Re: Are old SCSI tape drives not all created equal?

On 08/26/2016 09:48 AM, j...@cimmeri.com wrote: > There appear to be different kinds of material used for the rollers. > For instance, with a 1999 OnStream DI30 (parallel port 30gb) ADR > drive, it's a typical black rubber roller like you'd see in many QIC > drives, and it's turned completely to

Re: Are old SCSI tape drives not all created equal?

On 8/21/2016 6:47 PM, Chuck Guzis wrote: On 08/21/2016 04:15 PM, Al Kossow wrote: nope, the transport has rubber rollers that crack, and little rubber belts. That's the transport; but what are the shortcomings of the medium itself? FWIW, I've got at least one DDS drive with rubber parts

Re: Are old SCSI tape drives not all created equal?

On 08/21/2016 05:49 PM, Al Kossow wrote: > I know it's true for the full height. I've had dozens of dead ones > because of that. I just picked up an 8705 yesterday, will open it up > and also check a 8505 > > Chuck, I've not had many problems with Exabyte media. DAT on the > other hand has been

Re: Are old SCSI tape drives not all created equal?

I know it's true for the full height. I've had dozens of dead ones because of that. I just picked up an 8705 yesterday, will open it up and also check a 8505 Chuck, I've not had many problems with Exabyte media. DAT on the other hand has been problematic. I just got a box of 8mm unix backups

Re: Are old SCSI tape drives not all created equal?

On 08/21/2016 07:27 PM, j...@cimmeri.com wrote: On 8/21/2016 6:15 PM, Al Kossow wrote: On 8/21/16 4:08 PM, Chuck Guzis wrote: 8mm (Exabyte) drives have a pretty good chance of survival nope, the transport has rubber rollers that crack, and little rubber belts. Al, Is that true for both

Re: Are old SCSI tape drives not all created equal?

On 8/21/2016 6:15 PM, Al Kossow wrote: On 8/21/16 4:08 PM, Chuck Guzis wrote: 8mm (Exabyte) drives have a pretty good chance of survival nope, the transport has rubber rollers that crack, and little rubber belts. Al, Is that true for both the full height and half height models? - John

Re: Are old SCSI tape drives not all created equal?

On 08/21/2016 04:15 PM, Al Kossow wrote: > nope, the transport has rubber rollers that crack, and little rubber > belts. That's the transport; but what are the shortcomings of the medium itself? FWIW, I've got at least one DDS drive with rubber parts that have turned to goo. --Chuck

Re: Are old SCSI tape drives not all created equal?

- Original Message - From: <j...@cimmeri.com> To: <gene...@classiccmp.org>; "discuss...@classiccmp.org:On-Topic and Off-Topic Posts" <cctalk@classiccmp.org> Sent: Sunday, August 21, 2016 4:04 PM Subject: Re: Are old SCSI tape drives not all created equal?

Re: Are old SCSI tape drives not all created equal?

On 8/21/16 4:08 PM, Chuck Guzis wrote: > 8mm > (Exabyte) drives have a pretty good chance of survival nope, the transport has rubber rollers that crack, and little rubber belts.

Re: Are old SCSI tape drives not all created equal?

On 08/21/2016 01:13 PM, j...@cimmeri.com wrote: > I agree wholeheartedly with your assessment. I do have a variety of > 4mm, 8mm, and DLT tape drives in addition to the problematic ones > discussed earlier. But trying other, novel mechanisms that contain > brilliant design ideas is quite a bit

Re: Are old SCSI tape drives not all created equal?

On 8/21/2016 12:46 PM, Chuck Guzis wrote: On 08/21/2016 10:12 AM, j...@cimmeri.com wrote: The final matter is that I'd still like to get the Teac to function with some software, just to watch it operate (you have to really like mechanical things to understand this strange fascination).

Re: Are old SCSI tape drives not all created equal?

com> To:<gene...@classiccmp.org>; "discuss...@classiccmp.org:On-Topic and Off-Topic Posts"<cctalk@classiccmp.org> Sent: Sunday, August 21, 2016 1:12 PM Subject: Re: Are old SCSI tape drives not all created equal? On 8/19/2016 1:08 PM, Chuck Guzis wrote: On 08/19/2016 09:2

Re: Are old SCSI tape drives not all created equal?

