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