Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!sdd.hp.com!caen!math.lsa.umich.edu!math.lsa.umich.edu!hyc From: hyc@math.lsa.umich.edu (Howard Chu) Newsgroups: comp.sys.atari.st Subject: Re: Standard Hard Drive Interfaces? Message-ID: <1990Nov19.225916.15168@math.lsa.umich.edu> Date: 19 Nov 90 22:59:16 GMT References: <1990Nov16.003735.14049@contact.uucp> <1990Nov17.032431.25272@cs.odu.edu> Sender: usenet@math.lsa.umich.edu Distribution: na Organization: University of Michigan Math Dept., Ann Arbor Lines: 104 In article <1990Nov17.032431.25272@cs.odu.edu> src@cs.odu.edu (Scott R. Chilcote) writes: >In article <1990Nov16.003735.14049@contact.uucp> rrwood@contact.uucp (roy wood) writes: >>Someone posted an ad for used ST equipment and made mention of "a Supra Hard >>Drive Interface" and a Seagate hard drive. From this I infer that Supra >>markets an interface that allows one to use a nice cheap IBM style hard-drive >>on one's ST. Is this correct? And if it is so cheap to get set up with the >>interface and drive, why would anyone choose anything else for his or her ST? >Why wouldn't anyone want to buy an interface and use a standard hard disk? >Is that your question? >Here's my answer... >A Supra hard drive interface costs $100, if you can still get one. There is >a better product out now (I should know, I bought the Supra) from ICD, and it's >about $130 mail order. This is called a HOST ADAPTER. Everything is an >interface these days, so let's keep things clear. I just bought an ICD host adapter last week, for around $84. This is their Advantage ST, minus clock, which I didn't need for use in my Mega. Their AdSCSI ST Plus has the clock, and is 10-20 bucks more, and also about twice the size. >The Host Adapter plugs into the ST's DMA port (one of the very wise parts of >an ST) and converts these signals to be SCSI compatible. You can have up to >10 DMA devices, and data rates have the potential to be 2 Megs per second >through this port. Fast! Just to add here - the ICD docs say they support the full SCSI command set, and will also support SCSI-2 commands. Sounds cool to me, tho I've yet to obtain any hardware that needs the SCSI-2 compatibility... >Okay, so that's a start. You mentioned cheap IBM-PC style drives. But now we >only have SCSI compatibility. Whoops! So you need to convert from SCSI to >ST-412/506 now, if you want to use an off-the-shelf MFM or RLL-encoded PC type >hard disk. What now? >Well, the best and easiest choice is to get an SCSI compatible drive instead. I concur. These are the best performance drives, anyway... >This costs $30-$150 more than an equivalent ST-412/506 hard disk. The other >choice is to buy a second "adapter", which converts from SCSI to ST-412/506. >These come in both MFM and RLL flavors, and Adaptec is a good choice. They >sell them for about $130, depending on the model. It will let you connect >TWO cheap PC-type hard disks with one board. An extra savings... I've often wondered if that was the way to go... more drives per controller sounds like a good idea, dunno why. Just a gut feeling. >But now you need a hard disk, and hopefully one that's supported by the Supra >or ICD formatting software. Otherwise you need a lot of specific information >about your disks. And you need a box. And you need a power supply. And you >need cabling. And you need the luck of the Irish, because if just one of all >those connections you made is flaky, it is a long, arduous trail. It takes >very sophisticated equipment to debug a hard disk setup -- or lots of trial and >error. Hey, I have a shoebox case with 40 watt power supply I will be trying to get rid of Real Soon now... It ran a Quantum 80 and Miniscribe 8425S faithfully for 2 years. (Setup for 2 half-height or 1 full-height drive, power for 2 drives plus fan.) I guess you do need luck in getting good parts, I haven't had trouble on this end yet. You *do* need to be *incredibly* careful about the cabling though... That's why I'm selling this case and power supply, and needed a new host adapter last week, 'cause I wasn't careful enough. Don't ever ever ever plug a SCSI cable in backwards. I fried my old Supra host adapter and my Quantum drive. (Really fried the host adapter. smoke, vaporized PCB traces, the works. Sigh. And that one had a working clock and battery on it...) Needless to say, mistakes can be very expensive. I still have to get my drive repaired. >If you approach the chore correctly, you can do all this, save $50 - $200 over >the cost of a mail-order ready made hard drive, and have a dependable machine. >If, say, you get a bad part in the mail (which one) it is sheer hell. I went >through all of this about two years ago, and wound up with a 65 Meg hard disk >after six months of struggle. Not only did I get a bad hard disk, I got a bad >Adaptek SCSI-RLL adapter! >I'd still do it again, rather than buy a new setup. It has run without fail >since then, and I need more space now. Heh - that was the exact reason I got started on this ordeal... Got a Syquest drive and needed to move to a bigger case to hold everything. Mounted the Quantum upside down relative to its old position, didn't notice that I now needed to twist the cable around to match... Plugged everything in straight, and boom. At least the other drives didn't smoke too, I would've probably thrown everything out the window at that point. Oh well. So now I have a brand new Syquest staring at me, waiting for me to fill some cartridges (this is neat!) with data. Of course, I *had* been planning to use it to back up my Quantum....... Sigh. 88 megs, and nothing to do. Don't let this happen to you... I still think it's worthwhile to build your own system, if you're at least half competent. (As obviously I am not. Sheesh.) Mail order places sell these Syquest packages for around $700-900, and I got mine for about $500, plus the $85 for the unexpected expense of a new host adapter... -- -- Howard Chu @ University of Michigan Mac// - adv., q.v. MacToo, e.g. McHave a McHappy McDay! McThanks, McYou MacToo!