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Re: New 65C02 SBC Project
Posted: Sat Apr 19, 2025 9:21 am
by djsb
Can you share your kicad files? Just want to learn about how the chips are connected? Am I free to copy your design or get my own PCB made(for my own use only) if you're able/willing to share? Thanks.
Re: New 65C02 SBC Project
Posted: Sun May 18, 2025 2:17 pm
by twenglish1
I have extra PCBs if you are interested, and i can share the schematic, I have since made more revisions to the design and the PCBs, adding an extra column of buttons, and connecting the RS-232 hardware control lines, and adding jumpers to connect/disconnect the USB UART IC to allow the RS-232 port to be used without removing the MCP2221. Only issue is that the MAX-232 chip needs to be removed when transmitting data to USB UART and if the hardware flow control isn't used, unless this can be dealt with in software, doesn't look like it though, the MAX-232 pulls the CTSB pin HIGH which halts any transmissions from the 65C51 until CTSB goes LOW indicating clear to send. Not sure what the best solution would be here, two separate 65C51s, one for USB UART and one for RS-232 seems to be the correct solution as UART is supposed to be between two devices only, or maybe adding logic to be able to select between them in software. I primarily use the USB UART when i am experimenting as it is nice loading programs to ram and not having to remove the ROM every time i want to change something.
EDIT: Corrected typos