Andrew Collier wrote: > If I used IM1 this would require that either, a) the screen goes in sections A > and B, and the interrupt routine is actuially visible in pixels - or b) the > moveable window goes in sections A and B, and I have to duplicate the > interrupt routine in nearly every page of memory.
That's the approach I was taking years ago for Chrome, I'd have a couple K dedicated to the main core of the code and interrupt routines at the start of many 32K chunks of code and sprite data, so AB pages could be shifted around keeping the screen in CD - with the 8K above the screen holding other data. Thomas Harte wrote: > If you interrupt routine is small, could you not also just switch off > the first one or two scanlines of your display, and even grab a few > extra cycles out as a result? Or can you not enable and disable the > display per scanline? That could be done using line interrupts, perhaps use the Frame Interrupt to switch the screen off, then just a single line interrupt to trigger an interrupt at a certain scan line and re-enable the screen. Colin ===== Quazar : Hardware, Software, Spares and Repairs for the SAM Coupe 1995-2008 - Celebrating 14 Years of developing for the SAM Coupe Website: http://www.samcoupe.com/
