SF1ROM help?

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guitarzombie
Posts: 164
Joined: Sat Dec 07, 2013 6:18 pm

SF1ROM help?

Post by guitarzombie » Sun Jan 11, 2015 1:57 pm

Im making a Super Mario Unlimited and my bases loaded is an SF1ROM, not SFROM. But the chip says LD-0, so its not another revision or something. Wired it up, cant get it to boot.

Im using a 27c301 for the prg and just a regular 27c256 for the CHR. The 301 only needs one wire (pin 2 to gnd) but cant figure out whats up. But I cant find any information on this specific board. Anyone have any experience with this board?

lidnariq
Posts: 9680
Joined: Sun Apr 13, 2008 11:12 am
Location: Seattle

Re: SF1ROM help?

Post by lidnariq » Sun Jan 11, 2015 3:14 pm

SF1ROM is very similar to SLROM-04 and newer. (Edit: can't direct link to NesCartDB image pages)

You've most likely got some other mistake such as a bad connection or something, nothing specific to SF1ROM.
Last edited by lidnariq on Sun Jan 11, 2015 10:46 pm, edited 1 time in total.

guitarzombie
Posts: 164
Joined: Sat Dec 07, 2013 6:18 pm

Re: SF1ROM help?

Post by guitarzombie » Sun Jan 11, 2015 3:48 pm

Hrm, ok ill double check. Chips came out without a break in the traces, and only 1 wire to solder.

*EDIT*

I dunno, i think its the board somehow.

I pulled out the chips and they verified. Resoldered, even put in new chips. Same deal

guitarzombie
Posts: 164
Joined: Sat Dec 07, 2013 6:18 pm

Re: SF1ROM help?

Post by guitarzombie » Sun Jan 11, 2015 10:17 pm

Luckily I saved the chips for this SF1ROM and it looks like the PRG is listed as LD-2 and the SFROM board looking on the cart db is listed as LD-1 and the SFEXROM version is LD-0. 3 different types of chips, where as the CHR for each is always LD-0.

This leads to me as I suspected that the PRG pinout is different for each of these. Now I gotta figure it out, unless someone has already decoded it :P

lidnariq
Posts: 9680
Joined: Sun Apr 13, 2008 11:12 am
Location: Seattle

Re: SF1ROM help?

Post by lidnariq » Sun Jan 11, 2015 10:45 pm

Since SF1ROM appears to be a singleton for just Bases Loaded ... sorry

guitarzombie
Posts: 164
Joined: Sat Dec 07, 2013 6:18 pm

Re: SF1ROM help?

Post by guitarzombie » Sun Jan 11, 2015 11:37 pm

Well I got curious and decided to go with my hunch about the PRG being different aaaaaaaaaand...

:Trumpet fanfare:

looks like its a standard JEDEC/eprom pinout!

It has an MMC1B1-H, so I cross referenced the pinout with the nes edge pins and the mmc1 pinout and looks like

a16 is prg pin 2
a17 is pin 30 and the
/oe is pin 24 (connected to mmc1s pin 5)

everything else checked out.
Could this be the only NES officially released game with a 128K+ size that follows a standard JEDEC pinout? Its hard to tell cuz bases loaded's prg is 256 so its 32 pins already.


And just to see that I was 100% right, since I still had the original LD-2 chip, I opened up my burner and read the chip under the 020 setting. I even then split the Bases loaded rom, and verified the spit roms PRG with what was on that chip.

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