Many years ago, a friend gave me an Overland T490 tape drive which has some kind of autoloader attached which takes ten tapes. I was told it came out of a Tandem system. The tapes are square cartridges similar but different to a DEC TK50. I can't find very much information about the drive on the web but there are some hints that it might be compatible with an IBM 3480. It powers up nicely and the fan works and after a short pause, a green LED illuminates. There are only two buttons on the front, "unload" and "format".
There are two DD50 connectors on the back. One had a terminator plugged into it labelled "SCSI differential". The other had a ridiculously long cable with DD50 plugs on it connected, lending further credence that this is a differential (pre-LVD I expect) SCSI device. I would like to get this drive working with my Alpha or VAX VMS systems but I have never had any luck getting them to talk to it. Recently, I tried a using a DD50-HD68 cable I found somewhere to connect it to a differential SCSI card in my Alphaserver 800 but I could not get VMS to see the drive. Not knowing what SCSI id the drive is likely to be using makes it hard to know where to start looking for it. There are no switches on the outside of the drive which could be used to set the SCSI id so I opened it up to see if I could find any hints inside. I didn't see anything that looked like it could be used to set the SCSI id inside either. What I did find is that the interface board had a connector labelled "SCSI differential" which had two short lengths of ribbon cables plugged into it leading to the two DD50 connectors on the rear panel and another connector labelled "SCSI single ended" with nothing attached. There were also two ten way jumper packs which were labelled "DI" and "SE" on each side. So, not having any luck with differential so far, I tried moving the two jumper packs from "DI" to "SE" and moving the ribbon cable to the "SCSI single ended" socket. I used a short, known good DD50-DD50 SCSI cable to connect the drive to my VAX 4000-100A and replaced the differential terminator with a known good single-ended terminator. VMS didn't see the drive. VMS has a utility called scsi_info which can be used to send a SCSI inquiry command and read mode pages etc. Trying it against each unused SCSI id results in "device timeout" every time. The system disk is on the same SCSI bus before the tape drive and a SCSI scanner can be connected after it on the bus. Both devices work fine so the SCSI bus cabling and termination is in good shape on both sides of the tape drive. I've tried moving the system disk SCSI id from 0 to 1, changing the initiator SCSI id from 6 to 7 and replacing the scanner with a terminator in case there is any sort of SCSI id conflict but scsi_info still doesn't show up anything that could be the tape drive. Does anyone have any information about this drive, particularly whether it should behave like a standard SCSI tape drive and what SCSI id and/or lun it is expected to use or if there is some trick required to get it to start talking? Maybe it doesn't like SCSI inquiry commands? Extra bonus points awarded for details on how to control the autoloader. Maybe I did some damage to it when I was trying to get it to work when I first got it? Regards, Peter Coghlan.
