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Hello,

Anyone got the shematic on hand to wire an SL1ROM as a SLROM specifically for the CHR side? I got a bunch of SL1ROM boards but the current limits of the 64k of CHR data is not enough for what Iwant to
do with them as I will be using 1meg chips with them.

Thanks In Advance!

Looks as though the big difference is the SLROM lacks the '32 set of OR gates that the SL1ROM has aside from the CHR size difference.

Interestingly I checked one of my SL1ROM games Monster Party and turns out my version is actually a SLROM when all 3 of bootgod's are SL1ROM.

I've gone through and reverse drawn the circuit for SLROM previously but not SL1ROM. I do plan to, perhaps I'll do it sooner vice later if you could make use of it.

It looks as though only one of the OR gates is actually used. I'm a little confused though you're saying that SL1ROM is limited to 64k (byte I assume) and you want to put 1meg (bit i assume ie 128KByte)

But it appears all SL1ROM boards are 128KByte (1Mbit) according to bootgod's data base anyways. So it would appear SL1ROM normally uses 128KByte like you're wanting it to... What do you have that only has 64k?

infiniteneslives wrote:
But it appears all SL1ROM boards are 128KByte (1Mbit) according to bootgod's data base anyways. So it would appear SL1ROM normally uses 128KByte like you're wanting it to... What do you have that only has 64k?

I was just going off of a readout I had that said SL1ROM could only handle 64k of CHR data on a 28 pin chip and it also has no lines for the extra address lines of a 32 pin chip and that was the major difference from it compaired to SLROM which has 32 pin CHR and PRG onboard.

Mainly I was looking to use some SL1ROM boards I have out of a pile of Operation Wolf carts I have to make up a copy of New Ghostbusters 2j and\or Adventure Island 4j but as they sit SL1ROM could only handle a 28 pin 27512 and I need to use a 32 pin 27010 as the CHR data of GB2 and AI4 are both 128k (1meg).

I had no idea if it was as simple as routing the highest addy to 5v or if there was alot more too it and I was hoping someone else like yourself might have already done this board modification in the past and I could save myself the headache of trying to figure it on my own.

Yeah there are both 32 pin and 28pin versions of the 128KB ROMs, the 28pin version uses every last pin while the 32 pin has some unused pins tied to Vcc and whatnot. Making that work should be just a matter of matching up the address and enable lines are connected properly.

But the other issue is that extra OR gate that slapped in on the SL1ROM board. I don't know the details of what it's doing as I haven't drawn out the circuit yet, but I'm sure it'll prevent SLROM games from working. Not sure about that though, it may depend on the game. Unless there was a SL1ROM and SLROM version of Monster party that game works on both boards apparently.

If it something you're not willing to take on yourself I could help you out. I converted a UNROM to UOROM and TSLROM to TSROM for @coinhaven. In return he let me keep the repro I ended up making. I took scans of the board and description of how to make the change so he could replicate it. Speaking of I need to post those up here for others to see also.

infiniteneslives wrote:
But the other issue is that extra OR gate that slapped in on the SL1ROM board. I don't know the details of what it's doing as I haven't drawn out the circuit yet, but I'm sure it'll prevent SLROM games from working. Not sure about that though, it may depend on the game. Unless there was a SL1ROM and SLROM version of Monster party that game works on both boards apparently.

That must be true as IIRC I've pulled normal SLROM and SL1ROM boards out of Operation Wolf carts. Be it that operation wolf was coded that way to avoid the extra OR gate I don't know.

nintendo2600 wrote:

infiniteneslives wrote:
But the other issue is that extra OR gate that slapped in on the SL1ROM board. I don't know the details of what it's doing as I haven't drawn out the circuit yet, but I'm sure it'll prevent SLROM games from working. Not sure about that though, it may depend on the game. Unless there was a SL1ROM and SLROM version of Monster party that game works on both boards apparently.

That must be true as IIRC I've pulled normal SLROM and SL1ROM boards out of Operation Wolf carts. Be it that operation wolf was coded that way to avoid the extra OR gate I don't know.

