[Coco] Pop PC with empty stack?

[Lothan]

From: "Gene Heskett" <gene.heskett at verizon.net>
Sent: Tuesday, April 06, 2010 10:37 AM
To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
Subject: Re: [Coco] Pop PC with empty stack?

> No, that is the shorthand way to do an RTS, saving an instruction fetch
> cycle in the process.  The stack, in general, is never 'empty' and the 
> last
> 2 bytes that will fetch to the pc are the return address that it got there
> from.

I knew about PULS PC being basically the same as an RTS, but it had me 
confused because I couldn't find a BSR or LBSR in the chain leading to that 
label. I finally found an LBSR in the chain this morning after I got some 
sleep last night. It's just not such a straight-forward LBSR -> label, blah 
blah, RTS. It's more like LBSR -> label, branch and conditional branch 
several times, and the RTS is in a conditional branch at the end of the 
module.