[midnightclubbed]

Thanks for filling in the details on the disassembly, I'm surprised the matrix functions weren't in asm but I believe you. If I remember correctly NOA did the CPU/lib side and NCL did the RSP code (definitely in asm) and hardware side.

The back to back multiplies definitely could cause hangs on real hardware (actually I'll back up and say it certainly could hang a dev-board and I think the hardware was the same as production). I don't know if there were particular registers or data that caused the hang but I remember QA picked up hangs with builds that had them in there.

Adding extra frame buffers lets you output at 60Hz without tearing but you'll bounce between duplicated frames and single frames. You technically get 40fps (or whatever) but smooth camera movements feel 'off'. That extra frame eats pretty badly into the remaining space in the 2Mb base memory (at 640x480 you could have just one frame buffer and render interlaced, so long as your frame rate always hit 60Hz).