[Coco] Prototype/Breakout Board

[Richard E. Crislip]

On Monday, March 26, 2012 02:20:48 PM John W. Linville wrote:
> On Mon, Mar 26, 2012 at 06:58:05PM +0100, Phill Harvey-Smith wrote:
> > On 26/03/2012 16:17, John W. Linville wrote:
> > >On Sat, Mar 24, 2012 at 11:32:35PM -0400, jdaggett at gate.net wrote:
> > >>Unidirectional Ouput from the Coco buss and microprocessor
> > >
> > >Someone did a project not too long ago that had an external CPU
> > >(maybe a Propeller?) driving the CoCo's video circuits and such.
> > >So, It seems like the address lines need to be bidirectional if you
> > >want something like that to work.
> > 
> > But to do this would you not need to be able to tri-state the bus ?
> > Unless you could just assert HALT and then drive the bus externally.
> 
> http://www.coco3.com/community/2011/06/prococo-cart-a-propeller-based-tandy
> radio-shack-color-computer-2-cartridge/
> 
> He asserted HALT and took over the system with the Propeller.
> 
> > Though admittedly that would not be the normal way to use the bus.
> > 
> > BTW why do people seem to spell bus as buss, is this a US / UK
> > English thing ? I perticually notice it on this list which has a
> > large number of members in the US.
> 
> Beats me -- FWIW, ISTRC seeing the "buss" spelling on a number of
> 80's era schematics for computers and arcade machines.
> 
> John

I alway though "bus" was something you rode in and "buss" was a circut.