.sh TAPES We use Emulex TC-11/P UNIBUS tape controllers and Kennedy model 9300-3 800/1600 BPI 125 IPS transports. Cipher tape drives and Wesperco controllers are also widely used. When purchasing second vendor equipment, one will also need cables and a rack in which to mount the tape drive. The Kennedy transport comes with a 15 month factory warranty. Our distributor exchanges/repairs the cards in the controllers based on a local diagnostic mode in the transport. After the warranty period, card swaps cost about $75. For transport mechanical failures the transport is returned to the factory in Monrovia, California, or we fix it ourselves. .LP George Goble at Purdue is using a 6250 tape system with UNIX. It includes a Telex 6253 drive (800/1600/6250 BPI) 125 IPS with a TELEX Formatter and an Aviv 1 board UNIBUS interface. The UNIBUS interface has 4KB of buffering, to help with bus latency problems, and it really appears to be necessary. The whole system cost him about three times what our 1600 bpi systems cost. The Aviv controller emulates a TU10 which is similar to the Emulex NRZ/PE controller. When heavy data transfer is done to the drive at 6250 bpi it uses the entire bandwidth of the UBA. This forces UNIBUS access through the UBA to be arbitrated by the operating system in order that the tape drive and a disk controller may coexist on the same UBA. \fBN.B.\fP: The driver for this controller/transport combination is not currently included in the standard 4BSD system but is trivially cloned from the TM11 handler which is a standard part of the distribution. Aviv also has a TM-11 compatible controller, the TFC 822, which supports both Kennedy and Cipher transports. This controller has more internal buffering than the Emulex TM-11 emulator and may be preferable for this reason. .DS .TS l l l. Name Speed Densities _ Kennedy 125ips 800/1600 Telex 125ips 800/1600/6250 .TE .DE .LP Our original VAX system came in a package with a DEC TE16 on its own MBA. The TE16 is reliable but slow. The DEC TU45 is faster, but fraught with problems as the high maintenance cost reflects. The DEC TU77 is a good transport, but the auto-loading features do not seem to work well, and it is expensive. Finally, there is a relatively new product from DEC, a 1600/6250bpi 125ips tape drive, the TU78. This is the same transport as the TU77. We have two TU78s in use on campus with mixed results. .LP The UNIBUS tape drive, the TS11, is included in packages for the 11/750 except for the RK07 package system. It does not have a vacuum column, and is thus hard on tapes. It is a problem to load and has been found to be unreliable. .DS .TS l r l l. Name Speed Densities _ TS11 45ips 1600 (Not recommended) TE16 45ips 800/1600 TU45 75ips 800/1600 (Not recommended) TU77 125ips 800/1600 TU78 125ips 1600/6250 .TE .DE