[Coco] CoCo3 and 16K cart roms.....

[Barry Nelson]

 To access the contents of $E000-$FE00 in rom on a CoCo 3 you must first set ROM mode.

        		LDA	$FFFE		Get first byte of the reset vector
        		CMPA	#$8C		Is this a CoCo 3?
        		BNE	COCO12
			CLR	$FFDE		Enable ROM in memory map
COCO12	JSR		ADDRESS	Your routine in upper rom
        		LDA	$FFFE		Get first byte of the reset vector
        		CMPA	#$8C		Is this a CoCo 3?
        		BNE	SKIPRAM
			CLR	$FFDF		Enable all RAM mode
SKIPRAM	NOP				Code continues

> Bill Pierce ooogalapasooo at aol.com 
> Mon Apr 11 09:02:46 EDT 2016
> 
> Phil, isn't that where Super Extended Basic is at?
> The Coco 3 transfers it's Roms to ram to patch in SECB after boot, so your rom is being over written by SECB. That's the same problem with extending HDBDOS to 16k, it won't work on Coco 3 without doing some bank switching to keep SECB working.