Re: Re: [stella] Horizontal

Subject: Re: Re: [stella] Horizontal
From: Dennis Debro <ddebro@xxxxxxxxxxxxx>
Date: Wed, 5 Mar 2003 5:25:24 -0500
Hi Andrew,

> Since you're doing a HMOVE on the same line, cycle 24 *is*
> technically inside the extended HBlank, so I'd say this is
> the root of your problem.

I thought HBLANK was the period the electronic beam moves from the right side of the screen back to the left. If that were the case then HBLANK time is static to 68 pixels or ~23 cycles, right?

I ran a quick test on what you said and you're right. Apparently the HMOVE extends the HBLANK period. I didn't know that. I thought it was just another call that took up 3 cycles of your HBLANK time (as well as moves players and the such). I changed the HMOVEs to bit $00 just to waste 3 cycles and the players don't "bounce" at position $0E.

Thanks for clearing this up for me.

Take care,

Archives (includes files) at
Unsub & more at

Current Thread