A Custom Kazzo

[TrendMend]

Hey there, so with the amazing help of InfiniteNESLives and the very helpful Kazzos txts I created a quick and dirty Kazzo replica in Eagle CAD that I plan to customize for my team (got one together!). Now since I sourced these parts from a local store they might be a bit harder to get from one supplier, but it is very easy to change out. Stupid me also ran out of protoboards and my breadboards seem to have gone missing (I think I actually used them for finished projects, whoops ) so I can't test it until I pick them up when I am up there, right now everything looks good to me, but I am running on 3 days of no sleep. You can check it out in the links below.

Connector: https://www.digikey.ca/product-detail/e ... -ND/770547
Github page: https://github.com/TrendMend/NESKazzo

P.S: I prefer Gitlab but for the simplicity sake, I have chosen Github.

[krzysiobal]

* M2 is not connected to a pin that can physically generate PWM pulses so you won't be able to control it at proper speed and during time that USB communication is in process
* Why the need of additional 74574? Atmega has almost enough pins to control everything using its own I/Os (one extra pin would be needed but you can merge PPU /A13 and CIRAM-A10 into one pin by resistor)
* I never personally needed to read value of CIRAM /CE, but in case you really need to know that, same trick as above need to be dode with second pin.
* Dont draw schematic with so many wires like that, it's better to use buses and labels - it is totally unreadable for first sight (that's my personal opinion)
* NES connector you used has pitch of 2.54mm, should be 2.50mm
* No protection of CPU and PPU data busses with resistors can cause shorts in case of bus conflicts or for carts that does not take care of PPU /RD

[Ben Boldt]

* NES connector you used has pitch of 2.54mm, should be 2.50mm

I always thought it was strange they used metric 2.50mm in regions that use inches, and 0.1inch (i.e. 2.54mm) in regions that use metric... It might almost work but you're definitely asking for trouble if you use a 2.54mm for your 72-pin slot.

You can get these 72 pin 2.50mm edge connectors cheap on AliExpress, no need to harvest from Game Genie or try to chop up a front load ZIF connector. I have had great luck with Kingworld, I have ordered many times from them. Once they sent the wrong item and they fixed it for me.

https://www.aliexpress.com/item/32827561164.html
They also have bulk pricing: 10pcs, 100pcs.

[TrendMend]

You can get these 72 pin 2.50mm edge connectors cheap on AliExpress, no need to harvest from Game Genie or try to chop up a front load ZIF connector. I have had great luck with Kingworld, I have ordered many times from them. Once they sent the wrong item and they fixed it for me.

Thanks for that tip, I will take a look at that today and make another part in Eagle CAD for it.

* M2 is not connected to a pin that can physically generate PWM pulses so you won't be able to control it at proper speed and during time that USB communication is in process
* Why the need of additional 74574? Atmega has almost enough pins to control everything using its own I/Os (one extra pin would be needed but you can merge PPU /A13 and CIRAM-A10 into one pin by resistor)
* I never personally needed to read value of CIRAM /CE, but in case you really need to know that, same trick as above need to be dode with second pin.
* NES connector you used has pitch of 2.54mm, should be 2.50mm
* No protection of CPU and PPU data busses with resistors can cause shorts in case of bus conflicts or for carts that does not take care of PPU /RD

I'll make all the necessary changes, the reason most of this is this way, is I quite literally copied the kazzo's schematic and replicated it in Eagle CAD for me and others to work off of. I will take a look at removing the 74564.

* Dont draw schematic with so many wires like that, it's better to use buses and labels - it is totally unreadable for first sight (that's my personal opinion)

I know I know, it is just me being stupid haha, it's been years since I've touched Eagle CAD, think of this as me getting the hang of things again. This redesign really threw me off as well. I'll update it sometime today.