gst@gnosys.UUCP (Gary S. Trujillo) (07/28/89)
I recently discovered a Boston-area source (which does mail-order) for
the Micropolis model 1355, which has a formatted capacity of 159 Mbytes
(it's 170 Mbytes unformatted). The drive has eight heads with 1024
cylinders, so I'm assuming it wouldn't require the P5.1 upgrade, though
it would need the WD2010 chip (right?). It uses the MFM recording scheme,
and has an access time of about 22msec, I believe. The price is $799
(plus an extra $25 for repackaging if you order less than four).
Anyway - does anyone know whether this drive could be used with the 3B1?
(I'm assuming it's a full-height, since the 1335, which has a lower capacity
is itself full-height. I have the 67Mbyte model 3B1, so the enclosure is no
problem.)
I sent a note to C. M. Votava, who posted a disk list back in February,
but my message bounced. If he sees this, he's invited to send me an
address, so I can pass on any information I get. I'll also summarize my
findings to the net, and will pass on the name of the dealer, if there's
interest.
--
Gary S. Trujillo {linus,bbn,m2c}!spdcc!gnosys!gst
Somerville, Massachusetts {ima,stech,wjh12}!gnosys!gstgst@gnosys.UUCP (Gary S. Trujillo) (07/28/89)
In article <254@gnosys.UUCP> gst@gnosys.UUCP (myself) writes: > I recently discovered a Boston-area source (which does mail-order) for > the Micropolis model 1355... Len Rose (I don't think he'll mind my mentioning his name) has informed me that the 1355 is an esdi device, and that he doesn't think the 3B1 will handle esdi drives. I'll let y'all know if the folks I mentioned have any other drives at good prices that anyone might suggest. -- Gary S. Trujillo {linus,bbn,m2c}!spdcc!gnosys!gst Somerville, Massachusetts {ima,stech,wjh12}!gnosys!gst
clewis@eci386.uucp (Chris Lewis) (07/28/89)
In article <254@gnosys.UUCP> gst@gnosys.UUCP (Gary S. Trujillo) writes: >I recently discovered a Boston-area source (which does mail-order) for >the Micropolis model 1355, which has a formatted capacity of 159 Mbytes >(it's 170 Mbytes unformatted). The drive has eight heads with 1024 >cylinders, so I'm assuming it wouldn't require the P5.1 upgrade, though >it would need the WD2010 chip (right?). What it needs is an ESDI controller. The Micropolis 1355 has an ESDI interface, the WD2010 (and supportable 3b1 drives) are ST506. >Anyway - does anyone know whether this drive could be used with the 3B1? Not unless somebody's selling an ESDI controller for the 3b1. Rule of thumb: 5.25" ST506 drives have 8 1K or 17 512 byte sectors per track (yeah, some controllers are one more or less). Eg: roughly 8-9K per track. Multiply by # heads and # cylinders. The reason why I caught this one is that 8 heads and 1024 cylinders would be an 85 Mb drive in normal situations (eg: Maxtor XT1085, Micropolis 1325 or Miniscribe 6085). Since it had *twice* the storage that it should have for it's geometry, it had to be something other than ST506/MFM - ESDI usually averages 34 512 byte sectors/track. If it had been only %50 larger, I would have suspected RLL - which isn't available for 3b1s either. I believe that the max fully legal (w.r.t. the ST506 interface standard) size for a ST506 is 15 heads and 1024 cylinders, which works out to about 140Mb unformatted. For that you need the WD2010. In the case of IBM AT style machines, it is possible to obtain controllers that play tricks with ESDI or SCSI drives to make them look like monster ST506's (eg: the 64 sector/track fudge in Adaptecs and WD1007s), but, sorry, nobody's got 'em for 3b1s as far as I know. -- Chris Lewis, R.H. Lathwell & Associates: Elegant Communications Inc. UUCP: {uunet!mnetor, utcsri!utzoo}!lsuc!eci386!clewis Phone: (416)-595-5425