sm8000

Building my own external SCSI CD duplicator

Recommended Posts

I've recently acquired all the parts I need to build my own external CD burning tower. A case (or caddy?) with room for four drives, a few Plextor SCSI 40x UltraPlex Max CD-ROMs to choose from, and three Plextor SCSI 40x burners.

The case: eBay

I'm going to connect this machine to my system's LSI 20860, which has an external HD50 connector. The caddy itself has a pair of CN50 connectors on its back. I have a termination plug for the one not connected by the cable. The caddy itself has push-button ID settings on the back, and includes a 200 watt AT power supply.

Basically all I'm asking is whether I'm forgetting or missing anything, and for any insight you can give me into building and using this thing. All advice is appreciated!

Share this post


Link to post
Share on other sites

Ultra SCSI has a bandwidth of 20MB/s but your drives are 40MB/s total.

Three sets of IDE drives in double 5.25 1394 enclosures would work.

Share this post


Link to post
Share on other sites

No they're not. They're Ultra SCSI, 20MB/s drives. For that matter, the CD-ROM drive transmitting to burners A, B, and C at 6MB/s each (40x150KB/s) is under the Ultra SCSI limit.

Besides, I've already got the equipment. In fact I'm about to put it together and test it out, but I need to buy some blanks discs first.

Share this post


Link to post
Share on other sites

Like I said, you have a 20MB/s bus. With 3 ROMs and 3 burners that's 36MB/s. You need a AHA-3940 with two Ultra channels then.

Share this post


Link to post
Share on other sites

Yes, and he said it's a four drive chassis, so I'd think he'd be putting 1 reader and 3 writers in it rather than trying to jam 6 5.35" drives into a case designed for 4. Granted, Ultra SCSI would still be maxed out since it would be reading for 6mb off one drive and writing to 3 drives at 6mb each totalling 24mb/sec transfer which is just higher than the 20mb/sec available. Best bet would be to read from the reader to an image on a drive on another channel and then send to the 3 writers.

Share this post


Link to post
Share on other sites

Sorry I wasn't clear on that, I will only be using one CD-ROM drive, I just have to choose which one. So if the CD-ROM transfers to burners A, B, and C at 6MB/s each (when all disks are rotating at their max of 40x), then I should be just under the Ultra SCSI limit (at 18MB/s max. total). Is my thinking right there or am I way off base?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now