krivulak
New Member
Hello, I just aqurred an OMTI 5520 MFM controller with Seagate ST-124 and I basically don't know, what i have to do with that to make it work. Main point is that I don't know, how to power it. Thanks for reply!
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Powering OMTI 5520 MFM controller
- Thread starter krivulak
- Start date
Apparently, power is supplied through connector J4 (diagram). I couldn't find the pinout in the docs, even looking at the docs for the earlier OMTI 5510 (which didn't have a separate power connector). So I guess you'll have to ring it out (e.g. with an ohm meter). Hopefully there is a non-custom chip you can identify to find +5V power and ground on the board. Maybe the power pins even connect to the edge connector which would make them easy to identify. Or maybe somebody else has more info, or an original power cable that could be documented for you. Good luck.
Chuck(G)
25k Member
J4 is there for applications where the 5520 and the ST124 are mounted to the same plate to form a "hard card" type of assembly, so the drive gets power from the ISA card. To be very clear--you do not supply power to the controller to J4, but extract power from the ISA bus to power the drive via J4.
If that's not your case (i.e. the ST124 is separated from the controller), just use the J3 connector at the corner of the drive. photo here and ignore J4 on the controller.
If that's not your case (i.e. the ST124 is separated from the controller), just use the J3 connector at the corner of the drive. photo here and ignore J4 on the controller.
krivulak
New Member
I have exactly this (I forgot to say my primary language is not english, but czech 
). On top left corner you can see it.
OK, now I know, that I don't need that J4, because it is standard controller with hdd on cables. And now my second problem, can I use it in newer PC? (like 386/486), or I have to use it in my only XT pc, Commodore PC20-III (for which I don't have keyboard)?
). On top left corner you can see it. OK, now I know, that I don't need that J4, because it is standard controller with hdd on cables. And now my second problem, can I use it in newer PC? (like 386/486), or I have to use it in my only XT pc, Commodore PC20-III (for which I don't have keyboard)?