Neo-Geo Technical Documentation

Discussion in 'Game Development General Discussion' started by andoba, Oct 14, 2007.

  1. andoba

    andoba Site Supporter 2014

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    There is any? That concers, pinouts, hardware documentation, programming information... Any information is welcome.

    I'm talking about the cartridge system. Thanks.
     
  2. Blur2040

    Blur2040 Game Genie

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    Well, cart & CD are pretty much the same system...but I'd suggest going to www.neo-geo.com

    There are a few people there who do in fat develop for it.
     
  3. Calpis

    Calpis Champion of the Forum

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    There's very little tech information at the neo-geo forums, I'm sort of in the same boat. If you want to develop for it, obviously learn 68K and how tiles/bitplanes work then look at different emulator source code and their respective development forums. If you want to know how the hardware REALLY works, not in an abstract way, you'll have to figure it out yourself because nobody else has really comprehensively documented the Neo Geo, I've looked!

    Pinouts are nonexistent except for a partial MVS PROG board pinout by Charles Macdonald which I can't find at the moment.

    I've made a pinout for the home system but it's meaningless if you don't have the logical schematics since there's a lot more to a Neo cart than ROM. In other words Neo carts cannot be expressed through a pinout like many consoles can.

    Example:
    Code:
    A1	GND			B1	GND
    A2	GND			B2	GND
    A3	p.13	D0		B3	p.9	A0
    A4	p.15	D1		B4	p.8	A1
    A5	p.17	D2		B5	p.7	A2
    A6	p.19	D3		B6	p.6	A3
    A7	p.22	D4		B7	p.5	A4
    A8	p.24	D5		B8	p.4	A5
    A9	p.26	D6		B9	p.3	A6
    A10	p.28	D7		B10	p.2	A7
    A11	p.14	D8		B11	p.40	A8
    A12	p.16	D9		B12	p.39	A9
    A13	p.18	D10		B13	p.38	A10
    A14	p.20	D11		B14	p.37	A11
    A15	p.23	D12		B15	p.36	A12
    A16	p.25	D13		B16	p.35	A13
    A17	p.27	D14		B17	p.34	A14
    A18	p.29	D15		B18	p.33	A15
    A19	nc			B19	p.32	A16
    A20	nc			B20	p.1	A17	a18
    A21	nc			B21	139.3		a19?
    A22	nc			B22	p.12	/OE	/a20?
    A23	A24			B23	B24
    A24	A23			B24	B23
    A25	+5V			B25	vcc
    A26	+5V			B26	vcc
    A27	+5V			B27	vcc
    A28	nc			B28	jumper to vcc
    A29	nc			B29	nc
    A30	nc			B30	nc
    A31	nc			B31	nc
    A32	nc			B32	7.3, 8.3, v1x.13 D0	7.2 (v1x.23 - A10) 8.2 (v1x.12 - A0)
    A33	nc			B33	7.4, 8.4, v1x.14 D1	7.5 (v1x.25 - A11) 8.5 (v1x.11 - A1)
    A34	3.3, 4.3, v2x.13 D0	3.2 (v2x.12 - A0) 4.2 (v2x.4 - A12)	B34	7.6, 8.6, v1x.15 D2	7.7 (v1x.4 - A12) 8.7 (v1x.10 - A2)
    A35	3.4, 4.4, v2x.14 D1	3.5 (v2x.11 - A1) 4.5 (v2x.28 - A13)	B35	7.11, 8.11, v1x.17 D3	7.10 (v1x.28 - A13) 8.10 (v1x.9 - A3)
    A36	3.6, 4.6, v2x.15 D2	3.7 (v2x.10 - A2) 4.7 (v2x.29 - A14)	B36	7.13, 8.13, v1x.18 D4	7.12 (v1x.29 - A14) 8.12 (v1x.8 - A4)
    A37	3.11, 4.11, v2x.17 D3	3.10 (v2x.9 - A3) 4.10 (v2x.3 - A15)	B37	7.14, 8.14, v1x.19 D5	7.15 (v1x.3 - A15) 8.15 (v1x.7 - A5)
    A38	3.13, 4.13, v2x.18 D4	3.12 (v2x.8 - A4) 4.12 (v2x.2 - A16)	B38	6.3, 5.3, v1x.20 D6	5.2 (v1x.2 - A16) 6.2 (v1x.6 - A6)
    A39	3.14, 4.14, v2x.19 D5	3.15 (v2x.7 - A5) 4.15 (v2x.30 - A17)	B39	6.4, 5.4, v1x.21 D7	5.5 (v1x.30 - A17) 6.5 (v1x.5 - A7)
    A40	1.14, 2.14, v2x.20 D6	2.15 (v2x.6 - A6) 1.15 (v2x.31 - A18)	B40	6.11, 5.11				5.10 (v1x.31 - A18) 6.10 (v1x.27 - A8)
    A41	1.3, 2.3, v2x.21 D7	2.2 (v2x.5 - A7) 1.2 (139.14)		B41	6.13, 5.13				5.12 (v1x.22 - /ce) 6.12 (v1x.26 - A9)
    A42	1.13, 2.13		2.12 (v2x.27 - A8) 1.12 (139.13)	B42	nc
    A43	2.4			2.5 (v2x.26 - A9)			B43	nc
    A44	2.11			2.10 (v2x.23 - A10)			B44	nc
    A45	2.6			2.7 (v2x.25 - A11)			B45	nc
    A46	2.9, 04.3, 3.9	(clk)	B46	04.01, 6.9, 8.9		(clk)
    A47	139.15		/V2e	B47	v1x.24			V11/12./OE
    A48	nc			B48	nc
    A49	GND			B49	GND
    A50	GND			B50	GND
     
