[toneburst]

Well, I've managed to desolder 5 of the 8 caps, just using the iron and solder-sucker, and a pair of needle-nosed pliers.

I've been cutting the caps in half, then using combinations of sucking solder from both sides of the board, adding more solder, and gently waggling the legs with a pair of needle-nosed pliers.

It's been taking me 10 minutes per cap though, though, so progress is frustratingly slowwww, but I have so far managed to avoid damaging the pads too much, I think (fingers crossed).

I've just invested in some liquid flux and an applicator for it, so they will hopefully help with those pads connected to the ground plane, when they eventually arrive (another eBay order).

3 more caps to go!

Cheers again for the encouragement and tips, guys!

a|x

[chimchim]

I've found a "de-soldering" copper braid to be helpful for stubborn little blobs that don't want to let go.

[toneburst]

Well, I've managed to complete the desoldering of the 8 misplaced capacitors now. I eventually found it easiest to add molten solder to the base of the legs from the top side, once I'd snipped the cap in half, then pull the legs out with the pliers. The only problem then is clearing the excess solder from the holes, which I eventually did by holding the board on its side, heating the hole from one side, and sucking the solder out the other.

I've done all the other SID section caps now, and basically have only the SID transistors, and the caps next to each SID chip socket (which I'll mount in machined-pin sockets I think) to do, and the baseboard is finished. Then the troubleshooting will begin, I suspect! There are still quite a lot of really horrible-looking solder joints on the back of the board, and I'd be very surprised if at least some of these don't cause problems. I have some liquid flux on the way though, so hopefully I should be able to resolder in a more satisfactory manner, where necessary.

Oh, and I still have to do the resistors for the CS LEDs, but I'll leave them until after I've wired up the LCD and tested the rest of the board.

Incidentally, what kind of potentiometers and caps should I get, to implement adjustable feedback, as Wilba  has?

a|x

[toneburst]

Mainboard nearly finished, at last!

http://158.223.20.36...board_080109_01

It looks pretty horrible on the back of the board though, so fingers crossed it actually works...

Gotta solder-up the LCD cable next. I seem to have mislaid a transistor, too somewhere along the way, so I may have to order a replacement, which is a drag.

a|x

[toneburst]

Well, I finally finished all the soldering on the mainboard, with the exception of the resistors for the Control Surface LEDs, which I will leave until I start work on the CS, and one of the transistors on the SID section, which I seem to have mislaid somehow. I used machined-pin sockets for the SID filter caps, just in case I fancy experimenting with different types later on.

Last night, I populated all the IC sockets except for the SIDs (still waiting for my order from Wilba), and the Core chips. I added the first core PIC, connected an old LCD I had left over from my last bout of MIDIBoxing, hooked up my trusts C64 PSU brick, held my breath, and.. turned it on.
Initially, I got nothing, and my heart sank. Then, it occurred to me that I probably needed to adjust the LCD contrast pot, so I dug out my a screwdriver, tweaked adjusted the pot slightly, and, with immeasurable relief, saw:



I then dropped in the 2nd Core chip, connected the LCD again, and:



I'm so glad everything seems to be working, so far!
Here's a photo of the whole board, as it stands at the moment. You may just be able to see the missing transistor on SID #4. I also noticed after taking the photo, that one of the capacitors for SID #1 is also missing. I've now soldered that in. I tried to keep everything as neat as possible, on the top of the board, at least, but it is very hard to keep all the components straight, I find. All the ID sockets are slightly crooked, the capacitors and transistors are at slightly different angles, which bugs me a little, I must admit. Not enough for me to want to resolder everything, though.



My next move will be to drop in one of the SIDs I have left over from my previous attempt, and see if I can get the SID application uploaded, and get some sound out of it! The SIDs are a pair of 8580s I salvaged from eBay-bought C64s, so they should have the same power and filter-cap requirements as the 6582 revision chips that will eventually be installed. When the chips from Wilba arrive, I will compare the sound from the two different types, and may leave a pair of 8580s in there, just to have the option (though I guess this might have a detrimental effect on Super-Poly mode operation- thoughts on that, anyone?).

