meulenbr@cstw01.UUCP (Frans Meulenbroeks) (08/05/88)
Hi!
I have laid my hands on an ESDI disk, which I would like to interface to
an atari ST. However, being out-of-hardware for several years now, I'm
having some questions:
1) What exactly is ESDI? Where can I find the spec, who can recommend a
book or an article on this subject?
2) How does ESDI relate to ST506/ST412? and to SCSI ??
3) I know how to interface a disk with a ST506/ST412 or SCSI interface to
the ST. Is it doable to convert ESDI to either of these?
(Big wish:) Anyone by any chance aware of affordable boards to do
this? Magazine articles ??
4) Is it doable what I want to do? Any advice, help, hint etc. is very
very welcome.
(FYI: the drive in question is a Micropolis 1355)
Any response is greatly appreciated, and many thanks for your help!!
--
Frans Meulenbroeks
Centre for Software Technology
...!mcvax!philmds!prle!cst!meulenbr or ...!uunet!prlb2!cst!meulenbr
or perhaps meulenbr@cst.prl.philips.nlcww@ndmath.UUCP (Clarence W. Wilkerson) (08/09/88)
In article <168@cstw01.UUCP>, meulenbr@cstw01.UUCP (Frans Meulenbroeks) writes: > > I have laid my hands on an ESDI disk, which I would like to interface to > an atari ST. However, being out-of-hardware for several years now, I'm > very welcome. > or perhaps meulenbr@cst.prl.philips.nl Adaptec makes such a board. One supplier is Computer Surplus Store, which advertises in BYTE and Computter Shopper. It might run $120 or so.
markb@denali (08/10/88)
In article <1200@ndmath.UUCP>, cww@ndmath.UUCP (Clarence W. Wilkerson) writes: > In article <168@cstw01.UUCP>, meulenbr@cstw01.UUCP (Frans Meulenbroeks) writes: > > > > I have laid my hands on an ESDI disk, which I would like to interface to > > an atari ST. However, being out-of-hardware for several years now, I'm > > very welcome. > > or perhaps meulenbr@cst.prl.philips.nl > Adaptec makes such a board. One supplier is Computer Surplus Store, > which advertises in BYTE and Computter Shopper. It might run $120 or so. This is not an inexpensive solution, as you need a slot and you will need to do some driver work for this board. You may want to talk to Micropolis about getting a recommendation on what they use to do similar work. markb
sreeb@pnet01.cts.com (Ed Beers) (08/10/88)
I don't think the hardware should be to hard. You need just about the same
set up all of us are using. An Atari to SCSI adapter and a SCSI to ESDI
adapter ( rather than the SCSI t506 adapter normally used). These are
available from Adaptec. If the software interface is compatible with the
other Adaptec controller you should be all set. Otherwise ....
Good luck.
