wwc@newton.physics.purdue.edu.ARPA (William W. Carlson) (08/29/86)
I am considering the purchase of a hard disk to replace the 10 meg'er in my pc look-alike. I am intrigued by the disks advertised as for the "AT". Are these disks ST-506 compatible? Is the transfer rate (as opposed to the step rate) the same as disks for "XT" systems? I am particularly interested in the 30 meg CMI disk advertised for about $350. Any known problems with this disk? Please email replies to one of the addresses below. Thanks, Bill Carlson UUCP: ...!ihnp4!pur-ee!wwc ARPA: wwc@ec.ecn.purdue.edu
rdr@inuxh.UUCP (Robert Rindfuss) (09/01/86)
> I am considering the purchase of a hard disk to replace the 10 meg'er in > my pc look-alike. I am intrigued by the disks advertised as for the > "AT". Are these disks ST-506 compatible? Is the transfer rate > (as opposed to the step rate) the same as disks for "XT" systems? > I am particularly interested in the 30 meg CMI disk advertised for > about $350. Any known problems with this disk? > This has come up before, so I thought I'd post a reply. The only significant difference between the ST506 (used in XTs) and the ST412 (used in AT) drives has to do with track seeking - the 412 generally is a more intelligent drive, and is capable of doing "buffered seeks." This means the controller can blast a series of step pulses to the drive at a very fast rate, and the drive will buffer these, then move the heads in one operation to the desired track, rather than stopping to settle on each intermediate track. The good news for you is that any ST412 drive will work with an ST506 controller, as far as seeks are concerned. The worst that will happen is that the controller will not seek tracks as quickly as the drive might be capable of. The one thing to be sure first is that you can set your controller to handle the drive's number of heads and cylinders; the CMI 30meg has 6 heads and 640 cylinders. As for the CMI drives, I once put one of these on an AT&T 6300 using a DTC5150 controller - it worked just fine. It was one of the quietest drives I've ever (not) heard. I later returned the drive after getting cold feet about a drive from a company no longer in the drive business. But I think it was probably a good drive (not to be confused with the CMI 20meg drives of such notoriety in the IBM ATs, which had a different servo design.) By the way, I got it from a place called PC Systems in W. Palm Beach FL (305) 863-8447 for $279. Same drive BCE is selling for $350. I had a good experience with them, both buying the drive and later returning it. Bob Rindfuss AT&T Consumer Products, Indianapolis ...ihnp4!inuxh!rdr
owen@gt-eedsp.UUCP (Owen Adair) (09/04/86)
In article <465@newton.physics.purdue.edu.ARPA> wwc@newton.physics.purdue.edu.ARPA (William W. Carlson) writes: >I am considering the purchase of a hard disk to replace the 10 meg'er in >my pc look-alike. I am intrigued by the disks advertised as for the >"AT". Are these disks ST-506 compatible? Is the transfer rate >(as opposed to the step rate) the same as disks for "XT" systems? >I am particularly interested in the 30 meg CMI disk advertised for >about $350. Any known problems with this disk? > >Please email replies to one of the addresses below. We purchased two of these drives last week and found them to be solid, FAST and very quiet! This drive is, to saythe least, designed better than the 20 meg abortion they put in our AT's. At $350, it is the deal of the year. -- Owen Adair, Digital Signal Processing Lab, Ga. Institute of Technology uucp ... !{akgua,allegra,hplabs,ihnp4,seismo,ulysses}!gatech!gt-eedsp!owen Disclaimer: My employer is not responsible for, nor does it care, what I say here or anywhere else.