Unfortunately, I have other stuff to do at the moment, and probably won't get to work on the MB-6582 again until Tuesday evening, but I'm looking forward to moving on to the next stage!

a|x

[toneburst]

Now I remember what had me scratching my head, and eventually pulling out my hair, for weeks last time around, when I was making my first Core + SID modules..... and I've hit the same issue again.

No MIDI. I'm not getting any MIDI output from the mainboard when I turn it on, though I still see 'READY' on the display.

Also, I haven't been able to upload the test-tone application using MIOS Studio, either by using 'Smart' or 'Manual' modes. I guess this means both MIDI In and Out are not working. I'm getting an output from the MIDI interface (an M-Audio MIDISport 2x2) when I try to output the test-tone application, but there are no flashing LEDs on the interface indicating anything coming out of the mainboard.

I've been through the tests on
http://www.ucapps.de...debug_midi.html
though I'm a bit confused about this one
http://www.ucapps.de...mbhp_core_5.jpg
Maybe I should be installing some more jumpers?

I've also swapped-out the optocoupler for one from the Core module I eventually got working before.

Anything else I should try?

a|x

[Wilba]

from http://www.midibox.o...i/wilba_mb_6582

Quote

What is the function of J11 (directly below U1_Core1)?

Using a jumper, this allows you to connect the PIC's serial output to the MIDI port. You would only need to use this once for the first upload of MIOS and the MB-SID V2 firmware, thereafter connect the master PIC (1) to the MIDI out and after uploading new MB-SID V2 firmware, the master PIC can clone itself to the other PICs across the CAN bus.

from http://www.midibox.o...struction_guide

Quote

J11 at the bottom of the board is used to switch which PIC's serial output is connected to the MIDI Out. You use this during uploading of MIOS and the MB-SID V2 firmware to each PIC. Place a jumper vertically across two pins to switch between the PICs 1,2,3,4 (1 is the master, on the right). Leave the jumper in position 1 when you've finished. All PICs receive the same MIDI In, which is OK during uploads and the MB-SID V2 firmware also requires them all connected to MIDI In. I've labeled this 1,2,3,4 and the Cores/PICs are identified 1,2,3,4 but the device IDs you burn into the PIC are 0,1,2,3.

For what it's worth, CSG 8580R5 are identical to the CSG 6582A I sell. It's possible MOS 8580R5 might sound slightly different to the CSG 6582A I sell, but highly unlikely. I say this because some SID fans think they can hear a difference between CSG 8580R5 and the older MOS 8580R5. I am skeptical though. Some people think they can hear a difference when using gold-plated phono jacks.  :P

[toneburst]

Quote

J11 at the bottom of the board is used to switch which PIC's serial output is connected to the MIDI Out. You use this during uploading of MIOS and the MB-SID V2 firmware to each PIC. Place a jumper vertically across two pins to switch between the PICs 1,2,3,4 (1 is the master, on the right). Leave the jumper in position 1 when you've finished. All PICs receive the same MIDI In, which is OK during uploads and the MB-SID V2 firmware also requires them all connected to MIDI In. I've labeled this 1,2,3,4 and the Cores/PICs are identified 1,2,3,4 but the device IDs you burn into the PIC are 0,1,2,3.

Ah, so it WAS a jumper... Thanks very much for that Wilba. Apologies for not reading the docs properly. I will try that as soon as I get a chance.

Quote

For what it's worth, CSG 8580R5 are identical to the CSG 6582A I sell. It's possible MOS 8580R5 might sound slightly different to the CSG 6582A I sell, but highly unlikely. I say this because some SID fans think they can hear a difference between CSG 8580R5 and the older MOS 8580R5. I am skeptical though. Some people think they can hear a difference when using gold-plated phono jacks.  :P

I think if you listen to something for long enough, you can convince yourself you're hearing all sorts of things!