> On Aug 21, 2016, at 10:46, Chuck Guzis wrote: > One > advantage that DDS (and DLT...) has over most of the "QIC" tapes is that > they use a read-after-write system like the big 1/2" tape drives, making > a separate verification pass unnecessary. They also tend to follow the

Re: Are old SCSI tape drives not all created equal?

On 08/21/2016 10:12 AM, j...@cimmeri.com wrote: > The final matter is that I'd still like to get the Teac to function > with some software, just to watch it operate (you have to really > like mechanical things to understand this strange fascination). > Having put some time and $ into the Teac,

Re: Are old SCSI tape drives not all created equal?

What are you using to send/receive the commands? m - Original Message - From: <j...@cimmeri.com> To: <gene...@classiccmp.org>; "discuss...@classiccmp.org:On-Topic and Off-Topic Posts" <cctalk@classiccmp.org> Sent: Sunday, August 21, 2016 1:12 PM Subject:

Re: Are old SCSI tape drives not all created equal?

On 8/19/2016 1:08 PM, Chuck Guzis wrote: On 08/19/2016 09:24 AM, j...@cimmeri.com wrote: Where might I find information on how to form SCSI command data blocks so as to try the above commands? I sent just an "01" to the TEAC MT-2ST, and it did rewind.. John, what's your working OS

Re: Are old SCSI tape drives not all created equal?

On 08/19/2016 01:28 PM, j...@cimmeri.com wrote: > There were 2-3 versions. One was SCSI, the next QIC-02, and the > last, some raw interface called "BASIC."I've both a SCSI and a > QIC-02 version. That figures--they did a similar thing with the floppy drives--the Teac SCSI floppy is little

Re: Are old SCSI tape drives not all created equal?

Al, you don't happen to have this anywhere, do you? "Small Computer System Interface: An Overview and a Developer's Guide" Company:Digital Equipment Corporation Part: EK-SCSIS-DK -John On 8/19/2016 1:18 PM, Al Kossow wrote: apparently it isn't SCSI

Re: Are old SCSI tape drives not all created equal?

On 8/19/2016 2:16 PM, Chuck Guzis wrote: On 08/19/2016 11:18 AM, Al Kossow wrote: apparently it isn't SCSI http://oldcomputer.info/media/teac/index.htm But the product spec about says (top of PDF page 6): Interface: In compliance with SCSI ANSI X3.131-1986 ..and the remainder of the

Re: Are old SCSI tape drives not all created equal?

On 08/19/2016 11:18 AM, Al Kossow wrote: > apparently it isn't SCSI > > http://oldcomputer.info/media/teac/index.htm But the product spec about says (top of PDF page 6): Interface: In compliance with SCSI ANSI X3.131-1986 ..and the remainder of the document certainly would seem to imply SCSI,

Re: Are old SCSI tape drives not all created equal?

apparently it isn't SCSI http://oldcomputer.info/media/teac/index.htm On 8/19/16 11:08 AM, Chuck Guzis wrote: > On 08/19/2016 09:24 AM, j...@cimmeri.com wrote: > >> Where might I find information on how to form SCSI command data >> blocks so as to try the above commands? I sent just an "01"

Re: Are old SCSI tape drives not all created equal?

On 08/19/2016 09:24 AM, j...@cimmeri.com wrote: > Where might I find information on how to form SCSI command data > blocks so as to try the above commands? I sent just an "01" to the > TEAC MT-2ST, and it did rewind.. but did not react to any of the > other above commands just by sending single

Re: Are old SCSI tape drives not all created equal?

On 8/17/2016 6:17 PM, Chuck Guzis wrote: On 08/17/2016 02:59 PM, j...@cimmeri.com wrote: Hi, Chuck. Excellent question -- and they do respond per your minimum, but beyond that, I'm not sure. When a drive wouldn't work, I only thought to check for unit ready, unit identify, and to see what

Re: Are old SCSI tape drives not all created equal?

