AMD bit-slice machines

woodelf bfranchuk at
Mon Jan 2 01:04:58 CST 2006

William Maddox wrote:

> For easy-to-decode, I can't think of anything that gives you as much 
> power for as little work as the DG Nova.  The Nova encoding, however, 
> is very closely tied to a model datapath, as the arithmetic, logical, 
> and shift instructions are encoded like the so-called 
> "microinstructions" of the PDP-8.  Most bits in the instruction 
> correspond directly to control signals without any encoding at all.  
> On the other hand, the Nova datapath is relatively straightforward to 
> implement in TTL.
But looking at the schematics it also makes full use of 74172's , 8 x 2 
dual port ram.
In fact someone sent me some 74172's but they got lost in the mail. :(
The lack of real hardware like TTY's and Core memory made up of so much 
of  the early
processors I/O that a full emulation is not possible. Lack of full 
documention is the other
problem. My pdp-8 handbook covers TAD quite well, extended options for 
multiply , or divide it does not. I could cheat and see what Simh does. :)

> --Bill

Ben alias Woodelf
PS. Since CPLD's now are 3.3 volts I can use ferro-ram memory after 
getting a design
working @ 5 volts and standard memory.

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