I bought some "MOS 6502" from Chinamann. A CPU with data code 4384 or similar was shown, five pieces "MOS 6502 A" with data code "0222" (sic!) And five "MOS 6502AD" with data code "4285" came:
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Four of the five "4285" run in the VC-20, none of the other six; Interestingly, these all have the marking "ME15" or "ME16" on the underside:
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Despite an intensive search, I have not found anything about this marker. But it smells a lot like that these things all come from the same "(re) labeling factory".
Interestingly enough, they all ran in the NOP generator. So I plugged it into the VC-20 again and sniffed a little with the oszi - and lo and behold: there is activity on pin 36 ("NC" on the 6502)! : gruebelThrough a bit of research I learned that the 6502C ("Sally"), which was made especially for Atari, was exactly on this pin (a modified) R / W. So I cheekily bridged pins 34 and 36 and switched on the VC-20 and - tataaa! - he runs!
Sally has another / HALT input on pin 35 - yes, this is there too, the CPUs can be stopped by a GND on this pin. So it is apparently actually relabeled Sallys. (Very stupid to make "MOS6502" out of these, with Sallys a higher price would certainly be achieved. : rolleyes:).
So if anyone apparently got dead 6502 CPUs from China, it would be a good idea to check the marking on the bottom and / or to bridge pins 34 and 36 as a test. Maybe they're not dead at all.
You are a genius sir ! I have 3 "ME16" and one "ME15" and they all work in a VIC-20 by bridiging 34 and 36 !
Final stereo mod completed on SX-64 - second channel of MixSid is now 8580 instead of two 6581s. Nice contrast.
Here are pics of the front panel controls:
Goethe, forgot to mention, enjoyed your video - don't have a MSSIAH (yet) but I do have a midi interface (Sonus) for the 64 and a midi keyboard. hmm...
Good question - lol. I tend to mod first and figure out what to use it for later ... (I know kind of backwards ...)
BTW, I have a recommended mod for you - I noticed the SX-64 case being so crammed with electronic goodies that now with the MixSid and the Lumafix64 a lot of heat is generated in that top of the MPU board area. So I went into my 1980's parts bin and found a nice ball-bearing i486 cpu heatsink fan and I mounted it on top cover right above that area to exit the warm air out the top. I decided to use an external 12v brick power supply so as to not tax the SX-64 power supply further (even though the fan draw is only 150ma). Also didnt want to introduce any more possible electrical fan noise into the system
So why did I do it? Therefore: Because I thought it was cool to have a C64 voice on the piano ...: freak
Thanks to @Henning , I now have a "C64 piano", so to speak . : D
It currently sounds hideous.
Both my piano playing - not practiced for a long time, as well as the six-voice polyphonic MSSIAH standard sound in MIDI mode.
However, I hope that you can tweak a lot.
Have not yet found whether and if so how to teach the MSSIAH other SID instruments for MIDI mode.
This will be a long learning curve, however, so that it can play pleasant-sounding C64 music. But I'm excited to see "what's possible"![External Media: [media] [media]https://youtu.be/IP9dJ7yp3E4][/ media] [/ media]
Additionally now the pictures of the installation:
It was necessary to insert an intermediate base between the MixSID board and the already soldered SID base.
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Even then, the MixSID board is still too low and is only just above components.
So I put a shield in between. Possibly. you could leave them out if you pull in a second intermediate base instead. But I had concerns that it might become too unstable or that there would not be enough space in the direction of the floppy, so I decided to do so.
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Connections for A5, A8 and I / O1 (I need them for my MSSIAH for $ DE00 addressing) can be tapped at:
on Pin3 -> A5 and
on Pin23 -> A8
UC1 - Pin 10 is I / O1
UD1 and UC1 are practically directly opposite the MixSID board on the underside, so that you only need very short cables.
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I then equipped the MixSID with the SID from the SX-64 and a second "von Halde" -
As you can see, I also just provided the CPU with a heat sink (ingenious @GMP clamp method). To do this, it is unfortunately necessary to bend a metal tab in the housing slightly inward, otherwise there is not enough space for the heat sink.
And as you can not see, I have of course also renewed the cooling paste from VIC (even a ceramic model with gold pins).
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I also equipped the SIDs with heat sinks using the ingenious @GMP clamp method
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Everything put together and - sits, fits, wobbles (not) and has air!
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Cable routing and locking - the "thick" black is a stereo headphone cable.
I did not (yet)
dare to drill a hole in the housing, so I have currently led it beyond the module slot ... [attach = '130225', 'none', '2'] [/ attach]
... secured against accidental
train damage [attach = '130226', 'none', '2'] [/ attach]
Your-SX64 now has a MixSid twin on the other side of the Atlantic
Works great just need to do the final front panel storage compartment switches for the mode / SX spkr on / off / stereo mini jack and a 8 position blue dip switch for the mixer / io and priority jumpers)