MEGA SwinSID project

  • Some time ago I designed improved version of SwinSID with PAULA like capabilities - 4 channel wavetable playback and 512KB SRAM memory for sample data. The goal of the new device is easy playback of Amiga MODs with small CPU usage and combine it with standard SID emulation.
    There is schematic and even first test firmware. Unfortunately i haven't got time to built and test this monster. Crisp also gave up with lots of prototype wires.
    Is threre anyone interested in such device?
    Any design suggestions are welcome.

  • Hi There!


    I read about SwinSID quite a while ago...
    finally i redesigned the x2-pcb on one layer and am putting it together just now...


    however if you need someone for prototype and/or final design works,
    i would offer my skills, as the SID is too good to let pass...^^


    best regards from switzerland,
    luke

  • Thanks for your effort. Nice to have alternative in single layer PCB. it is more DIY friendly because of DIP packages but the PCB is much bigger and i doubt it will fit into C64 case. There is also no SID socket connector onboard and soldering lots of wires with connector would be a pain (fast bus signals may cause interferences etc.) Finally there is some unused space on PCB - between AVRs and around audio out and SID signal socket.
    Do you think output opamp is really needed? Form my experience it doesn't improve sound in most cases - only when input impedance is very low.


    I'm working on the new project with Crisp now - Micro SwinSID with new 28pin ATMEGA88PA chip and 16bit PWM output. The new smaller chip would be ideal for single sided PCB like your. Maybe you want to try it out? The new firmware and schematic diagram is ready for testing. Crisp is building prototype now and soon this new device will be announced officially on my website.

  • hi there
    thanks 4 feedback!
    here's a little explanation for the design:
    the pcb measurements (100mm x 60mm) are my proto defaults, as i etch quite high complexity designs in my lab, i tend to skip unneccessary steps (like cutting FR4 because of the mess and tool usage). so normally that's the size of my first versions. as for fitting in a c64: true, it probably wont fit. i built the one for my synthesizer project... (same reason why there is no sid socket)


    anyway, i thought if it has to be smaller, it's gonna be smd (nothing serious, but smaller).


    i placed the op-amp because of filtering possibilities, and because it's recommended in the tda datasheet (not a big deal to get rid of it...).


    well


    i certainly will work through any schematics you submit for the new version, i thought of a beginners and a smd version.


    at this point i'd like to ask if you'd be interested in having a try using a cypress psoc5 with cortex-m3 core: its by far more powerful than an avr and has analog blocks inside already. i guess that could be interesting... (i will have a look at it)


    however, keep uf the great work!


    if i can help in any way, just tell me!
    best regards

  • Can you tell more about your synth project? It is based on AVR or other microcontroller?
    The AVR low speed is is the biggest limiting factor in creating complex, high quality audio synth. I considered switch to STM32 (Cortex M3) but i havn't got tools and skills to create and solder this ultra small chip. PSoC5 looks very impressive but I haven't heard about this chip before. The STM32 is much more popular and widely available. It has comparable performance and also integrated stereo DAC and ADC.

  • details for synth will follow,


    i have quite a bit of experience with stm32 and psoc(1), that's why i thought of the psoc5 (as the core is a cortex-m3, too). what i recommend to start with in terms of any psoc is any cypress eval kit. for the stm32 a nice and cheap gadget is the primer2 which has an integrated debugger and will get you going within 10minutes (raisonance, see http://www.stm32circle.com, really cheap source is mouser.com). for development on stm32 i meanwhile use keil uvision4 and a clone of the j-link called n-link (couple of bucks on e*ay).


    if you'd like i can set you up with a custom board with any of these.


    more details will follow,
    best regards, luke

  • STM32 is much more popular and i think it is better choice. For developing synth for C64 i would like to create custom board with STM32 and 512KB SRAM connected directly to this chip for storing sample data and also SID connector like in current SwinSID.
    Can you design schematic for this new SwinSID 32 project ?
    Is there any progress with your SwinSID based synth?

