quesitons and answers: Atmega8Sid Emulator

[chris]

If you have some questions relating the sound generation by the Atmega8Sid Emulator, place it here.

Here you will find the source code for the project.

[kuk]

[i'll do it in english]
hi chris,

i tried to conatct you via the atmega SID thread over at www.mikrocontroller.net...But this here is even better.
My question there was, whether you think it would be possible to stuff your SID-Emu-Code into an arduino Library. I have the Emulator working as n Arduino "shield" for a month now and it's great. Still, it feels a little odd that it always needs a controller board (as long as i don't touch your original code, which unfortunately does not compile using the Arduino IDE. i tried a few things, but always got stuck at some point).

i was working on such a synth Library, but your SID approch seems much superiour to my timers chaos. Full SID-Emulator hin_oder_her the 3 channels with individual ADSR and different waveforms is really something people would dig on their arduinos. Is there a technical reason this can't be done? I clearly understand that the code runs best on a dedicated atmega, but hard-coding some voices and reading a pushbutton should be possible. Personally i wanted to midi-fy this thing to be able to use it with this here.

Seeing you're are probably busy working on the chTinySizer now (which BTW looks verrry interesting), i would give it a more serious try if you're saying it could be done. Is there some general info on the timer usage and PWM calculations for the waveforms? I'd be satisfied with only 2 channels if that made a difference.

It's really a great work. Thank you.

All the best from berlin,
kuk

[chris]

Helo kuk,

Still, it feels a little odd that it always needs a controller board (as long as i don't touch your original code, which unfortunately does not compile using the Arduino IDE. i tried a few things, but always got stuck at some point).

You are right, it's al little bit odd needing separate electronics for the SID-Emulator. The code of the SID-Emulator is very time critical and memory cirtical. My experience with people using the arduino board is: they are often beginners or not so experienced in programming. So it would be almost impossible for this people to manage implementing some of their own code in the SID-emulator without violating the time or memory limits. Therefore I decided to give the SID-emulator a separate processor.

i was working on such a synth Library, but your SID approch seems much superiour to my timers chaos. Full SID-Emulator hin_oder_her the 3 channels with individual ADSR and different waveforms is really something people would dig on their arduinos. Is there a technical reason this can't be done? I clearly understand that the code runs best on a dedicated atmega, but hard-coding some voices and reading a pushbutton should be possible. Personally i wanted to midi-fy this thing to be able to use it with this here.

One reason why the SID-Emultor is so memory and speed consuming is the aim to be compatible to the C64's SID. Its possible to create a 3 or more channel synth by giving up this compatibilty. It should be also possible to implement this directly on an arduino. The reason why I wanted to be compatible is the big resource of SID-Sounds. If you extract the register commands of the SID-Files and put them directly to the emulator you can make this sounds audible.

chris

[kuk]

Hej chris,
thanks for answering. i totally understand your reasons for making this a seperate board. And compatibility to the SID makes the project even more impressive. I'll see.. i had a good reading on AVR Timers and analog stuff yesterday. Maybe i can get to understand the principles better and create something like a Lite version as an Arduino Lib. It's just that this is the first Atmega8/168 based synthesizer i've met with not only great sound but totally universal interface (the registers). I didn't recognize the real advantage of your SID compatibilty at first (Sid Dumps). No nostalgia here, i just recently bought my first C64 on a flea market to rip the SID out (thank you i don't have to). Not because i loved the sound so much, but just because i thought it would be "the cheapest" solution to build an electronic synth around an Arduino.

BTW i do encounter some strange "sudden restart" problems with the SID shield from time to time. I'm not yet sure if this is just a power problem (i added some caps). Could it be that i'm sending data too often or something like that? Why did you chose 9600 as the baud rate? is this necessary?

kuk

[kuk]

Another thought

even if the code is better run on a seperate system, a main advantage of an Arduino version would be that many more people could actually just try this thing out. (you do need a programming tool, or am i missing something?) I got the opinion that the "un"compatibilty just comes from the Arduino software adding its own headers instead of recognizing yours. Maybe one can hack te arduino IDE to upload just the HEX, but i didn't try that.

[chris]

BTW i do encounter some strange "sudden restart" problems with the SID shield from time to time. I'm not yet sure if this is just a power problem (i added some caps). Could it be that i'm sending data too often or something like that? Why did you chose 9600 as the baud rate? is this necessary?

In the present implementation of the AtmegaSID increasing the transmission speed of the serial link will not give better results due to the internal program structure ( the program can not collect the comands faster ). I choose the speed of 9600 baud because its possible to connect the AtmegaSid directly to the PCs serial link and receive the comands directly from the PC without the Arduino processor.

p.s.: probably it's easier to write in German, you may open a new thread in German

[leblebitozu]

Hi,

How can I import stock SID files to Atmega8SID, Can I put SID songs together an atmel dataflash and play from it directly ?

Thank you for advice.

[chris]

How can I import stock SID files

That's a very difficult issue. You have to convert the sidfile in a registerlist and include this register list into the code.

chris

[Telekatz]

Hi,

how do you convert the sidfile to a registerlist?

Telekatz

[chris]

For some Sid Files it is possible with this program:

http://www.mikrocontroller.net/attachme ... ractor.zip

But only for about 40% of the sid files.