[stella] Stella sequencing

Subject: [stella] Stella sequencing
From: John Harvey <jkharvey@xxxxxxxxxxxxxxxxx>
Date: Sun, 03 Jan 1999 23:51:36 -0600
Note: I could be wrong about some of this.  If so, please correct me.

An interesting thought entered my mind when writing some code yesterday.
Basically, I was writing a subroutine within a subroutine (JSR's) and it
compiled and actually ran on the PCAE emulator.  I was under the impression
that in the event of a subroutine, the return address of the subroutine is
saved in the program counter (I could be wrong, I read this a while ago),
until the event of an RTS.  Is this just a fluke?  There is no system stack
that I know of, unless, $FF thu $80 are automatically called, and the stack
pointer incremented, but I do not think this is so.  If it is possible to
have a nested loop, what is the limit?  I see that branching inside of a
subroutine is not a problem, but if there were enough nested JSR's and
RTS's on the'r own, would the program get confused and ignore the command,
or keep going, somehow finding the corresponding JSR?

Also, (if anyone knows), does an emulator "fix" programming mistakes?  Are
there things that I could program on an emulator that would not work on a
real VCS?  I already know of a few bugs with joystick input that can occur.
 Any big ones out there?

Sorry if I have asked a lot of questions, but it is hard to find the
answers by using conventional means.  I hope to help other rookies on the
list in the future, but as of now, it seems that I am one of the "young
'uns" on the list, as my knowledge is not yet so immense.  Thank you to all
for putting up with me.

-John K. Harvey

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