Ideas for a simple, but somewhat extendable computer bus

[Jules Richardson]

On 11/17/2017 07:11 PM, Jim Brain via cctalk wrote:
> I looked at home computer busses (Atari, Apple, Commodore, Tandy, TI) for a
> bit of inspiration, but they all seem overly simplistic (not horrible, but
> hate to just punt on the idea).

Is the multi-CPU stuff important initially? If not then maybe keep things 
simple, but reserve a chunk of pins for "future expansion" with that in 
mind (or take the approach of various manufacturers and run the 'extra' 
stuff through to the boards separately from the backplane as/when it became 
necessary)

Alternately, STE immediately sprang to mind (it's 8 bit, but plenty of 
boards using 16 bit CPUs existed so long as they could handle data 8 bits 
at a time). Hazy memory is telling me there's some issue with 6502 CPUs, 
but pretty much any other 8-bitter (as well as m68k, ns32k etc.) is fair 
game. You could homebrew your own boards then, but also make use of all the 
hundreds of different commercial ones which existed.

If I remember right STE was essentially a simplified version of VME though, 
so that's probably worth a look too (I think someone else already mentioned 
it) - presumably there's more complexity and cost involved.

cheers

Jules