  • Quote

    I'm working on the new project with Crisp now - Micro SwinSID with new 28pin ATMEGA88PA chip and 16bit PWM output. The new smaller chip would be ideal for single sided PCB like your. Maybe you want to try it out? The new firmware and schematic diagram is ready for testing. Crisp is building prototype now and soon this new device will be announced officially on my website.


    Very interesting. Can't wait to build one to try it out.. ;-)
    This one doesn't need the external DAC anymore - right?


    Peter

  • STM32 is much more popular and i think it is better choice. For developing synth for C64 i would like to create custom board with STM32 and 512KB SRAM connected directly to this chip for storing sample data and also SID connector like in current SwinSID.
    Can you design schematic for this new SwinSID 32 project ?
    Is there any progress with your SwinSID based synth?

    hi there.
    I had problems with the login, and til today the recover password didn't work...


    ok, i'll create the schematics, do you also want a layout or pcb? i can offer 16MBit SRAM (got a couple of them here...), but i can also use something different.


    what i would recommend here:
    CPU: STM32F103ZCT6
    RAM: CY62167DV30 16MBit (1M x 16) SRAM connected to the FSMC (memory controller) of CPU
    Connectors:
    - DIL for plugging the board into original SID-Socket
    - USB mini (might be handy at some point, needs very little space and no extra components
    - SD-Micro socket (needs no extra components)
    - 20 Pin JTAG-Connector


    Best regards, Luke

  • Thanks for your help. I don't think we need SD card socket. I would rather add MIDI port to use it as stand-alone synthesizer. Most of C64 geeks already has SD card reader like SD2IEC. Stereo audio input (for ADC) would be nice addition too.
    Why to use 144 pin CPU ? I think it would be better to use 64 or 100 pin STM32 like STM32F105RCT6 from new connectivity line. It doesn't have memory controller, but i can access SRAM memory directly from software. What do you think about it?
    The new board should be designed with easy to buy parts. Unfortunately your RAM chip is not available at Reichelt.de

  • ok i'll spend some time on it this evening.
    do you know http://www.mouser.com ?


    so this would be the new specs:


    CPU: STM32F103 (64 pin if possible)
    RAM: something better available, connected to FSMC if available (you could still do bit-banging) or to ports
    DAC: STM32-internal stereo + external I2S (probably a MAXIM)
    ADC: STM32-internal stereo
    Memory: I2C or SPI Flash or EEPROM (couple of KBs) (SO-8)


    Clock input: to STM32-internal timer
    Clock output to SID: from STM32-internal timer (lets you drive the onboard SID from STM32 without other hardware, or run the SID on 2MHz etc.)


    Analog subsystem: audio switches (MAXIM) to let you route any in and out signals between inputs, outputs, DACs and SID
    (daisychain sounds from STM32 through SID to output or whatever you can imagine)


    Connectors:
    - DIL for plugging the board into original SID-Socket
    - USB mini (load patches and waveforms to STM32 in mass storage device mode as an example)
    - MIDI in
    - MIDI out (?) (maybe just as a pin header)
    - 3.5mm stereo input to adc
    - 3.5mm stereo output
    - 3.5mm mono output from SID
    - 3.5mm mono input to SID
    - 20 Pin JTAG-Connector


    I think that's it for the moment,
    more details this evening

  • I already ordered an STM32F105RCT6 (256KB FLASH, 64KB RAM) chip for prototype. It will be build on breadboard with LQFP->DIP adapter for STM32 and will contain only JTAG, SID connector for C64 and audio out. After first tests I will create PCB for full version with additional chips and connectors.

  • Hi there


    i was a bit slow this weekend,
    but I had a look at the schematics, and I think somehow it gets a bit tight with pins.
    So if you still want the complete schematic please tell me exactly what chips you are already using,
    what you're planning to use, and I'll do whatever is possible!


    best regards