diffrences in Bitstream px100MHz to bitstream from October 2016

[adtbm]

Hello,

since i am running the bitstream px100MHz, the Rasterdemo from Detlef is not working correctly anymore and when pressing Restore-key, the demo "freaks out" completely (ultrahighspeed)
Also the SID sounds alot deeper and the sound speed is slower i would say the SID sound on the old stream was better, but i am no musician.
When using the bitstream from oct 2016, the demo runs normal (As it was shown in Neuss)
(of course i have set the MEGA65 to 50MHz after start)

[Paul Gardner-Stephen]

Hello,

There are a lot of changes that have happened.  One big one is the change in video mode, that has had cascading effects on a lot of fronts. First, it means that 50Hz is possible for most people on most monitors, now that we are using 800x600 instead of 1080p or 1200p. Unfortunately the FPGA is just not quite up to those higher modes, without slowing development down a lot.  Part of those changes is a difference in the hardware scalers.  Also, the default CPU speed changed from 48MHz to 1MHz in C64 mode. 

There are known problems with the sound output at the moment. You can use the config utility to switch DAC algorithms, but we know the SIDs are also currently too quiet, which means that they are closer to the noise floor of the DACs, which is also not good.  This and related sound improvements are on our list of things that need to happen, but please feel free to create github issues for them, if you wish, to help us keep track of everything that still needs to be done.

The speed of the sound is probably related to 50Hz/60Hz video modes for PAL/NTSC. Use the configuration utility to switch between PAL and NTSC, and you should hear the difference. I believe the demo was based on 60Hz NTSC output.

If we can find the source, we might well create an updated version of that demo, designed for the updated machine specifications.

Paul.

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