English Amiga Board - View Single Post - More than 4 sound channels

Thcm · 02 October 2013, 11:01

I wrote a Protracker replayer for the good old C64: http://csdb.dk/release/?id=112365
The mixing of 4 channels at 7800hz including different periods and volume needs about 50% of the cpu power of an unxepanded C64 running at ~1 Mhz. The other half of the cpu time is needed to output the 8 bit samples using NMI.

In theory it should be possible to have at least 8 full featured channels running on a stock Amiga 500 without any problems. Using double bufferd mixing buffers and clever use of tables should do the trick. There's no need for any expensive instructions. Even the Protracker replay logic uses a few rasterlines on the c64 using my approach.

02 October 2013, 11:01	#14
Thcm Registered User Join Date: Dec 2011 Location: Gummersbach Posts: 18	I wrote a Protracker replayer for the good old C64: http://csdb.dk/release/?id=112365 The mixing of 4 channels at 7800hz including different periods and volume needs about 50% of the cpu power of an unxepanded C64 running at ~1 Mhz. The other half of the cpu time is needed to output the 8 bit samples using NMI. In theory it should be possible to have at least 8 full featured channels running on a stock Amiga 500 without any problems. Using double bufferd mixing buffers and clever use of tables should do the trick. There's no need for any expensive instructions. Even the Protracker replay logic uses a few rasterlines on the c64 using my approach.