cpm80

CP/M-80 2.2 emulator with Python API.

Based on the fast and flexible z80 emulator.

Running the 1982 CP/M game Ladder, loaded straight from the host directory:

Installing

$ pip install cpm80

Running and terminating

$ cpm80
62k CP/M vers 2.2

A>save 1 dump.dat
A>dir
A: DUMP     DAT
A>exit

Enter exit or just hit Ctrl + C three times to quit the emulator.

Exchanging files with the host

--mount <dir> puts a host directory on the next drive, and fresh disks come with PIP, so files just copy.

$ ls
hello.txt
$ cpm80 --mount .
62k CP/M vers 2.2

A>dir b:
B: HELLO    TXT
A>pip a:=b:hello.txt
A>save 1 b:dump.dat
A>exit
$ ls
DUMP.DAT  hello.txt

--mount also takes a disk image file instead of a directory. A single Ctrl + C re-reads a mounted directory -- the usual CP/M way of telling the system the disk has changed.

Running commands automatically

From the command line:

$ cpm80 dir 'save 1 a.dat' dir

Alternatively, we can use the API's StringKeyboard class to feed arbitrary commands to the command processor, CCP, thus replacing KeyboardDevice console readers used by default:

import cpm80

COMMANDS = (
    'dir',
    'save 1 a.dat',
    'dir',
    )

console_reader = cpm80.StringKeyboard(*COMMANDS)
m = cpm80.I8080CPMMachine(console_reader=console_reader)
m.run()

string_keyboard.py

Output:

62k CP/M vers 2.2

A>dir
NO FILE
A>save 1 a.dat
A>dir
A: A        DAT
A>

Getting output as a string

Similarly, we can replace DisplayDevice console writers used by default with custom writers to do special work for the emulator's output. For example, one could use a StringDisplay writer to gather the output into a string.

d = cpm80.StringDisplay()

m = cpm80.I8080CPMMachine(
    console_reader=cpm80.StringKeyboard('dir'),
    console_writer=d)

m.run()

print(d.string)

string_display.py

Making BDOS calls

BDOS calls can be performed on the machine object directly or by using convenience wrappers.

m = cpm80.I8080CPMMachine()

STR_ADDR = 0x100
m.set_memory_block(STR_ADDR, b'Hello $')
m.bdos_call(m.C_WRITESTR, de=STR_ADDR)

m.write_str('World!\n')

bdos_call.py

Working with files

Similarly, using BDOS wrappers one can manipulate files on disks.

drive = cpm80.DiskDrive()

m = cpm80.I8080CPMMachine(drives=[drive])
m.make_file('file.txt')
m.write_file(f'bin(100) is {bin(100)}\n'.encode())
m.close_file()
del m

# Then read and print the contents of the file using another machine.
m = cpm80.I8080CPMMachine(drives=[drive])
m.open_file('file.txt')
print(m.read_file())
m.close_file()

doing_files.py