Re: self test mode

[ntohsepuasmch@centurytel.net (Theusch Family)]

On Tue, 06 Feb 2001 16:35:05 -0600, Dennis Jenkins <dennis@usb.com>
wrote:

>	One of the recent posts brought up a question that I've had for years: 
>When you do a control-closed apple-reset, the machine does a self test. 
>Where in the ROM is the code that does this?  I assume that is is
>'hidden' in the cxxx area, normally switched out.  Where in the f8xx ROM
>space is the code that gets called by the IRQ/NMI/whatever when you
>press those keys?  I assume that the f8xx code calls the cxxx code. 
>This is based upon a brief one liner that I read in a post here a few
>weeks ago.
>
>	Anyway, can someone explain how the computer gets into the self test
>mode, and how one could possible trigger this programmatically (not that
>I would ever do so in production code).
>
>-- 
>dennis@usb.com                           Universal Savings Bank.
>
>The three most dangerous things are a programmer with a soldering
>iron, a manager who codes, and a user who gets ideas.


It is somewhere in the range of c000-cfff.  Normally expansion card
ROM is in this area but writing the soft switch at INTCXROM (c007)
will switch to the diagnostic ROM.

<plagarise>

In the original //e it is in $C400..$C7ff. Entry at $C401.
In the enhanced //e it gets shorter. $C600..$C700.

[If you have an enhance //e]
eg:
	sta	$c007
	jmp	$c401

</plagarise>

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