Bug in 1581 ???

Hallo allemaal,
 
 
I was having a look at the source code of the 1581 to see if it is
possible to create 1581IDE, the IDE version of the 1581. And I ran in
this piece of code:
 
wdstatus				;
[CD42]
		php

		lda	WDSTAT	; get status
		lsr	a
		lsr	a
		lsr	a
		bcs	L93		; [1]

		and	#bit3+bit1+bit0
		tax

		plp			; restore carry
		lda	wdtrans,x
.by $2C
L93					;
[CD53]
		lda	#9
		sta	ContrStat

		lda	ContrStat
		rts


 This code checks the state of the WD177x. Have a look at the point
marked [1]. If the Carry is set for one or another reason, the branch is
taken. Then we end up at the RTS. But here it must go terribly wrong as
the state is still on the stack !!!
The basic of the source is the source uploaded by Dennis Jarvis. I had
to adjust it for my assembler but the comments are original. So IMHO the
"restore carry" would make sense if PHP had been placed after BCS.

Your comment please.


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