home .. forth .. misc mail list archive ..

Re: My 2 cents on bootstrap loaders.


On Wed, 11 Jun 1997, Eddie Matejowsky wrote:

> >In http://www.dnai.com/~jfox/f21net.html  we read:
> >
> >---
> >At power-up, the processor is off, registers undefined. Setting sinking
> >receive will allow a message that sets a unique port address. A future
> >chip might power-up with receive on and default SOM, EOM and Address. This
> >would permit booting from the net.
> >---
> >
> >I think this solves the problem.
> >
> >--
> If it is implemented and it's relatively easy to interface to a pc then I'm
> quite happy with that. 

The network is a shift register.  If one uses a synchronous serial chip, one
can entirely control all bits in the stream and masquerade as another F21. 
If not, one can use one of the pins of the parallel port of the PC and bit
bang. 

> But I suspect you're interested in booting a network
> of f21s and I'm not (initially anyway). I want to be able to boot one f21
> from a pc. This is for two reasons one is software development and the
> other is field programming of embeded devices. 

Yep, both will work.  

If you come to think about it, you can plug a "serial card" your PC that
consists of an actual F21, that will drive the network for the other one
:-) 

> Also - I think the timer is definitely the way to go. With the speed of the
> f21 and the timer most of the fancy timer counter functions found in
> micro-controllers can be emulated, it seems like good ecomony to not have
> counter timer hardware being wasted when they're not used - things like
> PWM, event timers and waveform generators.

This is exactly what the analog coprocessor is all about, right :-)

> While I don't think the f21 is intended as a micro-controller I can see
> it's not too much of a jump to make it into one.

I don't see why not call it that way.  It is definitely micro, and it
definitely can control.

> Let's take over the world, one processor (core) that can power a toaster or
> a super-computer. I'm not sure if I'm joking or not :)

You'll be surprised when you learn that you're not :-)

--
Penio Penev <Penev@pisa.Rockefeller.edu> 1-212-327-7423