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PostPosted: Fri Mar 23, 2018 9:29 pm 
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Joined: Fri Mar 23, 2018 8:58 pm
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We all know that some games require the MIC functionality. But it is not available on AV Famicom nor on NOAC Famicom clones.
According to this schematic,Image
The MIC signal has two paths:
The analog signal is sent and mixed with the audio output, so that we can hear the voice we speak to the MIC from the audio output. Reviving this part of circuit can be easily achieved.
The digital signal is sent to a Three-state Hex Reverter, controlled by /INP0 (named as /OE1 on wiki) of CPU, and then D2 of CPU. Reviving this part of circuit is also not difficult on AV Famicom since we can get all we want.
But it is not possible to get the /OE1 of CPU on an NOAC. So the signal can not be controlled.

Anybody has any ideas?


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PostPosted: Fri Mar 23, 2018 9:36 pm 
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Location: NE Indiana, USA (NTSC)
How is NOAC sending clock pulses to the controller? Does the low-level mode of allpads show that $4016 D2 is open bus, or is it driven low?


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PostPosted: Fri Mar 23, 2018 10:32 pm 
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tepples wrote:
How is NOAC sending clock pulses to the controller? Does the low-level mode of allpads show that $4016 D2 is open bus, or is it driven low?

Sounds a good idea! I'll try this and see if it works. Thank you very much!


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PostPosted: Sat Mar 24, 2018 4:09 pm 
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Location: Poland
In two different famiclones that I've fixed there was problem with non-working joypad.
What I did was to add special CPLD board which decodes $4016/$4017 access into generatng strobe/clock signal and puttind the data bit from joypad connector into cartridge data bus.

It worked, so if you put data bits onto data bus when accessing $4016/$4017, NOC's CPU will read them.

Image Image


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PostPosted: Sat Mar 24, 2018 4:45 pm 
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Location: Canada
Do NOAC systems have parallel controller inputs, serializing them internally?


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PostPosted: Mon May 21, 2018 9:10 am 
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tepples wrote:
How is NOAC sending clock pulses to the controller? Does the low-level mode of allpads show that $4016 D2 is open bus, or is it driven low?


Your allpads is mapper0?
However there is no CHR in the ROM.


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PostPosted: Mon May 21, 2018 9:14 am 
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Location: NE Indiana, USA (NTSC)
Haruka wrote:
Your allpads is mapper0?
However there is no CHR in the ROM.

This and RHDE: Furniture Fight use mapper 0 + CHR RAM. If you can't modify an NROM board to use CHR RAM, you could run it on any UxROM, BxROM, or AxROM board.


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