Path: utzoo!attcan!uunet!ginosko!gem.mps.ohio-state.edu!tut.cis.ohio-state.edu!ucbvax!pro-graphics.cts.com!bobl From: bobl@pro-graphics.cts.com (System Administrator) Newsgroups: comp.sys.apple Subject: Vanilla SCSI Tape Drive Construction Message-ID: <8908290234.AA02391@trout.nosc.mil> Date: 26 Aug 89 19:17:57 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 127 Build Your Own Vanilla SCSI Tape Backup System by Dr. Kenneth Buchholz Box 430 RD#4, Washington NJ 07882 Copyright 1989 ________________________________________________________________________ Make Mine Vanilla (Introduction) Last autumn, I assembled my own "vanilla" SCSI hard drive subsystem using the Seagate ST277N drive, the Tulin AppleHive case, and CMS SCSI Interface Card and saved about $250 by "building my own". Since my first online article on the assembly appeared last year, thousands of others have followed suit and assembled their own SCSI hard drive, and the popularity of these homebrew hard drives is illustrated by the wealth of online and magazine articles which have followed. During the following months of helping others assemble their own hard drive, giving tutorial presentations before Apple user groups where members would assemble their own hard drive during the presentation, and writing follow-up articles for online services, my own BBS, magazines and newsletters, it became quite apparent to me that what we all needed next was an inexpensive SCSI tape backup system. Acquiring and assembling the hardware was the easiest part - find the software needed to format, backup and restore was the difficult part since Apple, nor anyone else, has released either drivers for a SCSI tape system or tape backup software. Fortunately more me - and you - a friend of mine was willing and able to write the necessary software - HDTAPE - which is now available at a shareware price. Tim Grams, author of HDFORMAT (the very popular SCSI hard drive formatting software), is the author of HDTAPE. (If you are already familar with HDFORMAT or any of Tim's other software products, you already appreciate the quality of his work!) HDTAPE is NOT a tape driver; rather, it is a ProDOS-8 application which allows you to format, backup to and restore from tape. As a ProDOS-8 application, the version of HDTAPE described here is specific for the Apple //gs. A GS/OS version as well as a version for the Apple //e are planned, and current owners of HDTAPE will be notified of the availability of significant upgrades. HDTAPE is available by direct order from Tim, and ordering information follows this article. If you're a SCSI hard drive owner who has quickly tired of backing up your drive to floppy disk, read on: I will lead you through the purchase of the hardware, its assembly and use. And before you say "I can't build anything" let me say that if you can use a screwdriver, you CAN build your own SCSI tape backup system - its THAT easy! Why A Duck? (Why a SCSI Tape Backup System?) Do you find yourself asking, "Why should I invest in a tape backup system when 3.5" disks will do?" There are three reasons which come to mind instantly: (1) Using 3.5" disks, you must remain glued to the chair in front of your system, swapping disks - lots of disks - and for a 32 meg volume this can take well over one hour. Using a tape system, you start it up, wander off and do other things while the system is backing itself up, and return when its done. (2) The tape system I'll describe here uses DC2000 tapes, each of which holds 40 megs, equivalent to 50 3.5" disks. Since the DC2000 tapes (which are also used in many of the MS-DOS systems and are therefore readily available) can be purchased for as low as $15 each, tape backup is more economical than disk backup. (3) And finally, since the DC2000 tape is roughly the size of an audio cassette, it requires a lot less storage space than do 50 3.5" disks. Lincoln Logs (The Hardware) The hardware needed for this project is listed below. I provide information on vendors and approximate prices (based on what I paid in March 1989) at the end of this article. 1 - 3M brand MCD-40 DM/SCSI tape unit 1 - Tulin AppleHive case with 30 watt power supply & fan; includes all internal cabling; the optional open face plate is highly recommended 1 - Apple SCSI Interface Card (ROM version C) 1 - SCSI Interface Cable terminating in a DB-25 pin connector on one end and Centronics-like 50- pin connector on the other end 1 - Standard Power Cord (as used on the Apple // line) 1 - DC2000 40 meg (250') SCSI tape cartridge 1 - HDTAPE (Formatting, Backup & Restore Software) Ummm...A Frozen TV Dinner! (The Assembly) For the initial assembly and connection, I'm going to provide directions assuming that your SCSI tape backup system will be operating on a seperate Apple SCSI Interface card from your hard drive. Operation on the same SCSI chain (i.e., Interface Card) as your hard drive requires a few extra steps, which will also be explained. 1. If your tape unit arrived with the attachment brackets already installed, skip down to Step 3. 2. Attach the brackets to either side of the tape unit using the 4 screws supplied. When facing the tape unit's front panel, the tape ejection button should be below the tape insertion opening. 3. If you purchased the optional open face plate from Tulin, skip to Step 4; if not, you will need to cut a hole in the face plate: Using a sabre saw with sheet metal blade, cut a rectangular hole in the AppleHive face plate measuring 4.25" wide and 1.5" high. The lower left corner of this hole should be 1" from the left edge and 0.25" up from the bottom of the face plate (on the bottom half of the face plate when facing the AppleHive). When cutting this hole, be sure to make the cut far away from the tape unit itself - preferrably in another room - to keep metal shavings from coming in contact with the drive and case. Use a metal file to round the cut edges smooth. 4. With one hand, hold the tape unit so that its underside is facing UP. (The tape's eject button is on the bottom front of the unit.) With your other hand, grab the distal end of the flat, 50-wire ribbon cable coming from the connectors on the back plate of the case and extend the cable so that it is NOT twisted. Insert the connector at the end of this cable into the 50-pin connector at the back of the tape unit. Be careful to insert this connector properly so that no pins are bent, broken or sticking out. When you press the connector into the back of the tape unit, the latches on either side of the tape unit's connector should lock the cable in place. Once this connection has been secured, rotate the