PDP-8 Disk Drive question

[Ethan Dicks]

On 7/29/05, Joe R. <rigdonj at cfl.rr.com> wrote:
>    Does anyone know if the M8357 (the RX-01 controller for the PDP-8) will
> work with the DSD-440 drives?  Someone here needs to read some RX-01 disks
> on a PDP-8 >>>ASAP<<< and they think that this combination will work but I
> don't think so. I have a good DSD-440 drive system but I don't have the DSD
> controller for the PDP-8. I also have a M8357 but no RX-01 drive system!

>From memory, the DSD interface is 26-pins.  The RX01/RX02 interface is
40 pins.  Beyond simple wire count, AFAIK, the interfaces are entirely
different.  In each case there is a semi-intellegent drive attached to
a fairly dumb host controller, but there was no attempt on the part of
DSD to imitate the DEC controller-to-drive protocol.

The DSD interface _is_ register-level compatible, but everything in
the middle is unique to each brand of drive system.

-ethan