[stella] why -68?

Subject: [stella] why -68?
From: ben <ben@xxxxxxxx>
Date: Wed, 07 Nov 2001 01:40:41 +1100
z26 is awesome btw  :)  Thanks John

Anyways, I have a question regarding its cycle output.  Why does the TIA
clock start at -68 and occupy 236 clocks (-68 to 157)?  isnt it supposed to
be 228?

(  0   2   0 -68) ( 97  97  96  96  96) nvbdIzc 00 60 00 fd  f5c2: d0 fb
bne  f5bf    
....
(  0   2  75 157) ( 97  97  96  96  96) nvbdIzc 00 68 00 fd  f5bf: e8
inx          
....
etc
....

Does this mean that the TIA clock is different to the 6502?  I am using
3584160/3 Hz (228*262*60/3) for the CPU, which gives 76 cycles per
scanline.  What should the TIA clock be?  (236*262*60) 3709920Hz?

cheers

Ben


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


Current Thread