kevin@arnor.UUCP (Kevin Goroway) (07/21/89)
Well, I asked this question before, and all I got were more questions; "Why?" Well!? Are there any ESDI controllers available for the amiga? A simple 'no' or a simple 'yes' would do just fine, but if the answer is 'yes' I would love some information as to where and how much... thanks... -Kevin -- =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= - Worcester Polytechnic Institute|"It happens sometimes, people just explode, - = Worcester, MA (IBM for summer) | natural causes." -Repo Man = -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
cmcmanis%pepper@Sun.COM (Chuck McManis) (07/22/89)
In article <339@arnor.UUCP> kevin@arnor.UUCP (Kevin Goroway) writes: >Well!? Are there any ESDI controllers available for the amiga? >A simple 'no' or a simple 'yes' would do just fine, but if the answer is 'yes' >I would love some information as to where and how much... First some definitions, there are several levels of drive interface. LEVEL 1) Drive Control Interface Level (current standards ST-506, ESDI, SMD) This interface defines which pins on the connector to the drive control stepping the heads, which direction they step, serial data to and from the R/W heads, and status information such as sector positioning, track 0 detect etc. LEVEL 2) Storage Device Interface Level (stds SCSI and IPI) This interface logically divides a device into blocks of arbitrary size, and establishes a messaging protocol for making requests and receiving data and status from a storage device. LEVEL 3) Host Interface Level (A2090A, HardFrame, SupraDrive, ...) This is the buffer interface between the internal interface of the host, and one or more Storage Device Interface standards. Going from Level 3 to Level 1 requires three separate interfaces. The Hard Disk interface card provides the first, the SDI card provides the second, and the DCI card provides the third. Any or all of these "levels" can be combined physically on one interface. For example, the A2090 card interfaces between the A2000 Bus interface to the SCSI storage device interface. However is also provides a translation from the A2000 bus interface to the ST506 Drive Control interface. On the other side of the coin, the Conners SCSI drives provide both the SCSI storage device interface and the drive control interface on the same drive. An example of a three card interface would be : A2090 ----(SCSI)---->Adaptec 4000A----(ST506)---> Drive An example of a one card interface would be : A2090 ----(ST506)----> Drive To use an ESDI drive you would have to setup something like : Interface ----(SCSI)---->Adaptec 5000A----(ESDI)---->Drive (check the adaptec number before ordering it) There is also a software caveat. When you use an external to the drive interface board, the board doesn't know ahead of time what kind of drive it is talking to in terms of cylinders, heads, etc. You have to initialize it somehow. Most manufacturers make the board read sector 0,0,0 off the drive for this information on powerup so you only have to do it once. Anyway, there isn't a solution for that yet except for some hacks. The hardware is readily available though. --Chuck McManis uucp: {anywhere}!sun!cmcmanis BIX: cmcmanis ARPAnet: cmcmanis@sun.com These opinions are my own and no one elses, but you knew that didn't you. "A most excellent barbarian ... Genghis Kahn!"
lphillips@lpami.wimsey.bc.ca (Larry Phillips) (07/24/89)
In <12239@grebyn.com>, ckp@grebyn.com (Checkpoint Technologies) writes: > Commodore makes the only ST506 controller for the Amiga, the A2090(A). Aside >from this, every Amiga hard disk adapter is SCSI. Why? SCSI is the cheapest >adapter to build, that's the main reason. While it may be true in the _strictest_ sense of the word that CBM makes the only ST506 controller, there are most definitely other ST506 solutions for the Amiga, or in other words, NOT every hard disk adapter for the Amiga is SCSI. The Wedge comes immediately to mind, and I know there are a couple of other products that allow the use of IBM-style ST506 controllers. >Then, the disclaimer: All expressed opinions are, indeed, factual. \ / o You might consider changing this for the time being. -larry -- "So what the hell are we going to do with a Sun?" - Darlene Phillips - +-----------------------------------------------------------------------+ | // Larry Phillips | | \X/ lphillips@lpami.wimsey.bc.ca -or- uunet!van-bc!lpami!lphillips | | COMPUSERVE: 76703,4322 -or- 76703.4322@compuserve.com | +-----------------------------------------------------------------------+
ckp@grebyn.com (Checkpoint Technologies) (07/24/89)
In article <339@arnor.UUCP> kevin@arnor.UUCP (Kevin Goroway) writes: >Well!? Are there any ESDI controllers available for the amiga? Actually, no. The best you can do is get a SCSI adapter and hook it to an Adaptec SCSI ESDI controller. Commodore makes the only ST506 controller for the Amiga, the A2090(A). Aside from this, every Amiga hard disk adapter is SCSI. Why? SCSI is the cheapest adapter to build, that's the main reason. -- First comes the logo: C H E C K P O I N T T E C H N O L O G I E S / / \\ / / Then, the disclaimer: All expressed opinions are, indeed, factual. \ / o Now for the witty part: I'm pink, therefore, I'm spam! \/