Adding floppy drives to my PDP-11?

Paul Birkel pbirkel at
Sun Apr 14 02:17:19 CDT 2019

>-----Original Message-----
>From: cctalk [mailto:cctalk-bounces at] On Behalf Of Glen Slick via cctalk
>Sent: Sunday, April 14, 2019 2:48 AM
>To: General Discussion: On-Topic and Off-Topic Posts
>Subject: Re: Adding floppy drives to my PDP-11?
>On Sat, Apr 13, 2019 at 3:07 PM Charles via cctalk
><cctalk at> wrote:
>> What about smaller drives (RX50? RX33?)... can those be interfaced to the
>> 11/23+ Qbus?
>Pick up a common as dirt M7555 RQDX3. If you don't have a BA23 with
>the built in distribution board for the M7555 RQDX3, then pick up an
>M9058 distribution board to break out the signals from the M7555
>For example, this one which is incorrectly listed as an M9056:

For more information and roll-your-own instructions, see:

Malcolm may still have PCBs available; shipping from Australia.


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