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[Help] Dualbios and STV-Multicart

Yippikaye

Yippikaye

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Hi there,

I was wondering if there is a compatibility (or not) between a dualbios and Darksoft's STV-Multicart.

I received the other day a dualbios that I installed correctly but I have a black screen and nothing shows on the screen (no sound either)

Everything works fine with my original bios (but I dont have access to all the games because of region limitation)

So I would like to know if there is something to deal with the STV-Multicart or miisalo Game Selector ?( ??!

Thanks in advance for your help ;)
 
Is is the multibios on right eprom type? Did your board have eprom or mask rom and what is the type of the eprom the multibios is in? 27C4xxx?

Edit: So you have dual bios that has switch, not the multibios? In that case you have now 27c800 eprom? If pin 1 of the eprom socket is connected to the ground, your mobo is not compatible with 27c800, it should use 27c4096/27c4100 pin order and I don't think there is eprom having that and 8mbit capacity. That would explain the problem
 
Last edited:
miisalo said:
Is is the multibios on right eprom type? Did your board have eprom or mask rom and what is the type of the eprom the multibios is in? 27C4xxx?
Click to expand...
Here some pictures (better than my explanations)


DSC_0195.JPG
 

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Take a picture of the multi bios where we can see the chip numbers.

Most ST-V use 27c400 eproms but I see a 27c4096 eprom installed on the pcb.
 
EDIT: actually it should work if dual bios is 27c800

I was looking for the wrong datasheet. 27c800 is compatible with 27c4096
 
Mitsurugi-w said:
Take a picture of the multi bios where we can see the chip numbers.

Most ST-V use 27c400 eproms but I see a 27c4096 eprom installed on the pcb.
Click to expand...
The dualbios is a 27C800
And the one working on the motherboard is a 27C4096
 
Damn, I did not look it wrong, 27c4100 would be compatible with 27c800 but 27c4096 is not.
 
Here is the 27c4096 (and 27c4100) datasheet, check the pinout.

http://pdf.datasheetcatalog.com/datasheet/macronix/MX27C4096PC-10.pdf

Now compare it to the 27c800 (http://static1.squarespace.com/stat...6eee4b03e44bada1c3d/1414817535529/M27C800.pdf) . If you compare the 27c4100, they are the same from bottom up, 21 = 20, 20 = 19 .... and then pin 1 is used for bank switching. But 27c4096 uses different pinout, you would need to swap most of them.

Just get multibios instead, I actually might have one on 27c4096, I can send it to you.
 
miisalo said:
Here is the 27c4096 (and 27c4100) datasheet, check the pinout.

http://pdf.datasheetcatalog.com/datasheet/macronix/MX27C4096PC-10.pdf

Now compare it to the 27c800 (http://static1.squarespace.com/stat...6eee4b03e44bada1c3d/1414817535529/M27C800.pdf) . If you compare the 27c4100, they are the same from bottom up, 21 = 20, 20 = 19 .... and then pin 1 is used for bank switching. But 27c4096 uses different pinout, you would need to swap most of them.

Just get multibios instead, I actually might have one on 27c4096, I can send it to you.
Click to expand...
Let's do so :D
 
I have a dual BIOS japanese/modbios on a 27c800 and no problem with DS STV-multicart. I have legs 1 and 42 outside the socket and 1+22+31 to the switch.
 
It seems that there is different types of eeproms used
My motherboard needs a 27C4100 or 27C4096 (same pinout)
Once I receive the new modbios I'll let you know ;)
 
Gakman said:
I have a dual BIOS japanese/modbios on a 27c800 and no problem with DS STV-multicart. I have legs 1 and 42 outside the socket and 1+22+31 to the switch.
Click to expand...
27c800 works fine if ST-V board is a version that used 27c4100 eprom or mask rom. But there are other boards that use 27c4096 that has different pinout (I example have both kind of boards). Only way to use dual bios with those are to piggyback two 27c4096 and control chip enable pins with a switch. Modbios is much easier solution because it is just using same eprom chip.
 
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