.. | ||
Makefile | ||
README.md | ||
xcomp.fs |
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.
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.
We also have to copy the blkfs over. This is done by using IOS' drive system.
Each DSxNyy.DSK
file on the card is a drive, each drive has 512 track of 32
sectors of 512 bytes, so one drive is plenty for our needs. Collapse OS
hardcodes drive 0.
Each drive is part of a set. IOS theoretically supports up to 10 sets, but the
binary shipped by default only accepts 4. You have to overwrite an existing set.
I used set 3. So, copy blkfs
to file DS3N00.DSK
. If you want, you can change
the name of the set by changing the contents of DS3NAM.DAT
.
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.
You begin by selecting the proper disk set, which is through choice 8, then you select the Autoboot binary through choice 4.
You are now in Collapse OS.