Thanks again for the info!

Cheers,

a|x

[stryd_one]

Quote

Some people think they can hear a difference when using gold-plated phono jacks. 

That's total BS. Only my solid silver power cable with titanium shielding will do that. Buy yours now for the low low price of 900 Euro per inch.

[toneburst]

Quote

That's total BS. Only my solid silver power cable with titanium shielding will do that. Buy yours now for the low low price of 900 Euro per inch.

Ha!
If we were all audiophiles, we wouldn't be here ;)

a|x

[stryd_one]

LOL That gets my vote for new midibox slogan.

</hijack> sorry!

[toneburst]

Well, progress is being made!

I've installed all 4 Core chips, and managed to upload the SID Testtone application to all 4 (one at a time) via MIDI from MIOS Studio.

All the output buffers seem to work except for SID 7, for some reason, which is encouraging. I don't get any tone when I connect pin 14 of this SID socket to pin 27 of the SID chip socket 8 either, so I'm guessing the signal from Core 4 isn't getting to SID socket 7 at all, for some reason. I will have to check my soldering around that area.

Also, for some reason, the LCD outputs of Cores 2 and 4 don't seem to work (I just get a row of blocks on the top row of the LCD, but no change when I upload a MIOS application etc.). Again, I'll have to check my soldering, I guess. Slightly worryingly, I was getting a clear display from Core 2 yesterday. I guess it could just have been a bad solder joint, and moving the board around today broke the connection.



Also, I found the missing transistor, on a separate little bit of cardboard. Not sure if I cut it off the strip myself and forgot about it, or it was on it's own from the beginning...

Really good to get my first sounds, anyway, even if it was just a 1kHz tone...

a|x

[Max Romantschuk]

Replying so I can follow the thread more easily. ;)

Keep up the good work! :)

[Goblinz]

Quote

Also, I found the missing transistor, on a separate little bit of cardboard. Not sure if I cut it off the strip myself and forgot about it, or it was on it's own from the beginning...


a|x

It's on it's own... I misplaced mine for a while!

[toneburst]

Quote

It's on it's own... I misplaced mine for a while!

Ah... I didn't think I'd cut it off. Glad for the confirmation I'm not completely losing my memory (if not my marbles).

a|x

[toneburst]

OK, I've been doing some resoldering on the back of the board, and am happy to report that te LCD now works with all 4 cores! When I say 'resoldering' I basically just mean remelting the solder on the dodgy-looking joints, trying to get the solder to adhere to thos stubbornly cold pads. I actually bought some liquid flux the other day, but I'm embarrassed to say I don't know how to use it, so I've been struggling on by just turning the iron to a higher temperature than normal, and trying to hold it to the pad for a little longer.

That 7th SID socket is still not working, though, annoyingly. Anyone any ideas how I should troubleshoot this? I'm now getting a tone from the socket is I connect pin 14 to pic 27 of SID socket #8, so the 1kHZ tone is not getting to socket #7, but nothing is arriving at the audio output. I don't know enough about the signal-path to know where the problem is most likely to lie. There don't seem to be any obvious soldering issues in this are- but then again, there may be issues that a more experienced solderer would notice immediately.

Also, anyone any idea why my MB-6582 should interfere with my FM radio, from several metres away..?

a|x

[toneburst]

I got a bit impatient, and thought I'd try inserting my two old CSG 8580R5 SID chips in SID sockets #1 and #2, and try uploading the SID application from the 'setup_8580.hex' file, again via MIOS Studio.

The application upload went well, though it took longer than I thought it would. After MOIS rebooted, the application successfully formatted all 8 memory chips, which was a relief, as I had trouble soldering the sockets.

