Libra 8 DDS3 Tape Changer Teardown

Teardown of the Libra 8-DDS3 SCSI tape changer dated 1999. It has been standing around in my basement for about 10 years now and I'm going to disassemble it and make some other use of it to get rid of that large hunk of metal.
Music by www.LukHash.com
Video License: CC BY-SA 3.0

[@johndoe271828]

Ah! Should've looked that up. Sometimes I forget the dark ages in which pretty much every peripheral (reset, WDR, RAM, ROM, GPIO) was external. I also found the design pretty interesting, glad that you liked it.

[@ChipGuy]

Cool Video :) The TL7702 is the RESET generator for the Zilog µP. My guess is that the two resistors next to it are the voltage devider to make it work for either 5V or 12V. There is also a TL7705 for 5V available so you dont need a resistor. They must have a reason to use the 2V version with an extra divider. Still interesting that they use 3 microprocessors/microcontroller design to make that thing work.

[@SeanBZA]

Standard power supply, and you missed that it has 2 LUN numbers, one for the DAT drive ( what size tapes does it use) and another for the control interface. Control IF receives a serial data stream to get info about tapes and status, and sends data to select a tape for load/unload. Basic error detection in there as well to detect stuck tapes and to give mechanism position indications. Better than sitting around to change tapes, and the joy of spanning across multiple tapes and having an error.

[@johndoe271828]

Yes, you are correct. It's been too long since I've had the unit in productive use so I didn't remember the details. During disassembly I though they might share a LUN (and one device ignores the commands for its respective other). Yup, there's error detection with the light barriers (two forked barriers and three pairs of SFH480-2/BPY62-4 in TO-18). Haha I remember the joy of changing tapes. Horrible. The good old time is now! ;-)

[@ensigner5619]

Hi johndoe271828, You sound like German, I hope? Mein Englisch ist sehr schlecht. Vielleicht habe ich Glück und Sie verstehen mich? Ich habe ein Problem und vielleicht wissen Sie Rat. Ich habe mehrere gebrauchte DDS-2 und DDS-3 Kassetten aber schon lange keinen Drive mehr. Habe vergeblich online nach einem passenden external Drive gesucht der Mac-compatibel ist (für iMac oder MacMini oder G4 Powerbook. Gibt es keine solchen Drives? Wie kann ich sonst Zugang zu den Daten auf diesen Tapes bekommen?