jdc@rama.UUCP (James D. Cronin) (05/05/88)
I recently went the homebrew route for a hard disk - Supra SCSI interface, Ataptec 4070 SCSI<=>ST506 converter and a Seagate ST-238 hard disk, all in an IBM clone cabinet. It works fine. I have a few questions concerning future expansion: 1) The Adaptec 4070 can handle two disks. Do they appear as SCSI devices 0 and 1, or are they presented as one large disk? 2) How does SCSI daisy chaining work? Are all 50 pins (or 25 MacPins) just hooked up in parallel? 3) Does the Supra memory expansion still exist or is it a victim of the 256K DRAM "shortage"? None of the dealers seem to have it in stock. Thanks in advance, Jim Cronin
billsey@agora.UUCP (Bill Seymour) (05/17/88)
From article <7200@rama.UUCP>, by jdc@rama.UUCP (James D. Cronin): > > I recently went the homebrew route for a hard disk - Supra SCSI > interface, Ataptec 4070 SCSI<=>ST506 converter and a Seagate ST-238 > hard disk, all in an IBM clone cabinet. It works fine. > I have a few questions concerning future expansion: > > 1) The Adaptec 4070 can handle two disks. Do they appear as SCSI > devices 0 and 1, or are they presented as one large disk? They will appear as device 0, LUN 0 and device 0, LUN 1. When you partition them, they will come up as DH0: (1|2|3|4) and DH5: (6|7|8|9). > > 2) How does SCSI daisy chaining work? Are all 50 pins (or 25 MacPins) > just hooked up in parallel? Yup, just hook them up in parallel. What I've done is make a short 50 pin cable that has several male connectors on it. That way I can hook several drives/computers up easily. (I currently have two drive and two Amigas hooked to my system.) > > 3) Does the Supra memory expansion still exist or is it a victim of > the 256K DRAM "shortage"? None of the dealers seem to have it in > stock. The shortage may have something to do with it, but more likely it has been noise on the ground/power traces. They were trying to do it with a two layer board and weren't having much success. I do know they will sell you one, but you may have to send your interface in and have them install/test it. That's the only way they can be sure to have it work. They only have the one meg expansion out for the 1000, one and two megs are available (sort of) for the 500... > > Thanks in advance, > Jim Cronin