I plugged-in my headphones, and was greeted by a loud buzzing noise, and the occasional crackle. I tried triggering different notes from the keyboard in MIOS Studio, but just got slight variations on the same loud buzz. Then I remembered that I should have jumpered across the audio I/O headers, so I added the jumpers.
Unfortunately, that didn't seem to make any difference, and I'm now wondering if I might have trashed my SIDs. This suspicion is strengthened by the fact that both SIDs seemed to get noticeably warm (though not actually hot), almost as soon as I switched the power, on. I'm pretty sure I had them working in my modular SID v.1, so I think they were functional before I put them in my MB-6582.

Is it likely that I have damaged them in some way? I really hope not, though it's not the end of the World, as I have my 8 chip order from Wilba.

a|x

[toneburst]

Ooops!

Very silly mistake! I should obviously have been uploading the MB6582 version of the SID application. I've now done that, and woooo... it works! I've only tried SIDs in slots 1 and 2, but they definitely seem to work now, which is brilliant!! Loads of background noise, mind. Can't remember if I was getting this before, when I had the SIDs in the modular SID board from SmashTV, but I'm definitely getting notes, and it sounds cool!

Have uploaded MB6582 to Cores 1 > 3, and left the Test-tone application on Core 4, until I can work out what the problem is with the audio out from SID socket #7.

Exciting!!!!!




a|x

[Wilba]

You'll notice you only see one line on your display, because the setup_mb6582.hex expects a 4x20 character LCD.

You can change setup_mb6582.asm and recompile (make a new setup_mb6582.hex).
You want to change it to #define DEFAULT_LCD_LINES 2

Quote

That 7th SID socket is still not working, though, annoyingly. Anyone any ideas how I should troubleshoot this? I'm now getting a tone from the socket is I connect pin 14 to pic 27 of SID socket #8, so the 1kHZ tone is not getting to socket #7, but nothing is arriving at the audio output. I don't know enough about the signal-path to know where the problem is most likely to lie. There don't seem to be any obvious soldering issues in this are- but then again, there may be issues that a more experienced solderer would notice immediately.

Can you go into more detail about how you troubleshooted this?
Break it down into specific tests... eg. testtone app, SIDs in sockets, #8 pass, #7 fail - testtone app, SIDs not in sockets, etc.
It sounds like you proved the audio buffer for #7 is working and that it's just a SID in socket #7 that doesn't output sound through that audio buffer.

[toneburst]

Hi Wilba.

Thanks very much for getting back to me again!

Quote

You'll notice you only see one line on your display, because the setup_mb6582.hex expects a 4x20 character LCD.

Yeah, I noticed that. I'm not too concerned about that, as this is just a temporary screen for debugging. I have a 20x4, but got impatient trying to make up the cable, found this old 20x2, and thought I'd use that, just for testing.

Quote

Can you go into more detail about how you troubleshooted this?
Break it down into specific tests... eg. testtone app, SIDs in sockets, #8 pass, #7 fail - testtone app, SIDs not in sockets, etc.
It sounds like you proved the audio buffer for #7 is working and that it's just a SID in socket #7 that doesn't output sound through that audio buffer.

It's definitely not a SID issue, as I've never put a SID in that socket. My testing so far has consisted of

• Insert 4x Core chip
• Upload SID Testtone application to all 4 Cores
• Connect Pins 14 and 27 of each (empty) SID socket in turn

All sockets output audio tone on left/right channels of each pairs audio output, except SID socket #7

• I then tried connecting pin 14 of SID socket #8 to pin 27 of SID socket #7
No audio output
• Then I reversed the procedure, connecting pin 14 of socket #7 to pin 27 of socket #8, and this time got an output from the left channel of output 4.

Soo... I think it must be a problem with the output stage of SID socket #7. Unfortunately, I'm an electronics dunce, so I don't really know how to go about testing the various components in this part of the circuit. I do have a simple multimeter, but I'm ashamed to say, beyond simple voltage tests, I don't really know how to use it. I can't see any obvious bad soldering around this area of the board, but I could well be missing something.

a|x