Hello! silverdr@wfmh.org.pl wrote: > There are two problems with the above - first I was looking at the wrong page of the schematics - so the above should read U3 rather than U1, be then this doesn't seem to be valid either as U3 on your board is a small PAL chip rather than the FDC in question. That's why I put a "valid" qualifier before the "schematics" in my first post referring to the schematics. I /guess/ it's the U22 on your board. It's called U3 on the schematic, but it's the schematic for rev. 2A. On our rev. 2B boards this is U22. Please also note that U22 does not drive the RDATA signal. The currently selected disk drive is driving this signal. The problem arises because this line is shared among all drives so it is directly exposed on the connector. Actually, now that I look at the schematic, I see that this line is pulled up with 470 Ohm resistor. Quite possibly, the output from the drive is open collector and needs such pullup, which is too weak compared to the capacitance of the cable. All the other lines on the connector are driven directly by U22 and they do not exhibit this problem. Regards, Michau. Message was sent through the cbm-hackers mailing listReceived on 2016-03-04 11:00:11
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