Home Forums General Discussion TM drive connections

This topic contains 5 replies, has 5 voices, and was last updated by  Richard 2 years, 3 months ago.

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    This really doesn’t fit anywhere because it is just a curiosity. I noticed the connection scheme for the TM to the drives makes no sense to me. As I noticed there are two SCSI connectors and you must use both I had assumed that one was video drives and one audio (logical assumption I think). Once I got into the install instructions I saw that 1 video and audio share one cable and the other video drive shares te other. I am really curious as to the logic to this as doing it the other way might allow more drives in my logic (all video on one channel and all audio on the other). Please post or PM me with a simple or complex answer because I am dying to know why it was configured this particular way.



    My guess is the ammount of data needing to be transfered for video. Perhaps the controller cant handle 2 streams of video at once… so you need to have them split up.

    But that’s just a guess.



    Just upgraded my TM drives this past week to 73 gb. Checked with Support and was told that TM currently only supports (1) Volume (2 video/1 audio). The SCSI chain is designed to write across the 2 video drives as a “raid”. The audio drive can share SCSI with (1) video because they don’t write concurrently. If you do work with these drives, beware of the instructions in the manual. There are several typos which detail which drive configures to which cable and which are the audio and video ID’s. Go with the pictures. The text will confuse you, well it did me.

    Good Luck!



    Jake and rztv are correct. We split the video drives onto their separate SCSI channels because of the bandwidth required by video. Essentially, with the interlaced nature of video, one field goes to one drive, the other field goes to the other drive. The separate SCSI channels allow the drives to be accessed independantly. Since audio doesn’t require much bandwidth, it can share one of the channels with a video drive.



    Ahh, so there is logic to it. I thought some deranged mad scientist developer just made it up as he went. The bandwidth part makes some sense. I am assuming the hardware is pre SCSI 160/320 data rate or that might have helped some. Is the bandwidth part the reason we can’t add more volumes? Also, is anyone (currently) actually working on being able to install more drives? I’m not sure how that’d work with the funky drive carrier. I was actually hoping it would be setup for 5.25 mounting instead of 3.5. That would allow removable drive carts to be used and allow volume swapping for extended storage. I was hoping to try that out until I saw the mounting frame. I’m looking at trying it anyway. I have some spare parts around and might be able to rip out an old 5.25 mounting bay and set it in the case. Setting up another fan is easy since they make stuff for mounting to drive bays. We currently have plenty of empty Ultra SCSI carts I just need the mounting frames. If it works I’ll post for everyone.



    The bottom part of the box (Studio version) fits into the same description as the whole universe: ‘ it is awful waste of space’! If I had designed the drive bay & fan assembly, I would have returned my paycheck for that month….
    Swappable drives in brackets would be a good improvement: good guality drive brackets are equipped with fans and the ventilation problem would be solved by that. There is so much room in the back part of the box that a complete computer could be fitted in there ( which may have been in plans by the time of Adam & Eve/Kiki)! This can be done quite easily even today, by using some special designs like those in IBUS rack PC product line.

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