SUMMARY: Connect tape HP88780B to 4/110

From: Joao Neves (
Date: Wed Jan 08 1992 - 16:26:15 CST

The original posting was:

>Hi I'm having some problems connecting a 1/2" GCR tape, with SCSI interface
>to a Sun 4/110. I'm quite shure that the SCSI cable is correct.
>Every time I connect the tape to the SCSI the system hangs or doesn't boot
>(can't find the boot disk)
>BTW I don't have the tape manual :-(, certainly I'm missing something.
>Any help is welcome :-)
> - Sun 4/110, with 32M RAM, running SunOS 4.0.3
> - 2 disks Micropolis 1558
> - 2 disks Seagate ST41200NSL
> - 1 1/4" tape QIC-24
> - "called" Sequent
> - SCSI diferencial (?) interface
> - model HP88780B, 1/2" GCR

The solution is:

I can't connect the tape with this kind of interface to Sun SCSI.
I'll try to get a compatible one (any sugestions to find it? :-))

I selected two messages that "best" describe the problem and the answer.


From: trdlnk!mike

>> - "called" Sequent
>I don't know what you mean by this.

JN: That is the label that it's on the front panel

>> - SCSI diferencial (?) interface
>I presume you mean "differential." If this is the case, it is a

JN: You're right. After all portuguese isn't so difficult :-)

>big problem because Sun SCSI ports are single-ended (the opposite of
>differential) and it is not possible to interconnect single-ended and
>differential devices.
>> - model HP88780B, 1/2" GCR
>If the problem is not a differential interface, check that the SCSI cable
>is terminated properly (if the HP tape drive is at the end of the SCSI
>cable, you need to plug a terminator into its empty SCSI connector).

JN: Follows some useful information for tape operation, mainly if you
    haven't the manual :-)


From: Steve Hanson <>

You're going to have a REAL hard time getting this to connect. If the tape
drive is differential SCSI, you can't connect it to the 4/110, which is single-
ended. You can't have the "correct" cable because the interfaces are incompati

I believe there are converters available, but I'd tend to have doubts that
you're going to get this to work. You're also probably going to
have to do some playing with the SCSI tape driver to get it to recognize the
drive as a 1/2" device.


Thanx also to:

Margaret Mikulska <mikulska@ece.UCSD.EDU>
Kevin Sheehan <kalli!kevin@fourx.Aus.Sun.COM>
David Fetrow <>
Barry Shein <>

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