Hi everyone. I´m new to NGCD and want to built a switchless mod inside it, like in a Saturn. As the NGCD has no reset button, I´m using Pin 20 on the 68k cpu for a reset signal and as a reset button I use a little tactical-switch. I´m using seb's code from the Saturn and done a light modification to it, cause 50 / 60 Hz is inverted and the system needs a reboot to set it, also for the language. I connected the green pad (here in there picture) for 50 / 60 Hz switching. I connected J1 and J2 green pads (here in the picture) for language switching. As for japanese language there will be no switch, cause when every jumper is open, it is set to japanese. I tested every function first with only cables, no chip. 50 Hz when tied hi, 60 Hz when tied low. J1 Usa when tied low or J2 when tied low, J1-J4 tied to nothing will be japanese. Pin 20 on the 68k cpu tied low, the console resets. I tought, ok, nice, now with the PIC16F630 and the light modification of seb's code. And I strictly ran into some problems. 50 / 60 Hz switching won't work, it's always 60 Hz. For the language switching, it is always Usa (or EUR), I don't know, cause it is both in english. What am I doing wrong?
Have you measured the output pins on the pic to ensure they are at the correct logic level? Its possible your modification isnt working correctly and the outputs are just stuck at what you describe
nope, haven't measured it by now. I now used the light modificated seb's code by wolfsoft for the AES. Now I only connected J1 and it works switching between USA and JAP mode. But still the Hz switching isn't working. I think I don't mind when 50 / 60 Hz switching is not working...cause 50 Hz sucks, no one wants to see black beams on top and bottom of the screen, so FU that xD I seated the tactical-switch in the disc drive, right end corner. You don't see it directly, even if you open the lid Hope ths is a mod for everybody to have fun with btw Here is the code: https://dl.dropboxusercontent.com/u/26577053/neogeo_dual_for_RGB_LED.zip And here some pictures: USA mode JAP mode the little tactical-switch No case modifications were necessary !
As someone who built a shift register yesterday using one of those switches to fake a clock signal they're absolutely terrible at doing their job. I also hope you've put in a pull down resistor on the switch. Or pull up as the case might be.
They work OK, but (like a lot of things) you have to be aware of their limitations. The first is that they have a rather limited current carrying capacity (typically something like 50mA) the second is that they also have a MINIMUM switching current (something like 10uA), and if you try to use them in circuits where they are switching less than this they slowly develop more and more contact bounce and finally stop working entirely. Finally, a new recently manufactured switch from a good manufacturer like ALPS will probably no produce any contact bounce at all - but don't let that fool you into thinking you can get away without it. After a few years, that same switch might be generating several ms of bounce - especially if you are using it in a circuit with very low switching currents.
So is the idea to push down on the back left corner of the CD lid? So hold it down as it cycles or the like?
No, the idea was not to do any case modifications to the console, so it is left in its original shape. The switch will not be pushed by the lid, you have to open the lid to push the button. I think it is the best way to do so and it is reversible, if you want to sell it again. No ugly dpt switch on the outside of the console !
Ah I see, I thought there might be enough movement in the hinge of the lid to allow for actuation of a typical tactile button.