Amiga.org

Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Gulliver on September 16, 2010, 01:45:00 AM

Title: Can I use a wide scsi drive on a narrow scsi bus?
Post by: Gulliver on September 16, 2010, 01:45:00 AM: Can I use wide scsi drive on a narrow scsi bus?
I want to connect my BlizzardPPC 603e+ to an ACARD AEC-7720UW plugged to an IDE drive. Is it possible to do it only by using a 68 to 50 pin male to male adapter?

Thanks in advance
Title: Re: Can I use a wide scsi drive on a narrow scsi bus?
Post by: ElPolloDiabl on September 16, 2010, 02:02:04 AM: No. You can use different speed SCSI though.
Title: Re: Can I use a wide scsi drive on a narrow scsi bus?
Post by: tone007 on September 16, 2010, 02:38:36 AM: UW-SCSI devices can generally be used on old 50-pin SCSI interfaces with the proper adapters, but I've never seen it tried with one of these ACARD devices. I'd give it a shot if I had one lying around.
Title: Re: Can I use a wide scsi drive on a narrow scsi bus?
Post by: HammerD on September 16, 2010, 03:04:34 AM: Quote from: tone007;579654
UW-SCSI devices can generally be used on old 50-pin SCSI interfaces with the proper adapters, but I've never seen it tried with one of these ACARD devices. I'd give it a shot if I had one lying around.

Connected to my Cyberstorm PPC SCSI is:

IDE DRIVE connected to ACARD 7720UW (terminated) --> Yamaha 50 PIN SCSI CDRW with (68-50 pin adapter) --> CS PPC SCSI <-- Active Terminator.

At least that configuration works.
Title: Re: Can I use a wide scsi drive on a narrow scsi bus?
Post by: Gulliver on September 16, 2010, 04:06:57 AM: @HammerD

So you terminate both the ACARD (the Acard has built-in terminator?) and then at the other end of the scsi chain with a scsi active terminator.
Is this correct?
Title: Re: Can I use a wide scsi drive on a narrow scsi bus?
Post by: Damion on September 16, 2010, 05:07:05 AM: Quote from: Gulliver;579661
@HammerD

So you terminate both the ACARD (the Acard has built-in terminator?) and then at the other end of the scsi chain with a scsi active terminator.
Is this correct?

Exactly. Both jumpers on the Acard closed (termination and term power) and you should (theoretically) be set.
Title: Re: Can I use a wide scsi drive on a narrow scsi bus?
Post by: Gulliver on September 16, 2010, 05:22:14 AM: Thank you!
Title: Re: Can I use a wide scsi drive on a narrow scsi bus?
Post by: Zac67 on September 16, 2010, 07:35:42 AM: Some wide devices require proper termination of the whole bus, which the narrow bus half is just terminating on the low byte - thus you need a 'half terminator' (often seen with SCA adapters) if the drive doesn't work right away. But most do.
If the ACARD has built-in termination it'll take care of that but needs to be at the end of the bus.
Title: Re: Can I use a wide scsi drive on a narrow scsi bus?
Post by: Bamiga2002 on September 16, 2010, 08:15:09 AM: I'm using the same ACard on my BPPC scsi and an IDE drive, works good. The BPPC scsi just limits the HD speed but it's still fast enough for me.