360
	avail mem = 5133312
	using 307 buffers containing 628736 bytes of memory
	mcr0 (el) at tr1
	mcr1 (eu) at tr1
	uba0 at tr3
	uda0 at uba0 csr 172150 vec 774, ipl 15
	ra0 at uda0 slave 0
	ra0: RA81
	ra1 at uda0 slave 1
	ra1: RA81
	zs0 at uba0 csr 172520 vec 224, ipl 15
	ts0 at zs0 slave 0				<TU80>
	dz0 at uba0 csr 160100 vec 300, ipl 15		<DZ-11>
	dz1 at uba0 csr 160110 vec 310, ipl 15		<DZ-11>
	dz2 at uba0 csr 160120 vec 320, ipl 15		<DZ-11>
	dz3 at uba0 csr 160130 vec 330, ipl 15		<DZ-11>
	vp reset vec from 200 to 174
	vp0 at uba0 csr 177510 vec 174, ipl 14		<VERSATEC>

	Did anyone expercience such a problem ? Does anyone know a cure
to it ?  Please answer by mail.

		Thanks in advance,

			Marc Vauclair
			Philips Research Laboratory Brussels

			mvauclair at prlb2.UUCP