kz80_db

A dBASE II clone for the Z80 RetroShield.

This project generates a Z80 ROM that implements a subset of dBASE II, the classic database management system from 1981. It runs on the RetroShield Z80 with SD card storage emulation.

Features

• Authentic dBASE II file format compatibility
• Interactive command-line interface
• SD card storage via I/O port emulation

Commands

Startup File

Like the original dBASE II, kz80_db supports automatic command execution at startup. If a file named STARTUP.CMD exists in the storage directory, its contents will be executed as commands when the program starts.

Example STARTUP.CMD:

USE MYDB
COUNT

This will automatically open the MYDB database and display the record count.

File Extensions

The .DBF extension is automatically appended to database filenames if no extension is provided, matching original dBASE II behavior:

• USE MYDB opens MYDB.DBF
• USE MYDB.DBF also opens MYDB.DBF

Building

cargo build --release
./target/release/kz80_db

This generates db.bin, a Z80 ROM image.

Running

Use with the RetroShield emulator:

../emulator/retroshield db.bin

Testing

cargo test

Runs both unit tests and integration tests (requires the emulator).

dBASE II File Format

The implementation uses the authentic dBASE II format:

Header (8 bytes):

• Byte 0: Version (0x02)
• Bytes 1-2: Record count (16-bit LE)
• Bytes 3-6: Last update date
• Byte 7: Record length

Field Descriptors (16 bytes each):

• Bytes 0-10: Field name
• Byte 11: Type (C=Character, N=Numeric)
• Byte 12: Field length
• Terminated by 0x0D

Records:

• First byte: Delete flag (space=active, *=deleted)
• Remaining bytes: Field data (space-padded)

License

BSD 3-Clause. See LICENSE.