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SD-1000 new Multicart for SC-3000, SG-1000 and MK III based on Pi Pico
Posted: Thu Apr 25, 2024 4:10 pm
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Hi,
i've just published my last DIY project for a Flash multicart based on raspberry "purple" Pi Pico clone. It's a simple and cheap project, i hope you'll like it! here's the link: https://github.com/aotta/SD-1000 |
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Posted: Thu Apr 25, 2024 5:09 pm |
Great job! |
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Posted: Fri Apr 26, 2024 2:47 pm |
Oh wow, that's really cool! | |
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Posted: Sun Apr 28, 2024 1:17 am |
A friend and I had a question regarding this statement:
Can you clarify exactly what this means?[/quote] |
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Posted: Sun Apr 28, 2024 8:25 am |
If you look for "rp2040 board" or "pico purple" on aliexpress you'll find several offers with different options: green ("original"), black or purple. The differences are not limited to the pcb colors, since the black has 4mb flash ram instead of the "standard" 2mb, and the purple clone has 16mb flash ram. The not green boards also have a usb-c connector instead of the older used by Raspberry and, most important, they exposed more gpio/pins for using in projects than the green. Only a couple, but really useful when you need 16 GPIO handling bus and 8 GPIO for data! ;) But, for having more pins with exposed GPIO, the black and purple board had to change a little the pinout, removing some GND pins and CHANGING THE PINOUT FROM THE ORIGINAL RASPBERRY PI PICO (you can note it on the attached pictures). So, in my SD-1000 i used the "purple" one. I'm pretty sure you could use also the "black" one (but i haven't tested it) for a multicart with only 4mb for storing games, but you CAN'T use the original PICO since it doesn't work and could be damage itself or your SEGA if used! |
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Posted: Sun Apr 28, 2024 9:05 pm |
Interesting, thanks. Also considering the Pico uses 3.3V logic on the GPIO pins, is there any level shifting being done so it's compliant with the 5V power from the host console? | |
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Posted: Sun Apr 28, 2024 9:34 pm |
No, i build first version with 4 sn74lvc245 as level shifter, but discovered that rp2040 is tolerant to 5v usually output by console. It's probably a little over the specs, but it works fine and A8Pico Atari users confirmed it works without level shifter since months. Of course the low quality of the ICs used in Pico clones and the overvoltage may lower the purple pico's life... but it costs only 3$, that's why i've a bunch of them in my store! ;) Anyway, since now i've reported no issue with Pico's GPIOs. |
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