MFM or ESDI QBUS controller for one PDP-11/23 PLUS
Jerome H. Fine
jhfinedp3k at compsys.to
Tue Oct 9 07:51:06 CDT 2007
>Sergio Pedraja wrote:
>I'm perplexed. The RQDXn controllers are MFM and Floppy. Best shot
>>is late firmware RQDX3 as it does RX33 and most all MFM drives. Its
>>also easier to find.
>At least as I can remember, the RQDx3 needs an internal distribution panel.
>I'm searching for ONE single board.
Jerome Fine replies:
Then perhaps you can describe your other hardware - backplane
with power supply. Do you have a BA23 or a BA11 box? Or
something else? What about the serial ports, etc.?
I agree that the RQDX1, RQDX2 and RQDX3 require a distribution
panel of some sort to change from the 50 pin cable to the
34 pin / 20 pin cable required by MFM hard drives and floppy
drives. That panel is usually part of a BA23 box. A BA123 box
uses a distribution board which can handle 4 drives, but the
hard drives also require an additional READY / WRITE PROTECT
(very small) panel.
As far as I can remember, the only controller that I have
ever used with an RX33 was a DEC "late firmware RQDX3" as
Allison has noted.
Probably a 3rd party controller like the Dilog DM01 is what
you are looking for. But I suspect that these days, an RQDX3
is probably more easily found - except for that internal
distribution panel which is also required if you are using
a BA11 box.
Let us know about your other hardware so that we can help a
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