SID interconnection test

Testing/Troubleshooting
1

Hi,

I can’t get my SID to make sound. I’m using a PIC18F4685 with latest boatloader and MIOS, which all were loaded correctly as far as I can see. Uploading apps via MIOS studio is also going good.

SID testtone app does not produce any sound. I loden SIS interconnection test and have troubles doing the test. I am using the modulationwheel in MISO studio, man what a B*atch is that. I need finetune capability to send ModWheel 0 through 14 over MIDI but the thing is so inaccurate that the first value after 0 is 5. So, couple of questions:

  1. Is it necessary to remove the SID for this test? (I did all the testing with a SID plugged in)

  2. How can I send finetuned ModWheel messages over MIDI without a physical modwheel?

The reading I can get right now are the following:

ModWheel 0: SID pin A0 5V

ModWheel 5: SID pin RES# 5V

ModWheel 6: SID pin D0 5V

ModWheel 9: SID pin D3 5V

ModWheel 11: SID pin D5 5V

ModWheel 14: SID pin CS# 0V

Other ModWheel values are impossible to generate with MIOS Studio, at least for me, but CS# getting no current does not look good to me. What should I check first?

Thanks,  Alex.

2

Hi Alex,

it is not required to remove the SID for this test.

MIDI-Ox provides a control panel, from where you can easily send a specific ModWheel value.

Reg. ModWheel value #14: I just have noticed, that there seems to be an error in the released test application - within the SID_SetPin14 function in main.asm, SID_SR_LAT_WR is set and not cleared (therefore CS# is propably always 0).

I’m sure that I fixed this months ago, but it seems that I forgot to upload the new version

Best Regards, Thorsten.

3

No, I was wrong - the version is up-to-date

WR# should be 0 when ModWheel #14 is sent, it should be 5V on any other ModWheel value (see main.asm header)

Best Regards, Thorsten.

4

I completely read over the ModWheel 14 -> 0V part in the main.asm, how stupid of me :-[

I will test the other values tonight and post the results here.

5

OK, tests went fine. Loaded SID V2 HEX file, went fine. Still no sound  :cry:

I connected headphones to the audio-out of the SID, is that possible or is an amplifier necessary?

6

Yes, the output current is not high enough for a headphone, an amplifier is required.

Did you already check the clock connection between core and SID module? The SID won’t run without.

Do you have a V2 or V3 core module, a V2 or V3 SID module? There are small differences, which are documented at my website!

Best Regards, Thorsten.

7

Hi TK,

both the Core and SID are V2, but I used the old docs to interconnect them. I will try to measure the clock signal, I already insulated the connection… Should I measure any particular voltage on those pins? Tomorrow I will also connect the sid to my amp.

8

The clock signal cannot be measured with a common measuring instrument (you would need a scope…), but if you want to ensure 100% that the connection is available, just unplug the PIC/SID and use your multimeter in ohmmeter mode (0 ohm between the PIC->SID pin means: connected…)

Best Regards, Thorsten.

9

I soldered a new plug to the audio out of the SIDboard and uploaded V2 again: it makes noise! And I don’t mean digital or static noise but real SID music noise  ;D

One thing though: the SID testtone app did not produce any sound, just digital noise, might that app be incompatible with the 18F4685 PIC?

10

Great! :slight_smile:

The testtone application should work w/o compatibility problems. The second MBHP_SID module is not serviced of course, but I just changed this in the new version: http://www.ucapps.de/mios/sid_testtone_v2.zip

Best Regards, Thorsten.