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Hi!!

I want to build a cartridge with original Holy Diver . I think, it is possible to do on an UNROM board. But, I don't know what's really needed to build a cartridge..... Can someone tell me about this??? Or can someone make a full pinout??? I will be very thankful!!!

As I suggested to you in private, with a UNROM board (Max PRG Size of 128Kb) the game will run. There are two other things you need which will require modding the UNROM board. You need CNROM style CHR switching using D4,D5,D6,D7. Then you also need Mirroring Control by D3, 0 = Horizontal Mirroring, 1 = Vertical Mirroring.

WOW!!! I recorded an original holy diver PRG on my EPROM 128KB, I've started it on my UNROM dev-cart and i can really play it!! But with crappy graphics, of course . But, I don't really understand you..... CNROM can address max 32KB CHR and there is a full pinout of CNROM board: and there is D0, D1, D4 and D5 connected from 74LS161 but to the PRG ROM. So, can someone make a full pinout, how to connect CHR ROM???

You should probably add another 74LS161 to the UNROM cartridge and connect it like in that diagram except you need to use PRG D4, D5, D6, and D7. Then connect CHRA13, A14, and under those two I imagine you should put CHR A15 and A16.

That should get you most of the way there. The only other thing to do is work out mirroring. I'm not sure how you could control that with a 74LS161 but it can be done. All I can say is Holy Diver expects D3 as the mirroring bit. Maybe someone else can give you more info.

i thought this was mapper 1? why not just use a SLROM board. they are very common

I think it was hacked to use mapper 1. It's probably easier to use the hacked version than to modify the hell out of the board.

tokumaru wrote:I think it was hacked to use mapper 1. It's probably easier to use the hacked version than to modify the hell out of the board.

YES, but, this version is buggy....

The MMC1 hack I did has two issues. One is somewhere a bug exists that prevents the player from using the Twin Fireball magic and causes problems with the first boss and possibly after that. I could probably fix it but there's another issue which is massive slowdown because the game had very little free processing time free to begin with. Normally it takes quite a bit of action to cause slowdown but when using a mapper like mmc1 or mmc3 the time spent writing to registers is too much. I might be able to optimize it a bit but it seems to me it would be easier to just modify UNROM to work like mapper 78.

YEAH!!! Big thanks guys!!! I connected CHR with another 74LS161 from this diagram, but to PRG i connected D4, D5, D6 and D7 pins .

Now I made a dev-cart. If something will be wrong, I will rewire this .


(this is a pirate famicom cart with UNROM board )
And original IREM's holy diver really works with graphics!!!

But..... on the first level graphic is crappy.......

so, how to control the mirroring??? Please, help me, I will be VERY thankful!!!

There should be H and V pads on the board which are shorted together for Vertical or Horizontal mirroring. You'll have to take the signal from these pads and figure out how you hook it up to one of the output bits on the LS161. D3 is supposed to be used to switch mirroring on Holy Diver. When D3 is = 0 it is Horizontal Mirroring, when 1 it is Vertical Mirroring.

I do not fully understand mirroring on the hardware level as far as what is going on so I can't really speculate how you use the D3 bit to set mirroring. Other members will though.

The only discrete mapper with a mirroring switch that I know of is A*ROM, which uses single-screen mirroring. One would need a mux to implement MMC1/MMC3 style mapper-controlled mirroring.

Why the need to create a repro in the first place, is the original hard/expensive to find?

its japan only

In that case, why the need to repro instead of importing an authentic cartridge and breaking open a R.O.B. cartridge for the NES-JOINT adapter?