I guess the answer could be found by comparing dumps between the two.

infiniteneslives wrote:
I guess the answer could be found by comparing dumps between the two.

I'm gonna just wirewrap a mapper 1 game with 128k chr onto the SL1ROM board and see how funky things get. Right off the hop the extra 74HC32 presant on the SL1 VS the SL has cought my eye. I'll report back with any news worth while.

OK I did a little more looking around and I found out that the extra 74HC32 on the SL1ROM is actually to combine A13 and RD of the CHR data into one enable signal on the smaller 28 bin 128k chips nintendo used instead of having them seperate as they are on a 32pin 128k chip. Funny they have a 32pin PRG slot but not for the CHR and they added an extra chip to keep to the 28 pin form factor on the CHR side. They must have had an excess of 28 pin chips or something I dunno.

I just took apart the last 3 Operation Wolf carts I own and I did finally find one that is on a normal SLROM versus this dreaful SL1ROM but after finding out that the 74HC32 is combinding the signals from A13 and RD of the CHR chip I doubt dumping the chips is worth while. I'm near possitive the code will be the exact same on 32pin CHR chip from the SLROM vs the 28pin CHR chip on the SL1ROM cause it looks to be a hardware modification here not a software change of any sort. I will still dump them if anyone is intrested in compairing the code for shits and giggles.

Needless to say, This is getting a little out of my league now trying to figure out how to get a 32pin 27c010 onto a SL1ROM but if anyone else does figure it out I'd love to see a diragram and\or a schematic of how to do it.

That's interesting. I would be curious if the dump is the same although based on what you're saying it really shouldn't be. I'm curious why they would make the two different boards. Perhaps you're right about excess chips or something, but they still have the added cost of the '32.

The wiring should be fairly straight forward. Just connect all the corresponding pins. You'll have to lift pins or cut traces but you should be able to just copy the SLROM setup. Bypass the single OR gate that's being used if you want, apparently that the only difference between wiring on the two boards. If you're confused about the control signals post pics of the pinouts and I'll explain here.

My real concern is space though... It doesn't look like a 32pin ROM will fit in there those ROMs are so close to eachother, and the CHR ROM will end up extending to far into the PRG ROM I'd think. You might be able to try a trick I've done before to get more space inside a controller. You can basically put the CHR ROM on the BOTTOM of the board. The trick is you'll have to bend all the pins on the CHR ROM up instead of down like they are naturally. You'll basically be mirroring the pinout of the ROM to match the mirrored pinout on the bottom of the board. That way the PRG and CHR ROMs can over lap with the PRG ROM on top of the board and CHR ROM on the bottom.

infiniteneslives wrote: My real concern is space though... It doesn't look like a 32pin ROM will fit in there those ROMs are so close to eachother, and the CHR ROM will end up extending to far into the PRG ROM I'd think. You might be able to try a trick I've done before to get more space inside a controller. You can basically put the CHR ROM on the BOTTOM of the board. The trick is you'll have to bend all the pins on the CHR ROM up instead of down like they are naturally. You'll basically be mirroring the pinout of the ROM to match the mirrored pinout on the bottom of the board. That way the PRG and CHR ROMs can over lap with the PRG ROM on top of the board and CHR ROM on the bottom.

Oh it will fit but just barely. There is a resistor between the CHR and PRG that I already put on the back of the board too. They will be a VERY snug fit but it will due.

Operation Wolf versions are identical ROM data:

SL1ROM
SLROM

I remember expecting them to differ because the SLROM CHR was stamped as a higher version. Apparently changing ROM package warranted a new version number in this case. There are a few other cases like this as well.

BootGod wrote:Operation Wolf versions are identical ROM data:

SL1ROM
SLROM

I remember expecting them to differ because the SLROM CHR was stamped as a higher version. Apparently changing ROM package warranted a new version number in this case. There are a few other cases like this as well.

Thanks for the answer on that, I figured you'd be the guy in the know.

infiniteneslives wrote:
Thanks for the answer on that, I figured you'd be the guy in the know.

infiniteneslives I've sent you a PM with the scans you said you needed.