I planned to make a multiregion N64 ages ago. I followed the D4S diagram, which he has since disowned as the contr_gate & contr_dat lines need switching also. I could build an auto switching circuit triggered by an lm1881 monitoring the c-sync, which stays low when in the wrong region. The problem is what IC to use for switching the pif data lines. Relays are out of the question. With 13-ish lines to be switched the circuit would be monstrous, not to mention the power drain. To make things simple, take a look at this diagram I cobbled together: What IC would be ideal to toggle between the 2 controllers (to DATA I/O), making use of the trigger? A useless circuit to build, but the solution can be applied to the pif.
I don't understand what you're doing, where do the controllers come into play? Aren't you switching NTSC and PAL PIFs? Can you post d4s' old diagram to correct?
Here's the link to the original diagram: http://www.assemblergames.com/forums/showpost.php?p=291185&postcount=7 The controllers don't come in to play, other than to show a very basic example of what i'm stuck at: toggling between two bi-directional data lines without resorting to relays. Sorry, i've got a habit of over-complicating things! As you put it much clearer, I want to switch between a PAL & NTSC pif, but am unsure which IC would be best.
Switching off an IC's supply doesn't isolate it, that is probably the real reason he disowned it. As I said in that thread, I don't really think they are bidirectional signals. If I'm right you only need to multiplex them (must know each signal's direction), and for that you can use 74AC157. If the signals really are bidirectional or you can't find out, you can weakly pull up (10K) all signals regardless of direction and use bus switches though it's almost as inelegant as the original diagram, except it's safe. I can't recommend a specific bus switch though as they aren't standardized from vendor to vendor, most likely whatever you can get will be suitable.
Thanks Calpis, that gives me a good starting point. I'm only assuming that some of the data lines may be bi-directional, as the controller data line is, but i may be wrong. Going back to d4s' mod that I tried a while ago, the only problem I had was the controller was sluggish/intermittant. Switching the contr_dat/gate pins fixed that, so his mod was on the right track. Once (not if!) I get this working, i'll post pics and a crystal clear diagram. Cheers. Edit: Found old pics from a year ago, just before I gave up in favour of the xbox slim. To save space, I mounted the the PAL PIF straight onto the NTSC one, after separating the legs to be switched. http://bobzee.multiservers.com/console/n64/autoregion.htm
