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UDA 50 SDI pinout

NeXT

NeXT

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I'm stopping mid-project my cabling scheme and switching to something even better. Between both projects though I still need the pinout for the SDI harness connector on board M7486 of the UDA 50 boardset. I checked both the owners and service manual on bitsavers and neither gave me what I needed.
 
Do you mean the wiring scheme from the header connector on the controller board to the four SDI plugs on the other end? I could check one of those 4-way cables with a meter.
 
The header connection on the controller. I'm missing everything between that and the drive.

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UDA.jpg
 
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Lou has written a nice article / thread about his SDI adventures. [He changed over to UTP] It's here on the forums somewhere.
 
gslick said:
How about the pinout of P4 on page 43 of the UDA50 print set:

http://www.bitsavers.org/pdf/dec/disc/uda50/MP01331_UDA50_EngrDrws.pdf

The P4 signals are labeled XWCD H/L, XRTCS H/L, XRRD H/L XRTDS H/L.

My guess is that those map 1:1 in the same order as the WRT/CMD DATA +/-, CONTROL IN +/-, RD/RES DATA +/-, and CONTROL OUT +/- and repeated 4 times for the 4 ports.
Click to expand...

I forgot about that. Uhm, that looks to be about right and thus:

Code: 
17 - B1
18 - B2
19 - B3
20 - B4
21 - B5
22 - B6
23 - B7
24 - B8
25 - A1
26 - A2
27 - A3
28 - A4
29 - A5
30 - A6
31 - A7
32 - A8
However if someone could double check that with a DMM it would be appreciated.
I'm trying to replace the UTP idea. It just seems way too scary for me and I'm assuming DEC went with coax for a reason. I'm going to try with SATA/ESATA cables instead because it's so similar to SDI cables and requires a lot less work to build the harness. I'll make a thread soon to talk more about this. I can't really upload photos anyways when my system is in the middle of a backup.
 
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What is the impedance of SATA cable? Cat 5 ethernet cable at about 100 ohms was quite close to the 93 ohm cable used for SDI. I have run 50 foot lengths of CAT 5 cable with SDI with no problems.

I am very interested to hear about how to prepare the ends of the SATA cable to work with the Berg headers on the U/KDA50 and on the SDI drives. Are the pins on SATA cables on 0.1" centers? It would be great if SATA cables can be used with minimal additional effort.

I am away on business at the moment, and not near my notebooks. I was able to figure the pinouts from the UDA50 and RA80 print sets. Also, you might be able to figure out enough by looking at the photos I posted in the album about home made SDI cables.

Lou
 
Holy moly you put a lot of work into that! I'm sorry it didn't work out. So much for SATA cables. We all know now that they have a common shield among the little coaxes. Sorry you found out for us the hard way. When I'm in uncharted waters, I usually just jerry-rig the arrangement. If it works out, then I do all the beautification.

For reference, my earlier thread on home made SDI cables is here: http://www.vintage-computer.com/vcforum/showthread.php?18049-DIY-SDI-Cables

Interestingly I mentioned directly in the fifth post that the four little coaxes must be kept electrically isolated.

In the 12th post I provided the pinout of the cable from the U/KDA50 end to the drive end.

I'm sorry I didn't remember all this earlier. There have been too many projects since then....

Lou
 
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