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Thread: 27C322 as a 32mbit V Rom

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    Hi XX,

    You can use macronix, I know that they are eeproms, but they work at 16 bit.

    Un saludo

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    Quote Originally Posted by fremen View Post
    Hi XX,

    You can use macronix, I know that they are eeproms, but they work at 16 bit.

    Un saludo
    So they can work as 8 bit for V roms?

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    Hi XX,

    Yes they work at 8 bit.
    MX29L3211

    Un saludo
    Last edited by fremen; 08-28-2012 at 04:20 PM.

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    Buyicnow

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    Yes, they are sop instead dip socket.
    But there are adaptors to convert sop to dip, and you need an adaptor for the programmer also
    Last edited by fremen; 08-28-2012 at 05:23 PM.

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    Are those chips only made in 3.3V?
    Clowns Suck


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    Quote Originally Posted by Xian Xi View Post
    How do I build a multiplexing circuit with two 74HC257 chips in order to use the 27C322 as a V rom?
    Use two 245 chips and one inverter. Map odd byte to one of them, even one to the other, drive A-1 to even bus /OE, /A-1 to even bus /OE.

    Should do the trick but it's going to be a big adapter.

    Edit:

    Checked 257, simpler design indeed, no inverter required.
    What you want should looks like this
    Last edited by Pedrobear; 08-29-2012 at 06:56 PM. Reason: MOAR

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    Necro bump

    Can you merge 16mbit Vroms onto 322s? ....like V1+V3=V1 and V2+V4=V2
    It seems like the Neo-PCM chip works as a multiplexer for the V roms.
    If I move the jumper to A20 on a progbk1 will 322s drop right in?
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    Hi,

    Quote Originally Posted by bustedstr8 View Post
    Necro bump

    Can you merge 16mbit Vroms onto 322s?
    Yes, but doesn't work correctly because 27C322 only works at 16bits.

    Quote Originally Posted by bustedstr8 View Post
    ....like V1+V3=V1 and V2+V4=V2
    No, V1+V2=V1 and V3+V4=V2

    Merry Xmas and Happy New Year

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    Quote Originally Posted by fremen View Post
    Yes, they are sop instead dip socket.
    But there are adaptors to convert sop to dip, and you need an adaptor for the programmer also
    so you also need to swap some pins no? because sop 44 have 2 pins more than dip 42 and some different pinouts? and they work on3.3v instead of 5v from neo pcbs? right?

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    Hi,

    Quote Originally Posted by jago View Post
    so you also need to swap some pins no? because sop 44 have 2 pins more than dip 42 and some different pinouts? and they work on3.3v instead of 5v from neo pcbs? right?
    Totally right

    Un saludo

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    Quote Originally Posted by fremen View Post
    Hi,



    Totally right

    Un saludo
    ok , unfortunately my programmer can't accept mx29l3211.
    i already tried sharp 28f320bjd-ttl80 which are normally 8 or 16 bit 32m but can't find the datasheet, and after test they don't work.

    what a plague for replace a 32m v rom!

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    Quote Originally Posted by fremen View Post
    Hi XX,

    Yes they work at 8 bit.
    MX29L3211

    Un saludo
    Can i program those with a TOP3000 programmer?


    Quote Originally Posted by fremen View Post
    Yes, they are sop instead dip socket.
    But there are adaptors to convert sop to dip, and you need an adaptor for the programmer also
    Do they need to be programmed before they go on the adaptors? Cause i see you can buy them allready on the adaptors as well.

    Do the adaptors lower the voltage to 3.3v or is there something else required?

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    Hi mate,

    Quote Originally Posted by NEO-GEO man View Post
    Can i program those with a TOP3000 programmer?
    Unfortunately top3000 doesn't support the MX29L3211

    Quote Originally Posted by NEO-GEO man View Post
    Do they need to be programmed before they go on the adaptors? Cause i see you can buy them allready on the adaptors as well.
    No, you can solder them in the adaptors then to programm them. The answer to XX about the programmer adaptor (not about the eeprom adaptors) was in order to use the programmer with another devices than MX29L3211 or to use the MX32L3211 for other pourposes

    Quote Originally Posted by NEO-GEO man View Post
    Do the adaptors lower the voltage to 3.3v or is there something else required?
    You don't need anything to lower the voltage during the programmation even if you solder the eeprom in the adaptor, the programmer take in to account that you're burning a 3.3v device, after yes, you need two diodes in line to lower the voltage since the carts provide 5v.

    Saludos
    Last edited by fremen; 01-10-2013 at 09:22 AM. Reason: clarifications

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    So it would be easier to split up the V ROMs and use 27C160 instead?

    How is that done?

    Is there any other 32Mbit chip that can run in 8bit mode?

    Can a 27C320 be used on those adaptors?
    Last edited by NEO-GEO man; 01-10-2013 at 09:13 AM.

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    Hi,
    Quote Originally Posted by NEO-GEO man View Post
    So it would be easier to split up the V ROMs and use 27C160 instead?
    Well, it's depend, if you're repairing 2x32V roms cart and have free slots to put 4x27c160 yes, but the problem is when you tray to repair 3x32V roms cart or 4x32V cart.

    Quote Originally Posted by NEO-GEO man View Post
    How is that done?
    I think you are refering to:

    32mb V1=V1+V2
    32mb V2=V3+V4

    Quote Originally Posted by NEO-GEO man View Post
    Is there any other 32Mbit chip that can run in 8bit mode?
    Should have, but I don't know.

    Saludos

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    I have a Pulstar MVS cart that needs a new V1 ROM.

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    Quote Originally Posted by fremen View Post


    Should have, but I don't know.

    Saludos
    What about the 27C320?

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    Hi,

    I've seen the 320 datasheet and it is equal to the 3211, so you can use the same adaptor (not the programmer adaptor) and swap the same pins in order to work like a 322. Beside, you have the advantage that it doesn't need to lower the voltage and it is supported by top3000 (only the SO 44 format). The main problem is to find them and to know the price.

    Saludos
    Last edited by fremen; 01-10-2013 at 10:21 AM.

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    Thanks! So it wouldnt be direct solder to the adaptor? Would i need to swap some pins around?

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    Hi,

    First solder the eeprom to the adaptor, then burn it and finally swap pins.

    About the MX23C3210, the 42 DIP format is equal to M27C322 so it doesn't need an adaptor but it is not supported by top3000.

    Saludos

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