boz@eleazar.dartmouth.edu (John Boswell) (05/04/89)
Hi. Our office currently has a MacPlus w/ 2.5meg and an external 20meg harddisk. We also have a 512ke that has been upgraded with a Dove upgrade to 2meg and a SCSI port. What I would like to know is if there is a reasonably cheap way to allow BOTH macs to use the (single) harddisk. Do I have to buy some fancy server software? Thanks for any info, ************************************************************************* John Boswell boz@eleazar.dartmouth.edu Dept. of Chemistry boz@dartCMS1.BITNET Dartmouth College, Hangover, Nude Hampster 03755
chari@nueces.UUCP (Chris Whatley) (05/05/89)
In article <13346@dartvax.Dartmouth.EDU>, boz@eleazar.dartmouth.edu (John Boswell) writes: > Our office currently has a MacPlus w/ 2.5meg and an external 20meg > harddisk. We also have a 512ke that has been upgraded with a Dove upgrade > to 2meg and a SCSI port. What I would like to know is if there is a reasonably > cheap way to allow BOTH macs to use the (single) harddisk. Do I have to buy > some fancy server software? Definitely get Tops. It is a cheap and simple way to accomplish this. All you need are two copies of tops and a couple of appletalk/phonenet connectors and voila, you have a network and file-sharing. It'll run you around $300 if you can find Tops cheaply enough. Chris -- Chris Whatley | "Thank you.. !bigtex!nueces!chari@cs.utexas.edu | Ah.. Thank me!" chari@walt.cc.utexas.edu | --Data 1607 Nueces,Austin TX 78723 - 512/453-4238 |
paisley@circus.cme.nbs.gov (Scott Paisley) (05/05/89)
In article <13346@dartvax.Dartmouth.EDU> boz@eleazar.dartmouth.edu (John Boswell) writes:
cheap way to allow BOTH macs to use the (single) harddisk. Do I have to buy
TOPS would allow you to do this BUT it would probably burden the mac
connect to the hardrive while the other mac was doing disk access.
What I would like to know is:
Can two macs access a single SCSI harddrive via hardware? That is,
partition the harddrive so that each mac has its own partition, and
each mac would connect to one of the scsi connectors on the drive.
Can this work? What happens when both macs try to write at the same
time?
Ok, you hardware guys, let's hear from you!
--
"...and this thing you call language - you depend on it for so much,
yet none of you are its master." -Carlos the Medusan
Scott Paisley paisley@cme.nbs.gov ..!uunet!cme-durer!paisleyarmstrng@cs.dal.ca (Stan Armstrong) (05/06/89)
In article <286@nueces.UUCP> chari@nueces.UUCP (Chris Whatley) writes: >In article <13346@dartvax.Dartmouth.EDU>, boz@eleazar.dartmouth.edu (John Boswell) writes: >> Our office currently has a MacPlus w/ 2.5meg and an external 20meg >> harddisk. We also have a 512ke that has been upgraded with a Dove upgrade >> to 2meg and a SCSI port. What I would like to know is if there is a reasonably >> cheap way to allow BOTH macs to use the (single) harddisk. Do I have to buy >> some fancy server software? > >Definitely get Tops. It is a cheap and simple way to accomplish this. All you >need are two copies of tops and a couple of appletalk/phonenet connectors >and voila, you have a network and file-sharing. It'll run you around >$300 if you can find Tops cheaply enough. There is an even cheaper way, if all you want is access to files on a remote hard disk. Get Silver Server ($89) from MacConnection. I have it for Silver Lining, the best hard disk driver software I have been able to find. I haven't yet installed Silver Server. I am recommending it for a small LAN at our church. If anyone has relevant experience please let me know my Email, as serveral decisions depend upon it. Stan Armstrong. Religious Studies Dept Saint Mary's University Halifax, N.S.,CANADA, B3H 3C3 (902)420-5866 USENET: att!clyde!watmath!water!dalcs!armstrng BITNET:ARMSTRONG@STMARYS.BITNET
mha@batcomputer.tn.cornell.edu (Mark H. Anbinder) (05/08/89)
In article <PAISLEY.89May5100342@circus.cme.nbs.gov> paisley@circus.cme.nbs.gov (Scott Paisley) writes: > >Can two macs access a single SCSI harddrive via hardware? That is, >partition the harddrive so that each mac has its own partition, and >each mac would connect to one of the scsi connectors on the drive. >Can this work? What happens when both macs try to write at the same >time? Considering that a Mac connected to a SCSI device is just a SCSI device itself, as far as the device is concerned, is there really any reason that you couldn't simply daisy-chain two computers on a SCSI chain and have both of them address the same disk drive the same way that one computer can address two disk drives? I'll admit I don't know how the SCSI protocol works (and I'm sure it shows :-) but this doesn't sound THAT impossible. -- Mark H. Anbinder ** MHA@TCGould.tn.cornell.edu NG33 MVR Hall, Media Services Dept. ** THCY@CRNLVAX5.BITNET Cornell University H: (607) 257-7587 ******** Ithaca, NY 14853 W: (607) 255-1566 ******* Ego ipse custodies custudio
mr2t+@andrew.cmu.edu (Michael Tod Rose) (05/08/89)
In article <PAISLEY.89May5100342@circus.cme.nbs.gov> paisley@circus.cme.nbs.gov (Scott Paisley) writes: > >Can two macs access a single SCSI harddrive via hardware? That is, >partition the harddrive so that each mac has its own partition, and >each mac would connect to one of the scsi connectors on the drive. >Can this work? What happens when both macs try to write at the same >time? Uh, 'fraid not. The way the SCSI protocol/hardware is designed is that there can only be one controlling device (ie. Macintosh) on a chain. Quoting here from *Technical Introduction To The Macintosh*: (great book, I highly reccomend it) "When two SCSI devices communicate with each other, one acts as the initiator and the other as the target. The intitiator asks the target to perform a certain operation, such as reading a block of data. A SCSI device typically has a fixed role...for instance, the Macintosh always acts as initiator.... Multiple initiators and multiple targets are allowed on a SCSI bus, but *only one Macintosh computer can be connected to a SCSI bus at a time.*" Since the two SCSI jacks on the back of your average hard drive form an effective "SCSI Thru" combo, putting two Macs on one drive would certainly confuse the hell out of everybody (both Macs have a SCSI id number of 7, so you're screwed right there) and might very well damage the drive or the Macs' SCSI chips. So, two Macs & one drive is wack. Don't do it. -mike ######################################################################### Mike Rose "I hope that one or two immortal lyrics will come mr2t+@andrew.cmu.edu out of all this tumbling around." Class of 1991 (I hope!) -Poet Louise Bogan on her affair Disclaimer: I work for a with poet Theo Roethke newspaper; they relish my opinions.
t-chrisk@microsoft.UUCP (Christopher Kinsmen) (05/10/89)
I don't believe that is a function of SCSI however. I believe it is due to the fact that all macs are SCSI ID 7 which causes a conflict on the SCSI bus. If we could change the SCSI ID theoretically we could have two initiators accessing the same disk. I believe this is possible for example with the Apple II SCSI card which allows you to set the machines SCSI ID. uw-beaver!microsoft!t-chrisk Chris Kinsman
ts@cup.portal.com (Tim W Smith) (05/15/89)
The SCSI ID is set in software. Just replace the SCSI Manager ( or patch it to use some other ID besides 7 ), and you are almost all set. Make sure the driver you are sharing is read-only, or you are likely to have two very confused machines ( and one *very* confused file system ). Tim Smith