Lavar
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ne7 wrote:

Lavar; heya – a real good place to get  cheap components is Ebay smile search worldwide + be creative in what you look for on there (like searching 'in' listings) and you’ll have maybe 3 to 5 of each part for the price you’d pay for one in radioshack or maplins (not sure if you have those in Belgium) smile

RG; I’m beginning to think this is all tied to the Famicom’s lack of a CIC security chip and differences to the way the two machines initialise data – the reason PR8 might not be resetting is very likely related to this, I’m going to grab LFT next time I see him online and pick his brains (I warned him already hehe) about it as if anyone can shed light on anything h/w related its most probably him *Grin*

Neil; I repeated the steps in my guide and built yet another PR8 cart for Famicom in the interim so the Famicom side of things checks out just fine – we just have to poke around a bit more on the NES side, it's super weird but I'm sure we'll get to the bottom of it smile

Apologies for the delay getting back on here - work getting in the way of fun *Grin*

We don't have maplins or radioshack, but the Ebay items have been way cheaper than other Belgian electronics stores.  Can't believe I didn't try Ebay. Also, just to be shure, would these parts work?

SRAM
PRG EPROM
Schmitt Trigger Hex Inverter IC

Last edited by Lavar (Apr 14, 2012 6:49 pm)

ne7
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UK
Lavar wrote:

SRAM
PRG EPROM
Schmitt Trigger Hex Inverter IC

Hey Lavar - those will work just fine :)
\o_

RG
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Milwaukee, WI

Any word on the NES cart issues? Nesdev decided to ignore the thread.

ne7
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UK

Hey RG, I have not had a chance to do any more digging unfortunately; should have some more spare time over the next few weeks tho so I'll take look at it with some fresh eyes *fingers crossed* can get to bottom of it :)

TSC
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Milwaukee, WI

@RG (Will) + anyone else: The power switch workaround doesn't apply with a pin4-disabled NES. As you may already know, the unit doesn't blink when this pin is disabled.

TSC
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Milwaukee, WI

I hate to be this guy, but...

Telerophon
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Austin, Texas

I wish I could help you, TSC, but I'm very new to NES Dev and the NES cart hardware spec. I hope we figure it out, though. smile

derekb
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I commented in my FS thread and sold an NTRQ cart to a member, I've never had any issues with NTRQ when using zelda carts as donors, fwiw

ne7
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UK

Having taken a look at this briefly for a 3rd time, I'm pretty sure that it is related to the type of MMC chip and board layout in use in Mario Golf, avoid said cart and I should think these problems should go away, I'm basing this on the fact that while I was away I did a little test using the Famicom version of Mario Golf and building a PR8 cart and it too misbehaved, no other Famicom carts did this (done a fair few tests now :) ...

Unfortunately I'm a bit lacking on the free time front and was really concentrating on getting them all working on the Famicom (which they do 100% btw :) Apologies for the late reply peeps \o_

Last edited by ne7 (Aug 28, 2012 5:26 pm)

derekb
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my understanding is that they used a couple diff manufacturers for the mmc chips and they behave slightly different between the makers, could be the issue with NTRQ on NES carts.

http://forums.nesdev.com/viewtopic.php?p=62546

derekb
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I just built another NTRQ using a Bard's Tale donor, working fine..

Last edited by derekb (Sep 1, 2012 1:22 am)

derekb
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for reference this is the cart I recently sold on the forums


you might notice the top picture has less wires, NTRQ actually only needs 2 wires to work properly since it is a 1mbit rom. Pin 30 is Not Connected inside of 1mbit chips, so there is no reason to wire it up. Pin 31 is not needed on SNROM boards. The only necessary wires are Pin 2 to Hole 24, and tying Pin 24 to GND (I use pin 16)

ne7
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UK

ah crumbs yes - I thought I had updated my guide with a note on this; you only need the extra wires if you are using larger 27c020 or 27c040 eproms and doubling / quadding the data (as they are for higher address lines) ... thanks for mentioning that Derekb \o_

TSC
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Milwaukee, WI

I decided to revisit this project. I have now tried on the Zelda and Bard's Tale carts with no luck.

I know the flasher works and soldering points are good because I managed to split the .nes/rom file of the carts used for the donor, extract the .prg, throw on a 020 and pop the eprom w/ wires to get the cart working again. For whatever reason NTRQ (and PR8/Pulsar) does NOT like the carts I provide, which all seem to be MMC1B2 and MMC1B3.

I am completely puzzled.

TSC
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Milwaukee, WI

OK, now this is fucking strange. I just tried a second Bard's Tale cart to see if I was losing my mind and it completely works. This makes two Bard's Tale carts with the same MMC1B2 chip, solid solder connections and working eprom...but one works and the other doesn't. Is there something else at play here?

TSC
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Milwaukee, WI

BREAKTHROUGH.

@derekb: I noticed after looking at your photos that both of your MMC chips had a larger font, while all the carts I made had a smaller font, despite the same MMC revision numbers. The one cart I managed to just get working had a larger font as well.  So then, what would happen if I removed the smaller font MMC from an NTRQ cart that didn't work and replaced it with a large font MMC from a completely different mapper/cart?

NTRQ now works on an NES Open Golf cart with the new large font MMC, despite being the same exact revision.

So after poking around bootgods site, I see that (according to the photos) the smaller font MMC chips are manufactured by NEC:

http://bootgod.dyndns.org:7777/profile.php?id=179

http://bootgod.dyndns.org:7777/profile.php?id=472

while the larger font MMC chips are manufactured by Sharp:

http://bootgod.dyndns.org:7777/profile.php?id=700

http://bootgod.dyndns.org:7777/profile.php?id=519

This is a little misleading however, because the photo/info on bootgod's site shows that NES Open Golf had an MMC manufactured by Sharp (large font) while any copy I have in my possession has an NEC MMC (small font). It also states Zelda had an NEC MMC as well:

http://bootgod.dyndns.org:7777/profile.php?id=703

http://bootgod.dyndns.org:7777/profile.php?id=173

So, having figured this out, it would seem as though it's luck of the draw when purchasing SNROM games. It's probably best to have a few spare Sharp MMC chips laying around if anyone is hardcore enough about not wanting to use Powerpak.

NOW the question is this: What is so different about the Sharp/NEC MMC chips that one works and one doesn't, despite having the same revision number? Furthermore, why is it that you can get an NEC MMC to work when using the power-switch-toggle-while-cart-is-in-the-NES-but-not-actually-pressed-down trick?

Perhaps you can short a pin to get it to work, instead of replacing the MMC outright?

Last edited by TSC (Oct 22, 2012 2:33 am)