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Re: Setup for MFM 5 1/4" DD 360K

Posted: Sun Nov 21, 2021 10:00 pm
by Guld
brightcaster wrote: Sun Nov 21, 2021 9:08 pm This is in deed a very poor signal quality! Is the terminator plugged in? (Look at page 20/21 of the manual for function and position on the PCB.) Was it the only drive in the original machine you tested it with or was there a second drive connected?

Otherwise I could only think of a EMC problem at the moment. Do you feed the drive with a separate power supply which is not connected to anything else but mains and the drive itself? Does the power supply have a ground connection, which leads to a "ground loop" to your PC?

David
Hmmm...interesting. No, the terminator is not installed in slot RN1 on either of the 2 drives I own. The system I used it on it only designed for a single drive so that's all it can handle and I've had this drive since the computer was new so I can guarantee this is how it came installed.

Does that mean it needs to be installed to use it with the Kryoflux and apparently not installed to use it on the actual system? I wouldn't even have any clue where to find one for it unless it's a common thing on Digikey etc. It appears to be a 14 pin slot (not 16 weird).

Or possibly connect it to the second drive connector on the Kryoflux and put a terminated drive (e.g. the Teac) on the end of the connector?

Re: Setup for MFM 5 1/4" DD 360K

Posted: Mon Nov 22, 2021 1:47 am
by SomeGuy
In practice if the cable is short, lack of termination should not cause a major problem, but that may not always be the case. I've had at least one drive act oddly without termination.

"Resistor Networks" are very common and can be found at various parts places. according to the manual, it takes a 150 ohm dual inline pin resistor network. You could also just use a handful of 150 ohm resistors.

Yes, attaching it as a second drive with a terminated drive as primary would also satisfy the termination electrical requirements.