Level of SID Implementation?

Es gibt 7 Antworten in diesem Thema, welches 4.493 mal aufgerufen wurde. Der letzte Beitrag (6. Oktober 2021 um 09:58) ist von 0xdeadbeef.

  • Hi,

    I am a little bit concerned, if it would be perhaps necessary to buy additional SIDs 6581+8580 (two pairs I assume for the full expierience). They are already been sold at very high prices and the whole C64 resellingmarket seems to be at significantly raised prices since less than 2 years ago.

    Because of my expieriences with the good but not perfect SID implementation of the TCv2 from IComp I would like to know if it is possible to define every of the 4 SIDs as a specific model. And what are the expierences and reachable goals if it comes to the percentage of accuracy compared to the original SIDs. How well is it working compared to "FPGA-SID" and "TCv2"?

    Thank you.

  • nonic 5. Oktober 2021 um 21:15

    Hat den Titel des Themas von „Level of SID Implementation“ zu „Level of SID Implementation?“ geändert.
  • How well is it working compared to "FPGA-SID" and "TCv2"?

    Let me quote from a review from RGCD from February 2021:

    Honestly, the MEGA65's SID emulation is one of the best I have heard on a hardware C64 clone to date - far superior to TheC64 and cleaner sounding than the otherwise brilliant Ultimate64. So whatever the MEGA team are doing on that front, they're doing it right!

    :DJ

  • Just for the record: the UltiSID implementation in the Ultimate 64 is not bad for normal games, but far from perfect. What seems to be a worst case scenarios is playing samples in BreadAmp. When using the samples for a 6581 and configuring the UltiSID in 6581 mode, the resulting sound quality is somewhat terrible and not even close to that of a real 6581. An ArmSID does a much better job here. Admittedly, this is a very specific scenario but it shows that some details of the 6581 are emulated much worse by the UltiSid than e.g. by an ArmSid. So using the current state of the UltiSID as a general benchmark for SID emulation seems like a bad idea.

  • Playing samples on the 6581 was done by exploiting a bug in the hardware which caused a distinct popping sound when playing with the volume bit of the noise channel. So anything that fixes that bug including Commodore's own 8580 will produce a more muted output on those test cases. It's also not a you hear it you don't situation. It's just a bit more muted. I grew up mostly with a C128 although we had a C64 before that and I can remember a Text-to-Speech cart working properly with it

  • While implementing the SIDs for the MEGA65 we took into account, that Commodore had two (main) revisions of the SID chip. The 6581 and the 8550.
    If you take the 6581 by itself everybody will agree, that even within the chip version the revisions vary and almost not one 6581, even within those revisions ,sounds like the next one.

    We know, that our SID implementation is quite awesome :wink: At the moment more and more musicians are joining our discord, helping to even more finetune

    our current SIDs. On top of that, work is ongoing, that we will give the possibility to choose between 6581 and 8550 for each of the 4 SIDs.

    Also on the list, but further down is the MSSIAH implementation, to get the cartridge working on the MEGA65

    Together with the 4 DACs we believe the MEGA65 will gain more attraction towards retro musicians as well.

    PS: While writing this, i am listening to .MOD files from the Amiga, via shuffle mode, on the Manche Modplayer for the MEGA65 :wink:
    Bitte melde dich an, um diesen Anhang zu sehen.

    Bitte melde dich an, um diesen Link zu sehen. <- here you can find all MEGA65 related files, games, etc.

    Bitte melde dich an, um diesen Link zu sehen. <- MEGA65 main Homepage. links to all important MEGA65 sites (links on top of the page to Files, Forum, GitHub, Manual,etc.)

    Bitte melde dich an, um diesen Link zu sehen. <-Pauls Blog - constant updates about current tasks, project status, etc.

    Bitte melde dich an, um diesen Link zu sehen.,Bitte melde dich an, um diesen Link zu sehen. <- All Open-Source information regarding MEGA65. Found Bugs ? create an issue there please!

    Bitte melde dich an, um diesen Link zu sehen. <- Join for live chat support and more --- The Future is 8-bit !!!

  • While implementing the SIDs for the MEGA65 we took into account, that Commodore had two (main) revisions of the SID chip. The 6581 and the 8550.
    If you take the 6581 by itself everybody will agree, that even within the chip version the revisions vary and almost not one 6581, even within those revisions ,sounds like the next one.

    We know, that our SID implementation is quite awesome :wink: At the moment more and more musicians are joining our discord, helping to even more finetune

    our current SIDs. On top of that, work is ongoing, that we will give the possibility to choose between 6581 and 8550 for each of the 4 SIDs.

    Also on the list, but further down is the MSSIAH implementation, to get the cartridge working on the MEGA65

    This is great news as I enjoy using my MSSIAH cart and looking forward to making music with 4 SIDS in my MEGA65 one day:D

  • Playing samples on the 6581 was done by exploiting a bug in the hardware which caused a distinct popping sound when playing with the volume bit of the noise channel. So anything that fixes that bug including Commodore's own 8580 will produce a more muted output on those test cases.

    I am very well aware of this. When I first got a short board with an 8580, the first thing I tried was checking the sample in the intro of "Ghostbusters" and expected it to be inaudible. Well, it wasn't. Actually, I couldn't really tell a difference from a 6581. As far as I recall, this also sounds OK on an UltiSID in both settings. Probably a somewhat different approach to play the samples compared to other games and BreadAmp.

    Anyway, try BreadAmp with an UltiSID, both in the 6581 setting and judge for yourself. IMHO this is not just a volume thing. It sounds terrible and nothing like a real 6581 at all. Surprisingly, it sounds much better using the samples meant for the 8550 which makes you wonder if there is really just a 8580 emulation anyway with slightly different filter settings for the 6581 "emulation".