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Re: My 2 cents on bootstrap loaders.


At 08:25 PM 6/10/97 -0400, Penio Penev wrote:
>On Wed, 11 Jun 1997, Eddie Matejowsky wrote:
>
>> There has been a bit of talk here about putting a bootstrap loader into the
>> f21 on chip rom. I'm crossing my fingers really hard that this happens. 
>
>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. 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. I know this can be gotten
around in other ways but begin able to take a stock standard pc and plug it
would be very nice. Maybe I'm the odd one out in wanting this and I don't
expect Jeff and Chuck to do it on my account only. But Peter (I think) was
talking about a much larger bootstrap and I think a small one should be
considered. I don't know the relative dificulty of adding a bit more rom
compared to implimenting the booting from the network in hardware.
BTW I looked up the hc11 data and it's bootstrap rom is 192 bytes including
special mode interrupt vectors. The actual code is 128 bytes. It does have
use of on chip serial hardware but it's probably a reasonable ball park
figure.
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.
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.
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 :)
Cheers Eddie,
Edward Matejowsky - Queensland University of Technology (Brisbane, Australia)
personal home page at http://www.ozemail.com.au/~eddiema/index.html