On 08/17/2016 01:07 PM, j...@cimmeri.com wrote: Hi, folks. I'm experimenting with various old SCSI tape drives to see which will work with my PDP-11/34 with an Emulex SCSI card. To my surprise, not all SCSI tape drives are created equal. Right, there was SCSI, SCSI-II and SCSI-III.

Re: Are old SCSI tape drives not all created equal?

On 08/17/2016 02:59 PM, j...@cimmeri.com wrote: > Hi, Chuck. Excellent question -- and they do respond per your > minimum, but beyond that, I'm not sure. When a drive wouldn't work, > I only thought to check for unit ready, unit identify, and to see > what would happen with a START or STOP unit

Re: Are old SCSI tape drives not all created equal?

On Wed, 2016-08-17 at 16:59 -0500, j...@cimmeri.com wrote: > Hi, Chuck. Excellent question -- and they do respond per your minimum, but > beyond that, I'm not sure. What device type do they report to IDENTIFY? There were some early tape drives which presented as direct-access (not

Re: Are old SCSI tape drives not all created equal?

On 8/17/2016 2:38 PM, Chuck Guzis wrote: On 08/17/2016 11:07 AM, j...@cimmeri.com wrote: I'm experimenting with various old SCSI tape drives to see which will work with my PDP-11/34 with an Emulex SCSI card. To my surprise, not all SCSI tape drives are created equal. I was under the

Re: Are old SCSI tape drives not all created equal?

On 2016-08-17 4:11 PM, Guy Sotomayor Jr wrote: On Aug 17, 2016, at 12:01 PM, Maciej W. Rozycki wrote: On Wed, 17 Aug 2016, Mouse wrote: SCSI is more than just the physical interface. Traditional SCSI is a parallel interface, with a bunch of signals and grounds. But,

Re: Are old SCSI tape drives not all created equal?

> On Aug 17, 2016, at 12:18 PM, Paul Koning wrote: > > >> On Aug 17, 2016, at 3:11 PM, Guy Sotomayor Jr wrote: >> >> ... >> If you *really* want to see how this was screwed up, take a look at >> Fibre Channel (which is basically SCSI over an

Re: Are old SCSI tape drives not all created equal?

Thanks very much, Mouse, Paul, Maciej, and Guy for helping me understand my SCSI tape drives. I had no idea! - John

Re: Are old SCSI tape drives not all created equal?

> On Aug 17, 2016, at 3:11 PM, Guy Sotomayor Jr wrote: > > ... > If you *really* want to see how this was screwed up, take a look at > Fibre Channel (which is basically SCSI over an optical Fibre network). > > While the commands are standard, you can’t really build a Fibre

Re: Are old SCSI tape drives not all created equal?

> On Aug 17, 2016, at 12:01 PM, Maciej W. Rozycki wrote: > > On Wed, 17 Aug 2016, Mouse wrote: > >> SCSI is more than just the physical interface. Traditional SCSI is a >> parallel interface, with a bunch of signals and grounds. But, layered >> atop the physical

Re: Are old SCSI tape drives not all created equal?

> On Aug 17, 2016, at 3:01 PM, Maciej W. Rozycki wrote: > > On Wed, 17 Aug 2016, Mouse wrote: > >> SCSI is more than just the physical interface. Traditional SCSI is a >> parallel interface, with a bunch of signals and grounds. But, layered >> atop the physical

Re: Are old SCSI tape drives not all created equal?

On Wed, 17 Aug 2016, Mouse wrote: > SCSI is more than just the physical interface. Traditional SCSI is a > parallel interface, with a bunch of signals and grounds. But, layered > atop the physical interface, there is also a command/response protocol > which is, strictly, independent of the

Re: Are old SCSI tape drives not all created equal?

> On Aug 17, 2016, at 2:07 PM, j...@cimmeri.com wrote: > > ... >Or maybe there were different > SCSI standards? Or is the standard simply imperfect? Yes. Among other things, SCSI is very peculiar in that it sends out many "draft" standards but allows devices to be built that "conform" to

Re: Are old SCSI tape drives not all created equal?

> To my surprise, not all SCSI tape drives are created equal. I was > under the mistaken assumption that all SCSI tape drives would pretty > much be abstracted the same way by the SCSI interface. That's the ideal. As you discovered, the world is far from ideal. > Question: So, even though some