uplm80 0.2.0

Highly optimizing PL/M-80 compiler targeting 8080/Z80

uplm80 - PL/M-80 Compiler

A modern PL/M-80 compiler targeting Intel 8080 and Zilog Z80 assembly language.

PL/M-80 was the primary systems programming language for CP/M and other 8080/Z80 operating systems. This compiler can rebuild original CP/M utilities from their PL/M source code.

Repository: https://github.com/avwohl/uplm80

Features

• Full PL/M-80 language support
• Targets both 8080 and Z80 instruction sets
• Multiple optimization passes (peephole, post-assembly tail merging)
• Generates relocatable object files compatible with standard CP/M linkers
• Produces code competitive with the original Digital Research compiler

Code Quality

Compiled output is comparable to the original Digital Research PL/M-80 compiler:

Program	DR PL/M-80	uplm80	Difference
PIP.COM	7424 bytes	7127 bytes	-4.0%

Installation

Install from PyPI:

pip install uplm80

Or install from source:

git clone https://github.com/avwohl/uplm80.git
cd uplm80
pip install -e .

Usage

Compile PL/M-80 to Assembly

uplm80 input.plm -o output.mac

Or run as a module:

python -m uplm80.compiler input.plm -o output.mac

Options:

• -t 8080 or -t z80 - Target CPU (default: Z80)
• -o output.mac - Output file name

Post-Assembly Optimization (Optional)

python -m uplm80.postopt output.mac -o output_opt.mac

Performs multi-pass tail merging and skip trick optimizations.

Assemble and Link

Use your preferred 8080/Z80 assembler and linker. Example with um80/ul80:

um80 output.mac                              # Assemble to .rel
ul80 -o program.com output.rel runtime.rel   # Link to CP/M .com

Language Reference

PL/M-80 is a typed systems programming language with:

• Data types: BYTE (8-bit), ADDRESS (16-bit)
• Variables: Scalars, arrays, structures, BASED variables (pointers)
• Control flow: DO/END, DO WHILE, DO CASE, IF/THEN/ELSE
• Procedures: With parameters, local variables, recursion
• Built-in functions: HIGH, LOW, DOUBLE, SHL, SHR, ROL, ROR, etc.
• I/O: INPUT, OUTPUT for port access

Example:

hello: DO;
    DECLARE message DATA ('Hello, World!$');
    DECLARE i BYTE;

    print: PROCEDURE(addr) PUBLIC;
        DECLARE addr ADDRESS;
        /* CP/M BDOS print string */
        CALL mon1(9, addr);
    END print;

    CALL print(.message);
END hello;

Runtime Library

The compiler generates calls to these runtime routines (provide in a separate .rel file):

Routine	Description
??MUL	16-bit unsigned multiply
??DIV	16-bit unsigned divide
??MOD	16-bit unsigned modulo
??SHL	16-bit shift left
??SHR	16-bit logical shift right
??SHRS	16-bit arithmetic shift right
??MOVE	Block memory move

CP/M Programs

For CP/M programs, provide stubs for:

• MON1, MON2, MON3 - BDOS calls
• BOOT - Warm boot
• BDISK, MAXB, FCB, BUFF, IOBYTE - System variables

Project Structure

uplm80/
├── compiler.py    # Main compiler driver
├── lexer.py       # Tokenizer
├── parser.py      # PL/M-80 parser
├── ast_nodes.py   # AST definitions
├── codegen.py     # Code generator
├── peephole.py    # Peephole optimizer
├── postopt.py     # Post-assembly optimizer
└── symbols.py     # Symbol table

License

This project is licensed under the GNU General Public License v3.0 or later - see the LICENSE file for details.

Contributing

Contributions are welcome! Please feel free to submit issues and pull requests.

Acknowledgments

• Digital Research for creating PL/M-80 and CP/M
• The CP/M source code preservation efforts that made the original PL/M sources available