4 - quattro compilation in one cartridge
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4 - quattro compilation in one cartridge
Hello, I would like to put 4x quattro compilation in one cartridge. One rom batch takes 256KB, that is 4 x 256KB = 1MB = eprom 27C801.
I learned that from the four rom batches you need to delete the header and then merge into one file.
The problem is how to connect a 4-position slide switch to achieve what is shown in the video:
https://www.youtube.com/watch?v=Ge6sbccpynM
I would like to add that PCB BIC-58 does not require modification of EPROM connections, because it is an unofficial cartridge. Of course, the original flooded eprom must be mechanically removed.
Everything is based on mapper 232.
As if he did it on two switches for lines A18 and A19, then four combinations: 00, 10, 01, 11. According to scheme A18 not connected, A19 is VCC. Where to put the signal from lines A18 and A19?
I learned that from the four rom batches you need to delete the header and then merge into one file.
The problem is how to connect a 4-position slide switch to achieve what is shown in the video:
https://www.youtube.com/watch?v=Ge6sbccpynM
I would like to add that PCB BIC-58 does not require modification of EPROM connections, because it is an unofficial cartridge. Of course, the original flooded eprom must be mechanically removed.
Everything is based on mapper 232.
As if he did it on two switches for lines A18 and A19, then four combinations: 00, 10, 01, 11. According to scheme A18 not connected, A19 is VCC. Where to put the signal from lines A18 and A19?
Re: 4 - quattro compilation in one cartridge
What you need to do is control the ROM's A18 and A19 inputs with the two switches.
If the switches you have are specifically SPDT 3-pin "break-before-make", then connect ground to one side, +5V to the other, and the center pins to the ROM's two address lines.
If you have a 2-pin SPST switch, connect ground to one side, the other pin to the ROM's address line and ALSO a 5k resistor to +5V.
If it's some other kind of switch, tell me what it is and I'll help.
If the switches you have are specifically SPDT 3-pin "break-before-make", then connect ground to one side, +5V to the other, and the center pins to the ROM's two address lines.
If you have a 2-pin SPST switch, connect ground to one side, the other pin to the ROM's address line and ALSO a 5k resistor to +5V.
If it's some other kind of switch, tell me what it is and I'll help.
Re: 4 - quattro compilation in one cartridge
According to the PCB diagram, line A18 - does not connect to PCB, while line A19 is VCC. I will raise the A18 and A19 EPROM legs, but tell me where should these lines go from the switch to the PCB?
Is it enough to control the lines A18 and A19 in eprom? Don't the lines have to connect to the PCB or the mapping device?
If I would like to use one 4-level switch, which one?
Is it enough to control the lines A18 and A19 in eprom? Don't the lines have to connect to the PCB or the mapping device?
If I would like to use one 4-level switch, which one?
Last edited by mwolstein on Mon Jun 06, 2022 3:16 am, edited 2 times in total.
Re: 4 - quattro compilation in one cartridge
Lines A18 and A19 to be outside the PCB? I marked in the green rectangle.
Re: 4 - quattro compilation in one cartridge
Yes, that. Make sure you're using the right kind of switch - the words "break before make" are important. ... Either that or just make sure you never toggle the switches while it's on.
Re: 4 - quattro compilation in one cartridge
Two switches of this type. And if I would like to do it on one 4 level switch, what type?
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Re: 4 - quattro compilation in one cartridge
Almost anything could be made to work? Depending you might need some resistors and/or diodes.
Re: 4 - quattro compilation in one cartridge
You might be able to get away with connecting all the pins you labelled "0" to ground and all the pins you labelled "1" to +5V.
I'm worried about that switch not being a "break-before-make" sort - in that case, instead of directly connecting the pins to +5V, instead short all the "1" pins together and connect that via a 4.7k-ish resistor to +5V.
I'm worried about that switch not being a "break-before-make" sort - in that case, instead of directly connecting the pins to +5V, instead short all the "1" pins together and connect that via a 4.7k-ish resistor to +5V.
Re: 4 - quattro compilation in one cartridge
"break-before-make" ? so there should be a break before changing positions?
Is there a 4 way switch with a break before execution?
This 3-position STDP switch does this, because switching from left to right we make a wire.
Is there a 4 way switch with a break before execution?
This 3-position STDP switch does this, because switching from left to right we make a wire.
Re: 4 - quattro compilation in one cartridge
Yeah, "break-before-make" is a term you find on switches with more than one "closed" position that means exactly what you guessed. Importantly, it means that only the intended pins are ever connected.
If you can't find one, you can still work with it – you just have to use a pull-up resistor instead of explicit strong pull-up
If you can't find one, you can still work with it – you just have to use a pull-up resistor instead of explicit strong pull-up