jsweet@ICS.UCI.EDU (Jerry Sweet) (08/15/86)
This has probably been asked before, BUT at least not since mid-May, which is how far back our info-vax archives go. My limited experience with MicroVAX-II diskettes has been: "Digital" brand floppies work in the drives, but others do not. Is there anything really special about Digital's floppies, e.g. pre-formatting or some other marketing conspiracy? Has anyone had a successful experience with non-Digital floppies? I've never heard of a (commonly available) >96tpi diskette, but is that what's required? What's the story? -jns
8250480@UWAV4.BITNET.UUCP (08/17/86)
> Subject: uVAX-II diskettes > Date: Thu, 14 Aug 86 20:45:37 -0800 > From: Jerry Sweet <jsweet@ICS.UCI.EDU> > > My limited experience with MicroVAX-II diskettes has been: "Digital" > brand floppies work in the drives, but others do not. Is there > anything really special about Digital's floppies, e.g. pre-formatting > or some other marketing conspiracy? Has anyone had a successful > experience with non-Digital floppies? I've never heard of a (commonly > available) >96tpi diskette, but is that what's required? What's the > story? As I understand it, the diskettes you use are Digital's RX50's. This is a special format diskette designed especially for Digital personal computers and micro-systems. Factory preformatting is supposed to save time and aid drive-to-drive interchangeability. I own a DEC Rainbow (which also uses these diskettes). However, the diskette (re)formatter program under CP/M in effect produces RX50's from any blank diskette... I use Nashua brand, double-sided, double- density, diskettes simply because I can get them for approximately $7 per box of 10 (with sleeves, labels, write-protect tabs) as compared to Digital's current price of $32 (I think it used to be $50) per box of 10. These DEC machines only use one side, I only use the double- sided diskettes because I get them cheaper than single-sided. In summary, I think you can use any double-density diskette, you'll just need to run it through the FORMAT program under CP/M on a Rainbow... As I understand it, there is no way to format these on the Micro-VAX. Digital wants you to either buy their Rainbow PC, or spend mega-bucks on their floppies (rather devious). The 96tpi floppies are supposed to be higher "quality" than double-density, though in my opinion this is just a marketing ploy to get more money out of you! If there is a problem with the "quality" the formatter program should find it (in which case you can discard that one problem diskette). I haven't had a "problem diskette" yet. You should be aware of Digital's warning NOT to use diskettes with reinforced hub-rings. Though I have "occasionally" fed my Rainbow a diskette with hub-ring without any problems. In summary, find someone with a Rainbow where you can "make" all the "RX50's" you desire... If you cannot do this, other companies (BASF comes to mind) also make RX50's which can be had for much cheaper! Hope this helps! -- Erik A. Abers -- 501 N. 36th. St. #167 -- University of Washington -- Seattle, WA 98103; USA Bitnet: 8250480@UWAV4.BITNET Arpanet: 8250480%UWAV4.BITNET@WISCVM.ARPA Usenet: 8250480%UWAV4.BITNET@WISCVM.WISC.EDU
hoffman%pitt@CSNET-RELAY.ARPA (Bob Hoffman) (08/19/86)
>From: jsweet@ICS.UCI.EDU > >My limited experience with MicroVAX-II diskettes has been: "Digital" >brand floppies work in the drives, but others do not. Is there >anything really special about Digital's floppies, e.g. pre-formatting >or some other marketing conspiracy? Has anyone had a successful >experience with non-Digital floppies? I've never heard of a (commonly >available) >96tpi diskette, but is that what's required? What's the >story? > >-jns Digital RX50 diskettes are indeed pre-formatted, and there appears to be no way to format blank (i.e. degaussed) diskettes in DEC drives, except for those on the Rainbow. This is right in keeping with DEC's "tradition", as neither the RX01 nor the RX02 could format a blank diskette. Third-party RX50-compatible drives are usually able to do this formatting. Maxell, Verbatim, and others market pre-formatted RX50 diskettes. If you are interested, the RX50 format is as follows: - Single Sided - 80 track (96 tpi) - 10 sectors/track - 512 bytes/sector I believe one of the third-party controllers (Andromeda? Emulex?) allows use of double-sided drives in an upward-compatible fashion. Why didn't DEC go with double sided drives? The technology had certainly been proven by the time the RX50 was introduced. -- Bob Hoffman, N3CVL {allegra, bellcore, cadre, idis, psuvax1}!pitt!hoffman Pitt Computer Science hoffman%pitt@csnet-relay