Re: Re[2]: GREAT NEWS! ! ! !

From: Jo Even Skarstein <>
Date: Fri, 12 Sep 1997 16:59:26 +0200

On 12 Sep 1997 wrote:

> The biggest problem is that we need to initialise both processors,
> which actually means two boots! If we could control the 030's reset
> signal and control the address from which it boots, then it all would
> be much easier. But we'll see what I can do...

This is what the Atari Compendium says about this:

"Upon a cold or warm boot, microprocessors in the 680x0 series load
the initial supervisor stack pointer from the first longword in memory
($0) and begin execution at the PC found in the second longword ($4).
The location this points to is the base initialization point for Atari

If it was possible to change these values things would be very easy:
Boot the 040, change $0 and $4 and allow the 030 to use ST-RAM when
the ST-bus is idle. But since the two first longwords in memory are
located in ROM, we can't just change these. $4 also points to ROM so
it's impossible to change the actual boot-code :-(

I guess the only realistic way to work around this is to patch the

To actually *use* the 030 we could add another Pexec() which
explicitly loads a binary to ST-ram and initialises the 030. With MiNT
then *true* multiprocessing should be possible :-)

** Jo Even Skarstein
** beer - maria mckee - atari falcon - babylon 5
Received on fr. sep. 12 1997 - 16:59:26 CEST

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