Need Saturn multitap schematics

Unable to find a Saturn multitap down here, and put off from buying one over the net by outrageous importing taxes, me and a friend started thinking about the possibility of building one on our own.

But I found no data on build a Saturn multitap, or any console multitap, after skimming through google for a while, so I came here to ask the great oracles 'o eletronics, if a making a homebrew multitap is possible, of it has nasty custom chips in it?


Established Member
I have no idea because I don't have one...

Just out of interest, where in the world are you?


Established Member
Buy one online. Err---tell your government it's for medicinal purposes.

Ok I opened up one of mine...

There's a black chip that says Sega on it, with a bunch of purple shit:




5D1 Japan

The top has three chips that say:

(M) MC74HC257N


That's about all that's on the multitap. I wonder if my bomberman multitap is identical...
er... wouldn't the HD404448A40H number on the first chip designate it's a Hitachi chip (I have, for instance, a LCD controller called HD44800 or something by Hitachi I think), so it should be possible to get the non-Sega version of it.

The second chip is prolly just some 74XXxxx logic IC, they're ubiquitous - so technically you *could* get the chips (if my assumption about the first one is correct) but then you'd have to wire 'em together in some way.

Alternatively, maybe you can find some developer's doc about how the Saturn sees the multitap and then engineer your own using that information... guess you'll need a PIC of some sorts for that but I'm no expert...


Extra Hard Mid Boss
The multitap has to have some intelligence in it, see the SMPC manual for some info.
Thanks for all the info. I'll do some research in the Saturn dev docs to see if it's possible, without getting even more expensive than just buying one of those online.

I'll also check the possibility of adapting other console's multitaps.


Established Member
And where are you going to get the controller jacks from? Tell me your not planning on canibalizing three saturns for one, $2 (Toy's R Us
), multitap?


Established Member
I'm totally clueless when it comes to building electronic stuff other than PCs, but wouldn't the parts and everything cost more than actually buying one?
Originally posted by slinga@Jun 26, 2003 @ 12:02 AM

And where are you going to get the controller jacks from? Tell me your not planning on canibalizing three saturns for one, $2 (Toy's R Us :D ), multitap?

Ah, I can find those, along other Saturn parts for pretty cheap. I know a console cematary in my city where I can canibalize those :)


$2? Serious? Oh well, but it's useless, since the shipping would cost $20 anyway...


Established Member
Yeah I bought 3 multitaps from Toy's R Us a while back for $2 each. I'm sure there all gone by now anyhow. Seriously where in the hell do you live that shipping would be so expensive? Japanese people sell stuff all the time, I'm sure someone's selling a multitap (assuming that shipping from the US is too expensive...).
I live in a place where I have to pay a 60% fee over product value AND shipping for anything I import by mail as an individual, unless it's printed material (magazines, books, newspapers), or medicines that are not avaliable over here yet.

Ah, and the customs have the bad habit of guessing the produc value out from their asses, mostly when it comes to used stuff, unless I got some kind of viable coupon/document attached to it that tells it's value (and they sometimes ignore such paper, if it's not that visible of it they are not in a good mood).

So the $2 buck multitap would end up being $35. Considering my current economical sucake level, that's quite some money.

So, if building it myself can be any cheaper than that, I'm in.


Staff member
From a skimming of the relevant sections in the SMPC manual, homebrewing a multitap seems feasible. However, I can't just hand you a set of working schematics because of the need for intelligence (i.e. a program) that antime mentioned. Basically it would be necessary to develop new multitap hardware/firmware. This is not as hard as it sounds, but it's not trivial either. I can help you with it if you're willing to go through the trouble of actually building/testing the unit and are willing to accept the possibility of failure. The SMPC manual gives quite a bit of information about how the protocol works, but it's not at the level where I can give much assurance that the first attempt at implementing it would be compatible.