UUCP: {cbosgd hplabs!hp-sdd sdcsvax nosc}!crash!pnet01!sreeb
ARPA: crash!pnet01!sreeb@nosc.mil
INET: sreeb@pnet01.cts.comjlohmeye@entec.Wichita.NCR.COM (John Lohmeyer) (08/10/88)
I tried to send this by e-mail, but it was returned -- sorry. In article <168@cstw01.UUCP> Frans Meulenbroeks writes: >I have laid my hands on an ESDI disk, which I would like to interface to >an atari ST. However, being out-of-hardware for several years now, I'm >having some questions: > >1) What exactly is ESDI? Where can I find the spec, who can recommend a > book or an article on this subject? ESDI stands for Enhanced Small Device Interface. It is a draft proposed American National Standard. If it is approved, it will become an ANSI standard. You can buy a copy from Global Engineering Documents for $30.00. They know it as X3.170-198X and are at 800-854-7179 or 714-261-1455. There is also an electronic copy of the WordStar files for this document on the SCSI Bulletin Board at 316-636-8700 (I'm the Sysop). >2) How does ESDI relate to ST506/ST412? and to SCSI ?? ESDI uses similar connectors to ST506, but it is a different protocol -- the data separator is in the drive, instead of the controller. SCSI is an intelligent interface (controller to system) instead of a device level interface like ST506 and ESDI (drive to controller). Embedded SCSI drives include the controller in the drive. >3) I know how to interface a disk with a ST506/ST412 or SCSI interface to > the ST. Is it doable to convert ESDI to either of these? > (Big wish:) Anyone by any chance aware of affordable boards to do > this? Magazine articles ?? Yes, you can easily go from SCSI to ESDI. Several manufacturers make such controllers, including NCR (800-325-SCSI). ----- j.lohmeyer@Wichita.NCR.COM
henry@utzoo.uucp (Henry Spencer) (08/10/88)
In article <168@cstw01.UUCP> meulenbr@cst.UUCP () writes: >1) What exactly is ESDI? ... >2) How does ESDI relate to ST506/ST412? and to SCSI ?? ESDI is sort-of-kind-of an improved ST506/412. It was designed to be a better and faster drive-to-controller interface. Its relationship to ST506/412 is as a (superior) competitor. It is unrelated to SCSI, which is a controller-to-host interface. >3) I know how to interface a disk with a ST506/ST412 or SCSI interface to > the ST. Is it doable to convert ESDI to either of these? Much the same techniques used for 506/412 interfacing should be applicable, I would guess -- I'm not up on the details -- but converting ESDI to 506/412 is probably not practical; they differ too much in details. Converting ESDI to SCSI basically means buying a disk controller that talks ESDI to disks and SCSI to the host; finding such on the commercial market shouldn't be hard, since SCSI is common nowadays and ESDI is increasingly widespread too. -- Intel CPUs are not defective, | Henry Spencer at U of Toronto Zoology they just act that way. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
vixie@decwrl.dec.com (Paul Vixie) (08/13/88)
henry@utzoo.uucp (Henry Spencer) writes:
# ESDI is sort-of-kind-of an improved ST506/412. It was designed to be a
# better and faster drive-to-controller interface. Its relationship to
# ST506/412 is as a (superior) competitor. It is unrelated to SCSI, which
# is a controller-to-host interface.
This is a visual and semantic problem that causes a great deal of confusion.
In ST506 and ESDI, there is a board on the system IO bus (or some chips and a
port on the motherboard) to which one attaches a cable; the other end of this
cable is attached to a disk drive.
In SCSI, there is STILL a board on the system IO bus (or some chips and a
port on the motherboard) to which one attaches a cable; the other end of this
cable is attached to a disk drive, which has an on-drive disk controller.
It's just that in ST506 and ESDI,
we call the board-on-the-bus or chips-on-the-motherboard a
"controller" and the cable running to the drive(s) is called a
"drive-to-controller interface",
while in SCSI,
we call the board-on-the-bus or chips-on-the-motherboard a
"SCSI interface" and the cable running to the on-drive disk
controller is called a "controller-to-host interface".
To most people, there's still just a board in the machine and a cable going
to a disk drive. The fact that the board is called an "interface" in SCSI
because the controller is in the drive doesn't change the common terminology
of calling the board in the CPU cabinet a "controller".
It is more accurate to call it an "interface", of course, because the
controller (the thing that deals with the MFM or whatever modulation the
drive uses) is in fact elsewhere.
It all hangs on calling the board a "controller" when in SCSI, it's an
"interface". I can't repeat that too many times -- us board-swappers
that don't learn the details of things are easily confused by details
like this one.
(I don't mean that _you_ are confused, Henry -- it's just that your answer
didn't really ease the confusion that had prompted the question.)
--
Paul Vixie
Digital Equipment Corporation Work: vixie@dec.com Play: paul@vixie.UUCP
Western Research Laboratory uunet!decwrl!vixie uunet!vixie!paul
Palo Alto, California, USA +1 415 853 6600 +1 415 864 7013