[Coco] M.E.S.S. 6309 error

[Robert Gault]

As Rodney mentioned, you need to use the same register. However, there 
still seems to be a bug in MESS as I can't get another of these bit 
operations to work. For example,

	org	$6300
start	lda	#$70
	tfr	a,dp
	clr	$7034
	ldb	#$80
	stbt	#%10111111 $34	EDT6309 notation
*       stbt    b, 7, 7, <$34	CCASM notation
	swi
	end

When the above is run in EDT6309 and memory at $7034 examined, the 
results are different between a real Coco and MESS. MESS does not change 
the byte in memory but a 6309 Coco does.

Roger Taylor wrote:
> The LDBT and STBT instructions in the COCO3H mode of M.E.S.S. are broken.
> 
> The following program should take the value poked at <255, read the 7th 
> bit, store that bit into the 7th bit of register A, then store register 
> A to the screen at 1024.
> 
> LOADM this program, POKE a 255 into address 255, type EXEC and then do a 
> PEEK(1024) to see the results.  Bit 7 of [1024] should be a 1 since the 
> value at 255 is all 1's.  I've tried many other combos and nothing seems 
> to work or give a clue to what M.E.S.S. is doing.
> 
>     org    3584
> start    clra
>     clrb
>     ldbt    a,7,7,<255
>     stb    1024
>     rts
>     end    start
> 
>