DSD-440 and/or drive recommendation for PDP-8

[Allison]

>
>Subject: Re: DSD-440 and/or drive recommendation for PDP-8
>   From: "vrs" <vrs at msn.com>
>   Date: Sun, 19 Jun 2005 21:19:21 -0700
>     To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>> Even if you don't have an RX8E its a trivial board
>> easily copied.
>
>I don't know about trivial (I am trying to do one).  There are a lot of
>unobtainium parts in an RX8E that have to be designed out of a modern clone.
>(It's easily doable, but not trivial.)

Heres the trick.  Don't copy the parts, copy the logic and use 
standard TTL.  Most all the functions are easily available or 
or sometimes available in denser (newer relatively) parts. 
Trying to copy verbatim will be hard unless you have a lot of 
DEC junker cards to strip.  However most of the logical functions
are simple so substitutions are not as scary. 

Allison