Re: [stella] interrupts?

Subject: Re: [stella] interrupts?
From: "Eric Ball/Markham/IBM" <eball@xxxxxxxxxx>
Date: Tue, 23 Apr 2002 15:26:49 -0400
Also consider that an interrupt automatically pushes the PC & PSR on the
stack and you only have 128 bytes of RAM.





                                                                                                                                        
                      "Eckhard                                                                                                          
                      Stolberg"                To:       <stella@xxxxxxxxxxx>                                                           
                      <Eckhard_Stolberg        cc:                                                                                      
                      @web.de>                 Subject:  Re: [stella] interrupts?                                                       
                      Sent by:                                                                                                          
                      owner-stella@bigl                                                                                                 
                      ist.com                                                                                                           
                                                                                                                                        
                                                                                                                                        
                      04/23/2002 02:45                                                                                                  
                      PM                                                                                                                
                      Please respond to                                                                                                 
                      stella                                                                                                            
                                                                                                                                        
                                                                                                                                        



> When (if ever) do we get an interrupt?  Is it possible to have the
> timer reaching zero to cause an interrupt?  Or must it be polled?

The 6507 processor has the interrupt pin removed to save costs.
Therefore it isn't possible to trigger an interrupt on the VCS.
The timer could generate an interrupt, but the processer won't
be able to sense it. You'll have to poll the timer, I'm afraid.


Ciao, Eckhard Stolberg


----------------------------------------------------------------------------------------------

Archives (includes files) at http://www.biglist.com/lists/stella/archives/
Unsub & more at http://www.biglist.com/lists/stella/





----------------------------------------------------------------------------------------------
Archives (includes files) at http://www.biglist.com/lists/stella/archives/
Unsub & more at http://www.biglist.com/lists/stella/


Current Thread