Jump to content

Core-reboot problem


Flemming

Recommended Posts

I have two cores that does not work properly, i've tried all the (few) tricks i know to get them to behave - first i thought that their problem was similar, but when i hooked them up with an LCD i could see that they behaved each in their own way.. i sincerely hope that someone inhere can spot my booboos so i can complete my dreammachines

To not confuse matters i will ofcourse only describe one core in this post :)

The problem:

The core reboots sporadically... well, if the core is all alone it reboots pretty consequent, almost rythmical. if the core is connected to a SID module and an LCD it reboots less often (may be because the LCD and SID module drains some current or something). The strange thing is that if i lightly rest a finger or two on top of the PIC the core stops rebooting

The situation in general:

The core works so to say.. i can upload mios apps to it (tested the ID-changer app and mbsid app) and when the core is connected to a SID module i can play notes via MIDI between reboots. I soldered two SID modules and the core reacts the same regardless of which SID module is connected... also i can see the standard text in the LCD 'T. Klose, mbsid v0.30 - CS not connected' (or something), with each reboot the LCD first briefly shows the MIOS version number and then quickly goes to the 'mbsid'-text

The PSU:

I actually have three C64 PSUs and they all drive my first build just fine (http://www.audiosonic.dk/private/midibox/), they all give out the same readings on my multimeter, and they all give the same result with the faulty core - my dream was to add 1core/2SID to the box in the pictures to get 2 stereo parts.

The physical facts:

I measured the core's voltage and it gives me 5V all the right places - i went straigt for the solution without the VREG (connecting the C64 PSU's 5V directly to where the VREG was supposed to sit) which is the way i made my exsisting mbsid work. I checked that i did not misplace any discrete components, and i even ran over the whole board resoldering every joint to make sure there is proper connection... i must admit that i did not fit all the header pins as this was supposed to be a slave-core, but that shouldn't cause any problems as far as i'm informed. I also tried to connect the 5V to J2 instead, but it's the same deal

If someone can give me some suggestions to where i may find the error i will be happy as hell and start fixing stuff instantly :)

Link to comment
Share on other sites

Warning - while you were reading a new reply has been posted. You may wish to review your post.

Well, anyway:

Are you using a machined socket? If not, you might want to use one between the socket you have soldered in and the PIC (the pins of the socket are thicker than those of the PIC, so that might do the trick).

Link to comment
Share on other sites

Yeah, right, i meant those...

It maybe would have been an explanation for the less frequent rebooting, when other modules are connected..

Hmm, could it be that they were damaged somehow? Man my multimeter is not fancy enough to measure caps i'm sure, but i never experienced one that wimped out on me... still, i'm open to all suggestions!!

Link to comment
Share on other sites

The strange thing is that if i lightly rest a finger or two on top of the PIC the core stops rebooting

If that's not a dodgy connection or dodgy part, it's almost surely a problem with ground connections. (Your hand being an antenna, as opposed to your hand being a mounting assistant)

You are doing your testing with ONLY the core module connected right? No SID modules or anything?

Link to comment
Share on other sites

(Your hand being an antenna, as opposed to your hand being a mounting assistant)

I'm pretty sure you're right, and i also think i found out the booboo; the female 7pin DIN connector i used to plug in the C64 psu to maybe did not allow proper ground connection, everything works now :) and i even stuffed the parts into my existing mbsid with no problems... pictures will be available later :)

Link to comment
Share on other sites

  • 4 months later...

Hi Ben

What i learned is that even if we're talking a single-core setup, you have to respect the MB-CAN stuff!!! Have a look at this schem

http://www.ucapps.de/midibox_sid/mbsid_v2_communication.pdf

if you look at core1 you see an extra diode (1N4148) between D2 and D3 on J15 - you will also see a 1K resistor between D3 on J15 and Vd on J2

After i soldered the resistor and the diode (i just stuck them on the backside of the PCB) i had no more grief.... ever! These are only needed for MB-SID, and it is used to link cores together to achieve the lovely 8-SID setup, nevertheless even if you have only 1 core, the diode/resistor needs to be fitted anyway!! Note that other users i talked with have had their MB-SID running just fine even if they did not fit the parts for CAN - I have no idea what makes the difference!

If you already fitted these parts then just ignore the above and cross your fingers that someone else has a solution that will get you running ;)

Link to comment
Share on other sites

Flemming i take it this extra diode and resistor differs to ones that are right next to the opto, and which are included in the kit?

My single core, single sid setup is working *almost* perfectly,

when i change the note while a drum engine is being sequenced, the sound tends to go screwy, all most circuit bent.

Normal patches work fine, but the Techno PWM patch seems a bit noisey, so im thinking its the patches which use modulation,

or a certain connection to the core like CLK, or another pin(s).

I wonder is it because i havent these extra components its happening.

but then again,

theres being plenty of people who have had no problems after completing a kit,

without using any extra parts, so that kind of throws that out the window too!

LOL

Link to comment
Share on other sites

Howdy!

The diode and resistor that Flemming mentioned in the above post, are part of the CAN bus interface and connected via J15 and J2 ;

http://www.ucapps.de/midibox_sid/mbsid_v2_communication.pdf

As I have not yet constructed MIDIbox SID V2 (still running V1 here, with one SID6581 ), I can only speculate.  But I did notice Techno PWM and some other patches didn't sound right.  As you put it "noisy"  My 6581's came as pulls from various working and non functioning C-64's.  I replaced a 2484 dated 6581 with a 6581R3 datecode 0786 (S?).  Long story short, it sounds much better.  I also have an R4 another R3 and a few with no rev. no. after the 6581.  If you have another SID, I'd give it a try.  But do the CAN bus additions and let us know how it goes.

Dean

aka

Scam

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...