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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Kernel on May 16, 2011, 10:17:21 PM

Title: SCSI Compatability
Post by: Kernel on May 16, 2011, 10:17:21 PM
Ok, may be a dumb question but I'm leaving work and don't have time to searh Google right now :)  I did a little but couldn't find an answer yet...

On an A3000, can SCSI-2 and U320 drives be used with the internal controller using a 68 to 50 pin adapter?
Title: Re: SCSI Compatability
Post by: TheGoose on May 16, 2011, 11:10:42 PM
Quote from: Kernel;638233
Ok, may be a dumb question but I'm leaving work and don't have time to searh Google right now :)  I did a little but couldn't find an answer yet...

On an A3000, can SCSI-2 and U320 drives be used with the internal controller using a 68 to 50 pin adapter?


Yeah, get right adapter and termination right. I have done this.
Title: Re: SCSI Compatability
Post by: Zac67 on May 16, 2011, 11:32:39 PM
Yes, SCSI devices are downwards compatible in general. However, LVD drives (U2W, U160, U320) have no termination options so you'll have to use a cable terminator or put them in the middle of the bus.
Title: Re: SCSI Compatability
Post by: Kernel on May 16, 2011, 11:35:06 PM
Wow, you guys just made my day!

Thanks!
Title: Re: SCSI Compatability
Post by: TheGoose on May 16, 2011, 11:41:12 PM
Quote from: Zac67;638246
Yes, SCSI devices are downwards compatible in general. However, LVD drives (U2W, U160, U320) have no termination options so you'll have to use a cable terminator or put them in the middle of the bus.


Good note here. I only could get things working with a stand alone terminator stuck at the end of the chain.
Title: Re: SCSI Compatability
Post by: Kernel on May 17, 2011, 01:54:37 AM
Ok, and one more thing... using stock AmigaOS 3.1, that is the maximum hard drive size and partition that the Amiga can handle?
Title: Re: SCSI Compatability
Post by: TheGoose on May 17, 2011, 02:40:33 AM
Quote from: Kernel;638267
Ok, and one more thing... using stock AmigaOS 3.1, that is the maximum hard drive size and partition that the Amiga can handle?

You should make your boot partition just under 2GB. Other partitions can go up to 4GB, this is with plain old AOS 3.1
Title: Re: SCSI Compatability
Post by: SACC-guy on May 17, 2011, 08:32:07 AM
I always thought the limit for AOS 3.1was 2gig partitions, four gig per drive?
Michael
Title: Re: SCSI Compatability
Post by: Zac67 on May 17, 2011, 09:58:03 AM
http://www.youngmonkey.ca/nose/articles/NewTekniques_9810/AmigaInMotion.html (http://www.youngmonkey.ca/nose/articles/NewTekniques_9810/AmigaInMotion.html)
Title: Re: SCSI Compatability
Post by: Kernel on May 17, 2011, 12:26:09 PM
Wow, these are the reasons I should NEVER have given up on the Amiga... quick, direct, meaningful answers!
Title: Re: SCSI Compatability
Post by: Kernel on May 17, 2011, 05:05:23 PM
Ok, now that I have checked out that site...

Let's say I have come across a few 73.4GB U320 drives.  I'd like some opinions on how to proceed so that I don't end up with corruption once I've installed and started using everything.

Based on what was said here, the first thing I need to do is keep the WB partition under 2GB.  Is there a apecific reason for that or is it just preference?  The site referenced keeping the partition under 3.8 GB (or something close to that) to be safe.

As for the references to updated file systems like FFS in OS 3.5 that could access beyond the 4GB barrier, and the utilities NOT to use due to possible corruption when going this route, can anyone with experience in this realm (or alternatives) tell of their experiences and recommend a course of action and toolset?
Title: Re: SCSI Compatability
Post by: freqmax on May 17, 2011, 05:45:30 PM
The combination of 32-bit signed (http://lclevy.free.fr/adflib/adf_info.html#p6) block pointers and 512 bytes/block = 2 GB. Though be careful with using 0xFFFFFFFF as the number of blocks as it can mean -1 in signed interpretation. There are different saying if it's unsigned or signed. But the sure bet is to limit to 2 GB.

Thus to break the 2/4 GB wall. Use PFS (or SFS). Or even better network via Ethernet to a fileserver that can store at least 8 EBytes ;)

Maybe one can trick with block size larger than 512 bytes, but dunno if FFS supports that completely.
Title: Re: SCSI Compatability
Post by: Kernel on June 02, 2011, 04:13:40 AM
Quote from: TheGoose;638244
Yeah, get right adapter and termination right. I have done this.


Can you recommend model and place to purchase the terminator from?  I'm in the USA and I believe from another post I read that you are as well?

I ordered a SCSI 80 to 68/50 converter that was supposed to have termination on it but they sent me the wrong piece.  I emailed the merchant and have not received a response yet and their voicemail is "full".  I want to get a converter/termination board ASAP... was hoping to be loading this weekend.
Title: Re: SCSI Compatability
Post by: TheGoose on June 02, 2011, 03:31:03 PM
Quote from: Kernel;641831
Can you recommend model and place to purchase the terminator from?  I'm in the USA and I believe from another post I read that you are as well?

I ordered a SCSI 80 to 68/50 converter that was supposed to have termination on it but they sent me the wrong piece.  I emailed the merchant and have not received a response yet and their voicemail is "full".  I want to get a converter/termination board ASAP... was hoping to be loading this weekend.

There is a little shop in Raleigh NC that has forever had great merchandise and support for all things SCSI. And still do, was there 2 weeks back. Site is not great but you could call...

http://www.goconnect-it.com/

I'll need to look at the thingamajigs I have I'll post what I have / worked tonight...