problem making a midibix step C

[chocolat2000]

Hello,

I began building a midibox step C

First, i mounted 2 cores and 2 sid modules. I liked them together, and whow, great sound !

But now, i mounted 2 other cores and 2 other sid modules, and when i link everything, i have no sound from sid 2,3 and 4 (i had sound from the sid 2 before, and i send the "link" control to the master)

Very strange, when i un-link (undersand : un-solder the power of the sid 3 and 4) the sound come back to the 2th sid !

Other thing strange : when everything is soldered together, i can't say i have no sound from sid 2,3 and 4. Actually, i hear the "phantom" sound from the sid. I also hear the "chtritch" when i change preset and the phantom sound change. So the slaves sids receive some datas, but apparently not the "note on".

Someone understand this ?

PS: i use the optimised PSU, with a C64 power supplie

[TK.]

Hi,

sounds like the MIDI connections of the slaves are wrong - check the schematic: http://www.ucapps.de/mbhp/mbhp_4xsid_c64_psu_optimized.pdf - the MIDI Out of the master goes to the MIDI IN of all slaves. If you would connect a MIDI Out of a slave to this line, the described effect would happen - no MIDI transfers would be possible anymore.

Best Regards, Thorsten.

[chocolat2000]

I double checked the connections, it seems to be ok.

I'm suspecting the alim. Because, if i solder all the sid's and core's, and if i solder the midi link between core 1 and 2 but not core 2 to 3 and 4, the sid2 loose sound. If i unsolder the alim of core 3 and 4 (without touching the midi link connection), sid2 come back to life !

I triple checked the sonnections, but everithing seems to be correctly soldered.

I'm a bit despaired  :(

[TK.]

Hm... did you ever check the slave cores standalone? Maybe there is a short circuit on those core modules.

You could try to find out the "bad" core by testing them standalone, like you would test a master core. You don't need to update the firmware, just remove the MIDI-Link connections and attach MIDI In/Out directly on the slave core which should be tested. Now you can try to access the core with MIOS Studio (e.g. open the Debug Window, select "SRAM Read", enter address 0x000 and No.Bytes 0x10, the core should return 16 bytes)

Maybe you should test this on the working master core before in order to get a feeling of the handling, then continue with the slaves. If a slave doesn't reply on the SRAM Read request, you know that this is the module which causes the problem.

Best Regards, Thorsten.

[chocolat2000]

I cannot understand, it is now working !

I un-soldered every sid and tried them alone -> perfectly working (after a re-burn of the pics)

Then i resoldered them together and it works !

The only thing is that the first time i send the mios and midibox_sid prog when everything was soldered.

Now i programmed them seperatly. Could this be the problem ?

[TK.]

Now i programmed them seperatly. Could this be the problem ?

uploading (and especially updating) MIOS through a master core is not trivial, because you need to reset the slave seperately. Since the MIDI Out of your slave is not connected to the PC, MIOS Studio cannot determine if a code block was uploaded correctly.

For an expert it's easy and comfortable to upload code in this way so long he knows what he is doing, but for a newbie it's just too error prone, and it's especially hard to think about what went wrong here (too many possibilities). Therefore I will change the suggested upload procedure for the slave modules at my website - thanks for testing!

Best Regards, Thorsten.