Schematic for UM6561?
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Schematic for UM6561?
Well first of all HAPPY NEW YEAR
I want to make a mini Famicom clone by using UM6561 + two EPROM so that I can run simple NROM games on it.
I am testing the circuit on a breadboard :
I found a Dendy schematic which is based on UM6561 but it seems it has some errors in it :
(capacitor signs are Russian : MK=uF / H=nF / n=pF)
Fortunately I have a Famicom clone named FUMA-001 which uses the same chip :
By comparing them I found out that their circuit is very different so I have to compare them with another famous Famicom schematic :
Also I want to omit RF and its related parts so that the whole thing become more compact.
I want to make a mini Famicom clone by using UM6561 + two EPROM so that I can run simple NROM games on it.
I am testing the circuit on a breadboard :
I found a Dendy schematic which is based on UM6561 but it seems it has some errors in it :
(capacitor signs are Russian : MK=uF / H=nF / n=pF)
Fortunately I have a Famicom clone named FUMA-001 which uses the same chip :
By comparing them I found out that their circuit is very different so I have to compare them with another famous Famicom schematic :
Also I want to omit RF and its related parts so that the whole thing become more compact.
Last edited by FARID on Thu Jan 05, 2017 2:02 pm, edited 1 time in total.
Re: Schematic for UM6561?
Dendy :
Fuma :
Famicom :
80sFREAK :
Output :
console5.com :
Output :
Fuma :
Famicom :
80sFREAK :
Output :
console5.com :
Output :
Last edited by FARID on Sun Jan 08, 2017 10:17 am, edited 2 times in total.
Audio
- Attachments
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- Sample_Music_Dendy.zip
- (955.52 KiB) Downloaded 537 times
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- Sample_Music_Fuma.zip
- (673.19 KiB) Downloaded 528 times
Last edited by FARID on Wed Feb 01, 2017 8:42 am, edited 4 times in total.
Re: Schematic for UM6561?
7805 official datasheet suggest to use 0.1uF and 0.33uF but in Dendy and Famicom they used 47uF and 470uF :
Dendy :
Fuma (it seems caps are swapped wrongly?) :
7805 Datasheet :
Dendy :
Fuma (it seems caps are swapped wrongly?) :
7805 Datasheet :
Re: Schematic for UM6561?
Dendy (suggests to use 470nF (=0.47uF) Electrolytic capacitor) :
Fuma (uses 100nF Ceramic capacitor) :
Famicom (suggests to use 0.47uF Electrolytic capacitor) :
so which one should I use?
Fuma (uses 100nF Ceramic capacitor) :
Famicom (suggests to use 0.47uF Electrolytic capacitor) :
so which one should I use?
Re: Schematic for UM6561?
Famicom :
Dendy (both caps for crystal are 30pF) :
Fuma (Caps are different 39pF and 12pF) :
Dendy (both caps for crystal are 30pF) :
Fuma (Caps are different 39pF and 12pF) :
Re: Schematic for UM6561?
I've seen different specified capacitances there, depending on the nature of the input voltage and the technology of the capacitor.FARID wrote:7805 official datasheet suggest to use 0.1uF and 0.33uF but in Dendy and Famicom they used 47uF and 470uF :
Larger capacitances are needed when you have full- (or half-) wave rectified AC and the capacitor has to hold enough power to keep everything running for up to 10ms between mains.
On the low side, a better ESR will improve AV quality.
On the 2A03 (I can't speak for the Dendy parts), the reset pin has a depletion NMOS pullup inside. When I measured mine, that pin emits somewhere between 20 and 50 µA continuously, only vaguely a function of the output and supply voltages.FARID wrote:Dendy (suggests to use 470nF (=0.47uF) Electrolytic capacitor) :
Fuma (uses 100nF Ceramic capacitor) :
Famicom (suggests to use 0.47uF Electrolytic capacitor) :
so which one should I use?
The choice of capacitor only determines how long the CPU is held in reset after power up or after the user presses the reset button. A larger value will take longer.
The specific value doesn't seem to matter much, as long as the CPU comes out of reset consistently.
Re: Schematic for UM6561?
It works fine :
https://youtu.be/P-ByTSWdE84
Schematic Rev 2 :
- Better circuit for Video output
- Fixed some mistakes
Suffix info :
UM6561F-1 - NTSC
UM6561F-2 - PAL-B
UM6561F-3 - PAL-M
UM6561F-4 - PAL-N
Source : http://www.emu-land.net/forum/index.php ... #msg959563
https://youtu.be/P-ByTSWdE84
Schematic Rev 2 :
- Better circuit for Video output
- Fixed some mistakes
Suffix info :
UM6561F-1 - NTSC
UM6561F-2 - PAL-B
UM6561F-3 - PAL-M
UM6561F-4 - PAL-N
Source : http://www.emu-land.net/forum/index.php ... #msg959563
Last edited by FARID on Fri Dec 20, 2019 9:10 am, edited 1 time in total.
Re: Schematic for UM6561?
I designed a PCB for my new project (United Famicom = Famicom + TxROM)
Which parts should be separated because of noise?
Which parts should be separated because of noise?
Re: Schematic for UM6561?
Most of the system is low-speed 5V digital, and thus pretty immune to any kind of crosstalk.
However, the analog signals—audio and video—are quite sensitive. Coax is probably overkill, but you wouldn't go wrong with the PCB equivalent (ground traces on both sides of the signal, and ground fill underneath)
However, the analog signals—audio and video—are quite sensitive. Coax is probably overkill, but you wouldn't go wrong with the PCB equivalent (ground traces on both sides of the signal, and ground fill underneath)
Re: Schematic for UM6561?
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- PCB & Schematic..zip
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- krzysiobal
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Re: Schematic for UM6561?
What's the point of making so long traces (GND polygon pour underneath helps from getting noise?)
How do u metalize holes?
How do u metalize holes?
Re: Schematic for UM6561?
At first I wanted to use SMD to DIP adapter but later I decided not to use it and solder the chip directly to the main board, that is why that part seems a little awkward.What's the point of making so long traces
Jero on nesdev IRC channel gave me two pdf regarding how to mix analog and digital parts to reduce the noise.GND polygon pour underneath helps from getting noise?
I didn't make the PCB at home, and as I said it costed 50$.How do u metalize holes?
- Attachments
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- Mixed analog and digital.pdf
- (988.36 KiB) Downloaded 535 times
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- Mixed analog and digital 2.pdf
- (182.76 KiB) Downloaded 483 times
Re: Schematic for UM6561?
Thanks for the schematics Farid. I do have a question though can the UM6561 be used in a NTSC system if I select a different crystal?
Re: Schematic for UM6561?
Sorry I have no idea about it.muramasa wrote:Thanks for the schematics Farid. I do have a question though can the UM6561 be used in a NTSC system if I select a different crystal?
But I can test it if you give me the proper info.