+cubanismo Posted October 19, 2021 Share Posted October 19, 2021 (edited) I've written up some GPU code to draw a string of characters with the blitter. It works, but it is crazy slow. It takes about half a second per character blitting 6x12px characters from a 1bpp surface to another 1bpp surface. There are a few other things going on: The 68k is in a tight loop reading a word from a main memory location to see if the GPU is done yet. The GPU is servicing the object processor interrupt once a frame to reset the object list and do some crappy animation experiment stuff. Two ~half-screen-sized 1bpp surfaces are being displayed by the OP So the system isn't idle, but it's not doing anything crazy either. Wondering if anyone has theories on what's going on? Here's a link to the GPU code in question: https://github.com/cubanismo/skunk_usb/blob/03de2e2fa4a/ffsgpu.s#L334 And you can find the rest of the related source files in that repo as well, e.g.: https://github.com/cubanismo/skunk_usb/blob/master/usbffs.c https://github.com/cubanismo/skunk_usb/blob/master/ffsobj.s https://github.com/cubanismo/skunk_usb/blob/master/startffs.s Edited October 19, 2021 by cubanismo Edit: Fixed the link to the actual function to use an absolute git revision rather than pointing to latest version. Quote Link to comment Share on other sites More sharing options...
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