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# Z80-MBC2 |
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The [Z80-MBC2][link] combines a Z80 and an ATMEGA32A to provide a CP/m capable |
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computing environment. It features a SD card bootloader which makes running |
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Collapse OS on it rather simple. |
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## Recipe |
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In this recipe, we're going to run Collapse OS on the Z80-MBC2, interfacing |
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through its serial port. We're going to use the MBC's API to implement BLK on |
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the SD card. (the BLK part isn't done yet. TODO) |
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### Gathering parts |
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* A Z80-MBC2 computer with its SD card module and a properly flashed "IOS" on |
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the ATMega32A. |
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* A FTDI-to-TTL cable to connect to the serial port. |
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### Building the binary |
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Running `make` will yield `os.bin` which is what we want. |
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### Running on the Z80-MBC2 |
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Mount the SD card on your modern computer and copy `os.bin` as `autoboot.bin`, |
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overwriting the binary that was previously there. |
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Put back the SD card in the Z80-MBC2 and power it up by connecting the FTDI |
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adapter to it (red: VCC, black: GND, green: TX, white: RX). |
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The FTDI adapter will show up as something like `ttyUSB0` (or `ttyU0` on |
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OpenBSD). Connect to it with `screen` or `cu` or whatever you like. Baud rate of |
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the Z80-MBC2 appears to be hardcoded to 115200. |
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Then, enable IOS program selection by holding RESET and USER at the same time, |
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wait 2 seconds, releasing RESET, wait 2 seconds, releasing USER. You should then |
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be given a 1-8 choice, with 4 being "Autoboot". Type 4. |
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You are now in Collapse OS. |
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[link]: https://hackaday.io/project/159973-z80-mbc2-a-4-ics-homebrew-z80-computer |