    Last edited: Oct 14, 2007
  4. andoba

    andoba Site Supporter 2014

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    Well, I guess I'll get a loose home system and a cheap loose cart and look how does it work. :/

    Thanks!
     
  5. Calpis

    Calpis Champion of the Forum

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    That's what I did, it's the only way unfortunately. If you want to RE carts, start with very early games like Nam. The very first MVS games don't have ANY custom chips, but all home carts have at least one custom chip :(

    The key is to RE early (1991) MVS, early AES and compare middle (1994) MVS and AES and only examine late MVS/AES. It's also helpful to look at bootlegs which sometimes have already figured out custom chips.

    The difficulty is in the character multiplexer chip in AES systems and in the bankswitching chip used in games with more than 32M graphics. If you can figure those two chips out, you can easily make any normal Neo Geo cart. Beyond that there's only special bankswitching and protection methods for specific games.
     
    Last edited: Oct 14, 2007
  6. ASSEMbler

    ASSEMbler Administrator Staff Member

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    What about lapping the custom chip from a nam cart until you get to the
    construction? That's what they did for some ATI reverse engineering.
     
  7. Calpis

    Calpis Champion of the Forum

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    Yeah that's always a possibility, but then in that case you can just use official PCBs too... Using SNK chips is how all MVS->NGH converters were made until Neo Flash's, which may be why they were so expensive. I know the multiplexer chip can't be all that complex though, I think a $5 CPLD or a handful of TTL chips should be able to emulate it, same with the bankswitching. I just don't think anyone has bothered to RE it since it doesn't affect emulation in any way. If anyone has any clues about it I'd love to hear!
     
    Last edited: Oct 15, 2007
  8. madhatter256

    madhatter256 Illustrious Member

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    Trying to build a clone?
     
  9. andoba

    andoba Site Supporter 2014

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    Are you crazy? :rolleyes:

    I guess how much would cost to make a clone of that machine... :eek:h:
     
  10. Calpis

    Calpis Champion of the Forum

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    I'm not trying to make a clone, just 100% SNK dependent cartridges. I'd love to see some new games made for Neo Geo, I think it's one of the only consoles that stands a chance at getting new unofficial releases since the fanbase is so strong and willing to shell out.

    Hehe there actually are 1 slot MVS system clones! They are very recent and I think cost more than a legitimate 1 slot.
     
    Last edited: Oct 16, 2007
  11. cdoty

    cdoty Gutsy Member

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    You can visit my site:
    http://arcadedev.emuvibes.com for some programming information.

    Also, if you PM me your e-mail address I can send you the NeoGeo Spex pdf file from Pa-Pa-Panic, and mvstech.txt from Charles McDonald.
     
    Last edited: Nov 11, 2007
  12. Calpis

    Calpis Champion of the Forum

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    Little bump...

    Hehe recently I got a "1.2 million gate" FPGA which can certainly fit an entire Neo Geo with plenty of room to spare! The actual cost of this chip is only ~$15, but of course you'd have to add fast RAM, a lot of large memory to store ROMs (or a lot of chips to interface with a real cartridge) and a few high quality DACs. Time for reverse engineering/rewriting emulator code for hardware is the only factor now since we have the technology :D
     
    Last edited: Mar 21, 2008
  13. andoba

    andoba Site Supporter 2014

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    I think that interfacing with the cart would be cheaper... XD

    Gah, let's see when chinese stop doing famiclones and start doing Neoclones. :110:
     
  14. MottZilla

    MottZilla Champion of the Forum

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    You mean Neocloned home AES systems? Not going to happen. AES carts are expensive as fuck. The Famiclones work because NES and Famicom cartridges are cheap and abundent.

    As Calpis said, there are NeoGep MVS cloned PCBs now, but they cost more and they are cloned crap. :p Not really sure if they are crap but I'd rather official than a clone any day.
     
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