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Thread: MV2F only Crosshatch

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    MV2F only Crosshatch

    Hi guys... I have 3 MV2F boards with same issue..

    - solved all previous problems and tesed with Neo Diagnostic Bios and "all tests passed" but...did not read the carts and stay in Crosshatch..

    - I have cleaned the slots and tried with few carts
    -cecked the traces of A1-A19 from the slot to NEO-GO

    any suggestion please

    THANKS

  2. #2
    Morden's Lackey
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    What I normally do in this case is use unibios and put a cart in. At unibios's crosshatch screen there is an option to do the memory viewer, pick that then scroll down to 000100. At that location, on a working cart, you should see "NEO-GEO".

    https://www.mvs-scans.com/misc/IMG_0474.jpg

    On yours the "NEO-GEO" will likely be corrupt in some way. Use that corruption to point you in the direction of the issue.

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    Quote Originally Posted by ack View Post
    What I normally do in this case is use unibios and put a cart in. At unibios's crosshatch screen there is an option to do the memory viewer, pick that then scroll down to 000100. At that location, on a working cart, you should see "NEO-GEO".

    https://www.mvs-scans.com/misc/IMG_0474.jpg

    On yours the "NEO-GEO" will likely be corrupt in some way. Use that corruption to point you in the direction of the issue.
    thanks bro will try tomorrow and will make some photoes for more help

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    Quote Originally Posted by ack View Post
    What I normally do in this case is use unibios and put a cart in. At unibios's crosshatch screen there is an option to do the memory viewer, pick that then scroll down to 000100. At that location, on a working cart, you should see "NEO-GEO".

    https://www.mvs-scans.com/misc/IMG_0474.jpg

    On yours the "NEO-GEO" will likely be corrupt in some way. Use that corruption to point you in the direction of the issue.
    I started with two of them and have had a different response..
    one have noting....no letter at all and the otherone have two "E" of the NEO GEO.....

    How can translate now those messages...
    Thanks

    140459714_785421708679014_1463422061134735739_n.jpg
    140685390_1085577645280770_3080445759554199150_n.jpg
    Last edited by paoloMVS; 01-20-2021 at 02:29 AM.

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    Morden's Lackey
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    The first one, maybe a address lines issue or the cart roms aren't getting enabled. Can you scroll down some more and see if you get any non-zero data.

    The 2nd one, data bit 14 is stuck high.

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    Quote Originally Posted by ack View Post
    The first one, maybe a address lines issue or the cart roms aren't getting enabled. Can you scroll down some more and see if you get any non-zero data.

    The 2nd one, data bit 14 is stuck high.
    thanks ack I solved the first one changing the NEO-GO @G2.5...now read the cart perfectly..

    About the second one... thanks for the advice...but how can now go on and ceck the data bit 14

    TIA

  7. #7
    JammaNationX
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    Quote Originally Posted by paoloMVS View Post
    thanks ack I solved the first one changing the NEO-GO @G2.5...now read the cart perfectly..

    About the second one... thanks for the advice...but how can now go on and ceck the data bit 14

    TIA
    I’m assuming data bit 14 on the VRAM. Each ram has 8 bits, lower vram is 1-8(D0-D7) and upper vram is 9-16 (D8-D15).

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    JammaNationX
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    Actually I can’t remember if VRAM bits are reversed from WRAM, either way check the data lines.

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    Quote Originally Posted by Xian Xi View Post
    I’m assuming data bit 14 on the VRAM. Each ram has 8 bits, lower vram is 1-8(D0-D7) and upper vram is 9-16 (D8-D15).
    2k or 32k vram....

    Thanks

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    I believe the issue is with data bit 14 (prog A19) of the cart slot. If the bit was a stuck high in vram/wram the diag bios would have caught it. I assume its happening on both slots, so I think it will likely either be whatever IC sits between the slots' PROM data lines and the CPU or a trace between that IC and the CPU.

    https://wiki.neogeodev.org/index.php...rtridge_pinout

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    Quote Originally Posted by ack View Post
    I believe the issue is with data bit 14 (prog A19) of the cart slot. If the bit was a stuck high in vram/wram the diag bios would have caught it. I assume its happening on both slots, so I think it will likely either be whatever IC sits between the slots' PROM data lines and the CPU or a trace between that IC and the CPU.

    https://wiki.neogeodev.org/index.php...rtridge_pinout
    I follow the prog A19... that goes on pin 41 of the NEO-EO @E/G3 ....

    (https://wiki.neogeodev.org/index.php?title=NEO-E0)

    now I have to go on to pin 38 and follow it till the CPU ???

    thanks

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    Quote Originally Posted by paoloMVS View Post
    I follow the prog A19... that goes on pin 41 of the NEO-EO @E/G3 ....

    (https://wiki.neogeodev.org/index.php?title=NEO-E0)

    now I have to go on to pin 38 and follow it till the CPU ???

    thanks
    Sorry, I see the confusion. When I said prog A19 I meant pin 19 on the A side of the prog board, which carries data line 14.

    Doing a couple probes it looks like D14 is wired up using this pin mapping

    SLOT 1 PROG PIN 19 <=> NEO-G0 @ H2.5 PIN 45
    SLOT 2 PROG PIN 19 <=> NEO-G0 @ H2.5 PIN 55
    NEO-G0 @ H2.5 PIN 49 <=> 68K PIN 55

    I didn't test all pins but looks like the pinout of that NEO-G0 matches this

    https://wiki.neogeodev.org/index.php..._J4_pinout.png

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    Thanks ack.. will try tomorrow the PROG line.

    Meanwhile a take a small video of the third MV2F that I have stucking in Crosshatch... this one make a different thing...the NEO GEO is complete at address 0000100 but it's like flickering...

    thanks


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    Quote Originally Posted by paoloMVS View Post
    Thanks ack.. will try tomorrow the PROG line.

    Meanwhile a take a small video of the third MV2F that I have stucking in Crosshatch... this one make a different thing...the NEO GEO is complete at address 0000100 but it's like flickering...

    thanks

    I haven't see that before. What happens if you only have a cart in slot 2? and if there are carts in both slots?

    One possibility could be the PIN 51 (DS0) and/or PIN 39 (DS1) of the NEO-G0.

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    Quote Originally Posted by ack View Post
    I haven't see that before. What happens if you only have a cart in slot 2? and if there are carts in both slots?

    One possibility could be the PIN 51 (DS0) and/or PIN 39 (DS1) of the NEO-G0.
    thanks ack... what schould I ceck on DS0 or DS1...

    I mean where have them to go or came from or I have to ceck the state with logic probe...

  16. #16
    JammaNationX
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    Check the schematics on NG Development Wiki.

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    Quote Originally Posted by ack View Post
    Sorry, I see the confusion. When I said prog A19 I meant pin 19 on the A side of the prog board, which carries data line 14.

    Doing a couple probes it looks like D14 is wired up using this pin mapping

    SLOT 1 PROG PIN 19 <=> NEO-G0 @ H2.5 PIN 45
    SLOT 2 PROG PIN 19 <=> NEO-G0 @ H2.5 PIN 55
    NEO-G0 @ H2.5 PIN 49 <=> 68K PIN 55

    I didn't test all pins but looks like the pinout of that NEO-G0 matches this

    https://wiki.neogeodev.org/index.php..._J4_pinout.png
    ack !!! You was perfectly right...was pin 55 of the 68k not connected...now read perfeectly the cart
    THANKS !!!

    Still working on the third MV2F...the one with NEO GEO flickering01
    Last edited by paoloMVS; 01-23-2021 at 08:35 AM.

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