Subject: Re: [stella] Math riddle : Loading TIM64T with 43 burns only 36scanlines (not 37) From: "Eric Ball" <ericball@xxxxxxxxxxxx> Date: Mon, 10 May 2004 19:35:23 -0400 |
> Either store 44 instead of 43 to TIM64T (which is how the sample code > from Nick Bensema's original "How To Draw A Playfield" does it, although > the comments are misleading), or use BPL instead of BNE (which will > make it wait an extra 64 cycles until the 0 in INTTIM decrements to $FF.) Be very careful with this. IIRC once the timer expires the RIOT starts counting the number of cycles since the timer expired. So INTIM will be 0 for 64 CPU cycles, then start counting up from zero, incrementing every CPU cycle. Note: For definitive info on the RIOT check the datasheets at http://www.6502.org/datasheets/6532.zip ---------------------------------------------------------------------------------------------- Archives (includes files) at http://www.biglist.com/lists/stella/archives/ Unsub & more at http://www.biglist.com/lists/stella/
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