Hey there once again!! As the title suggests, I want to build a reset based cartridge which means when you turn the cartridge on- the console selects the first game but when you push the reset button, it switches to the next one.
As far as I know a 74LS74 chips includes 2x D-type flip-flops which apparently can switch through up to 2 or 4 different games. I know how to use it in a 2-in-1 game cartridge, just connect it like that:
I can easily say this setup almost works. Well the only downfall of that is that when you turn the console on, it selects THE SECOND game right away but other than that the reset works perfectly fine. When you push reset, it switches to the first one and after you push reset once again, it runs the second game again and so on. What should I do to make the console run the first game right away??
My second and more serious problem is that I want to also build a 4in1 cartridge and as long as I'm concerned I can still use the 74LS74 in this case but how should I connect it??
But my biggest problem is that I also want to build a 8in1 cartridge and the 74LS74 is no longer useful in this case but apparently you can use a 4bit binary counter such as 74LS161/163.
So first of all, what's the difference between 161 and 163?? Second, how am I supposed to connect it in a FAMICOM cartridge?? Here's some schematics provided by @CallanBrown
Making sense of these 2 schematics, I tried to connet my 74LS161 chip to my custom 8in1 cartridge this way (assuming that I use 8 different games with size 512KB each, the chip has to control 3 higher addresses A19, A20 & A21):
After that it results the cartridge doesn't work.... Well technically it works, when you turn the console on, it shows the first game but when I push the reset button, it rarely switches through and when it does, it selects a random game but most the time it doesn't do anything.... What should I do to make it work?? Any kind of help or suggestions will be strongly appreciated!! Big thanks in advance!!
As far as I know a 74LS74 chips includes 2x D-type flip-flops which apparently can switch through up to 2 or 4 different games. I know how to use it in a 2-in-1 game cartridge, just connect it like that:
I can easily say this setup almost works. Well the only downfall of that is that when you turn the console on, it selects THE SECOND game right away but other than that the reset works perfectly fine. When you push reset, it switches to the first one and after you push reset once again, it runs the second game again and so on. What should I do to make the console run the first game right away??
My second and more serious problem is that I want to also build a 4in1 cartridge and as long as I'm concerned I can still use the 74LS74 in this case but how should I connect it??
But my biggest problem is that I also want to build a 8in1 cartridge and the 74LS74 is no longer useful in this case but apparently you can use a 4bit binary counter such as 74LS161/163.
So first of all, what's the difference between 161 and 163?? Second, how am I supposed to connect it in a FAMICOM cartridge?? Here's some schematics provided by @CallanBrown
Making sense of these 2 schematics, I tried to connet my 74LS161 chip to my custom 8in1 cartridge this way (assuming that I use 8 different games with size 512KB each, the chip has to control 3 higher addresses A19, A20 & A21):
After that it results the cartridge doesn't work.... Well technically it works, when you turn the console on, it shows the first game but when I push the reset button, it rarely switches through and when it does, it selects a random game but most the time it doesn't do anything.... What should I do to make it work?? Any kind of help or suggestions will be strongly appreciated!! Big thanks in advance!!