Mega SwinSID prototype - first test

Mega SwinSID is my new C64 SID replacement built on STM32 ARM Cortex M3 microcontroller. It runs at 80MHz and it uses integrated 12bit DACs for stereo output. To test this I implemented simple stereo reverb.
Currently it is in early stage and only basic SID emulation is working.

Category:

Science & Technology

Tags:

• commodore
• c64
• sid
• 6581
• 8580
• swinsid
• arm
• stm32
• synth

[jpb267]

Hey Swinkels!  Love this project!! What software are you using in this video and does it support ARM simulation?

[SwinkelsPL]

@jpb267 I'm using Ride7 free edition. It has builtin simulator and debugger but I don't use it. There is also H-JTAG on my screen for firmware flashing.

[HojoNorem]

Nice! Any chance of a I2S output to feed into a s/pdif transmitter IC? The output would need bumping to 16bit, unless you are already working in 16bit and the ARM's DAC if just truncating the unneeded 4 bits. Will you eventually be doing a stereo split mode as well?

[SwinkelsPL]

@HojoNorem Currently i'm focused on implementing more new features and i'm really happy with the quality of internal DACs. We don't need 16bit resolution since most of SID tunes uses 1bit square wave. Stereo split and voice panning will be implemented later.

[HojoNorem]

@SwinkelsPL Nice. Are you planning on having this software controlled? I can just imagine new SIDs that are written to play correctly on a classic SID chip, but utilise SwinSID features when one is detected. As for the 16bit output, even if you take the 12bit samples and shift them up to 16bit (still essentially 12bit) then that could be fed into a compatible reviver like a surround amp. What samplerate are you working at, 32Khz, 44? Keep it up ^_^

[SwinkelsPL]

@HojoNorem New features will be accessible on unused SID registers to maintain compability with existing software. 12bit is a DAC limitation, Internally sound is mixed with 16bit resolution. I used 31250Hz sampling rate on this video but I'm pretty sure that after software optimisation it can run at 96KHz with 128MHz clock speed.

[jaktrip]

Does not sound that basic at all. Cool stuff!

[1hdsquad]

@MattTheSpratt One man and his Droid - love that tune :)

[MattTheSpratt]

The second piece of music sounds like something by Rob Hubbard. What is it called?

[HojoNorem]

@SwinkelsPL Again very nice. If you can get the samplerate to the standard 32Khz (I think its 32) then that along with a I2S output like the original SwinSID that had the external DAC (just some solderpads for the signals is enought for me) then people can add the external DAC if they want or in my case a s/pdif transmitter for a digital connection to a AV receiver.

[chikin69]

This is a very nice hack. Is it a drop-in, pin-for-pin compatible replacement for the SID?