[Coco] CoCo 3 patch question

[Robert Gault]

OK, I think I know what is going wrong although it just does not seem 
right based on the Spectral Associates info.

Roger, try the following code assembled as an 8K ROM named disk11.rom. 
Put that in the MESS coco3 or coco3h ROM directory and see what happens.

	org	$c000
	fcc	/DK/
	bra	$c00c
	rzb	$c00c-*
	org	$c00c
start	lda	#%11001100
	sta	$ff90
	sta	$ffde
	leax	mesg1-1,pcr
	jsr	$b99c
	jmp	$a0e2
mesg1	fcc	/THIS IS A TEST/
	fcb	0
	end

Running a test with the MESS debugger, I found initially that when sta 
$FFDE took place the Coco3 32K internal ROM was switched in. In the 
above code, switching to 16K internal, 16K external is crucial.