steve@ncrcce.StPaul.NCR.COM (Steven Engelhardt) (11/17/89)
Does someone have a current list of drives usable for a 3b1 with or without the WD2010 or P5.1 upgrades. There are many new disks available now in both full and half height. Any info would be apreciated. -- Steven Engelhardt ENGELHARDT@STPAUL.NCR.COM NCR Comten ..uunet!ncrlnk!ncrcce!steve Development Computer Center, MS: S015 612-638-7223 NCR-652-7223 2700 Snelling Ave. N. StPaul, MN 55113 We are observing your Earth.
flinton@eagle.wesleyan.edu (11/18/89)
In article <1727@ncrcce.StPaul.NCR.COM>, steve@ncrcce.StPaul.NCR.COM (Steven Engelhardt) writes: > Does someone have a current list of drives usable for a 3b1 > with or without the WD2010 or P5.1 upgrades. There are > many new disks available now in both full and half height. > Any info would be apreciated. -- here, too, please. -- Fred E.J. Linton, flinton@eagle.Wesleyan.EDU, Math. Dept., Wesleyan U., Middletown, CT 06457 USA (msg @ 1 203 776 2210)
bdb@becker.UUCP (Bruce Becker) (11/21/89)
In article <1727@ncrcce.StPaul.NCR.COM>, steve@ncrcce.StPaul.NCR.COM (Steven Engelhardt) writes: | Does someone have a current list of drives usable for a 3b1 | with or without the WD2010 or P5.1 upgrades. There are | many new disks available now in both full and half height. | Any info would be apreciated. In general, any drive which works with a standard IBM XT or AT controller with a ST-506 interface ought to work fine. You can't reference more than 1024 tracks without the P5.1 upgrade, and you can't reference more than 8 heads without the WD2010. The chip doesn't require the upgrade, & the upgrade doesn't require the chip. It is possible to use RLL drives but you will only get 2/3 of the rated capacity, since the tracks will be formatted with only 17 512-byte sectors. It would be useful for people to post any known exceptions to this generality. Cheers, -- ^^ Bruce Becker Toronto, Ont. w \**/ Internet: bdb@becker.UUCP, bruce@gpu.utcs.toronto.edu `/v/-e BitNet: BECKER@HUMBER.BITNET _/ >_ Ceci n'est pas une | - Rene Macwrite
mvadh@cbnews.ATT.COM (andrew.d.hay) (11/22/89)
In article <1145@becker.UUCP> bdb@becker.UUCP (Bruce Becker) writes:
[]
" You
" can't reference more than 1024 tracks without
" the P5.1 upgrade, and you can't reference
" more than 8 heads without the WD2010.
this is backwards; it's the 2010 that gives you access to more tracks,
and the P5.1 logic that adds access to more cylinders.
" The
" chip doesn't require the upgrade, & the upgrade
" doesn't require the chip.
true.
" It is possible to use
" RLL drives but you will only get 2/3 of the
" rated capacity, since the tracks will be
" formatted with only 17 512-byte sectors.
also true. the unix-pc only supports MFM...
--
Andrew Hay +------------------------------------------------------+
42 Authority | Zaphod Beeblebrox is now appearing in |
AT&T-BL Ward Hill MA | "No S*x Please, We're Amoeboid Cingatularians" |
a.d.hay@att.com +------------------------------------------------------+jcm@mtunb.ATT.COM (John McMillan) (11/23/89)
By now Bruce has probably had some sleep and begun to regret his posting: In article <1145@becker.UUCP> bdb@becker.UUCP (Bruce Becker) writes: : > In general, any drive which works with a > standard IBM XT or AT controller with a > ST-506 interface ought to work fine. You > can't reference more than 1024 tracks without > the P5.1 upgrade, and you can't reference > more than 8 heads without the WD2010. The - P5.1 supports 9 -> 16 heads - WD2010 supports 1025 -> 2047 heads - Note that early kernels (3.0? 3.5?) may not support > 1024 cylinders. > chip doesn't require the upgrade, & the upgrade > doesn't require the chip. It is possible to use > RLL drives but you will only get 2/3 of the > rated capacity, since the tracks will be > formatted with only 17 512-byte sectors. - _I_ wouldn't use RLL, but lack details. It is my recollection that the electronics just ain't THE SAME and at least boundary-condition problems might occur. (Go ask someone who KNOWS -- NOT ME.) > It would be useful for people to post any > known exceptions to this generality. - The WD chip registers are set for write-pre-compensation at cylinder 128. How sensitive your disk is to this ain't my concern!-) Geee... I think this posts exceptions to all-but-one statement, Bruce!-) john mcmillan -- att!mtunb!jcm -- speaking for self, not THEM (And rushing off for lamb vindaloo without reviewing the nonsense I've posted above.)
jcm@mtunb.ATT.COM (John McMillan) (11/23/89)
O yes! Forgot to mutter that the limit of the WD1010 is 1024 CYLINDERS, not tracks -- unless you're using a single-surface disk !-) john mcmillan -- att!mtunb!jcm -- speaking for self, not THEM (And STILL rushing off for lamb vindaloo.)
jcm@mtunb.ATT.COM (John McMillan) (11/23/89)
I've noticed I was in too much of a curry for lunch: In article <1704@mtunb.ATT.COM> jcm@mtunb.UUCP (John McMillan) writes: : > - WD2010 supports 1025 -> 2047 heads 2048 CYLINDERS john mcmillan -- att!mtunb!jcm
kevin@kosman.UUCP (Kevin O'Gorman) (11/24/89)
Drat. This is going to confuse a lot of folks. The correction is still not as clear as it should be: In article <11654@cbnews.ATT.COM> mvadh@cbnews.ATT.COM (andrew.d.hay,54242,wi,1d007,508 374 5484) writes: >In article <1145@becker.UUCP> bdb@becker.UUCP (Bruce Becker) writes: >[] >" You >" can't reference more than 1024 tracks without >" the P5.1 upgrade, and you can't reference >" more than 8 heads without the WD2010. > >this is backwards; it's the 2010 that gives you access to more tracks, This should read "cylinders" ^^^^^^ >and the P5.1 logic that adds access to more cylinders. and this should read "heads" or "surfaces" ^^^^^^^^^ > Both of these upgrades have the effect of adding to the number of tracks accessable. One does it by adding the tracks of additional cylinders, the other by adding tracks of additional surfaces.
wtm@neoucom.UUCP (Bill Mayhew) (11/24/89)
I've run into the abiguous meaning of the term, "track," enough that I find it rather aggrivating. In the IBM PC world, "track" often means the ring of data on one disk surface, while "head" describes the device used to gain access to the data on different disk surfaces. In the Unix PC world (and seemingly most other places), tracks are the disk surfaces, while cylinders are the concentric rings of data on the tracks. I think there are a few places where the Unix PC manuals slip up and refer to cylinders as tracks. And then there are the 512 byte physical versus 1024 byte logical disk blocks just to kee things fun too. Some commands use logical blocks, while others use physical blocks; the manual doesn't always tell which, so guessing and experimentation is reuqired. Where this mess gets confusing is where you run into smart disk controllers that do virtual mapping so that the number of tracks and cylinders is approximately equal; some ESDI controllers, for instance. The Adaptec controller that IBM uses in the model 80 comes to mind.