Subject: Re: EAE SAM instruction

From: [email-masked] (Bob Supnik)
Date: 6 MAR 94 22:44:06

>[email-masked] asked
>How do DCM and DPIC behave if the SWP is not included with them?

1. DCM...  
   a	L'AC = AC ^ 07777 + 1, the link is unconditionally loaded
   b	Swap AC and MQ
   c	L'AC = AC ^ 07777 + carry in = Link from step a

net:	MQ = - AC
	L'AC = ~(old MQ) + (new MQ == 0)

2. DPIC...  
   a	L'AC = AC + 1, the link is unconditionally loaded
   b	Swap AC and MQ
   c	L'AC = AC + carry in = Link from step a

net:	MQ = AC + 1
	L'AC = old MQ + (new MQ == 0)

The little chromium switch is from the beginning of the Firesign Theatre's
"Don't Crush That Dwarf, Hand Me The Plyers"

Bob Supnik	>[email-masked]
		>All opinions expressed are those of a hardline microcoder
		>and do not reflect those of Digital Equipment Corporation