Lies, Damned Lies and Benchmarks.

[bmwtcu]

Nice! Where do I read about Mode 1975?

[at67]

Nice! Where do I read about Mode 1975?

Search for 1975 in https://github.com/kervinck/gigatron-ro ... ctions.txt

And:

Line 3149: https://github.com/kervinck/gigatron-ro ... dev.asm.py

Code: Select all

xora((1975>>8)^(1975&255))      #26 Poor man\'s 1975 detection
bne(pc()+3)                     #27
bra(pc()+3)                     #28
assert videoZ == 0x0100
st([vReturn])                   #29 DISABLE video/audio/serial/etc

The code detects 1975 as the parameter to sys_SetMode and sets [vReturn] to 0; this effectively switches the bit-banger to no video, no audio, no input, etc: which allows for 521 scanlines x 200 cycles worth of uninterrupted vCPU interpretation per video frame. (which is about double the number of available vCPU cycles compared to mode3, the single scanline mode).

P.S. There are no sync signals in this mode, so your monitor loses sync until you pass -1 back to sys_SetMode.

[veekoo]

Like in the OpenGL programming. You first calculate graphics in a frame and only after that you draw the frame.

[veekoo]

This 1975 mode could make Mandelbrot faster. New Mandelbrot draws in 1min 17sek in fast screen mode.