Open-source Z80 calculator ROM

Free85

Loading Free85 ROM

Free85 2.21 documentation

Learn the calculator

Read the professionally typeset editions online, or download the print-ready PDFs.
Start here

Getting Started Manual

PDF
Complete reference

The Free85 Guidebook

PDF
Put it to work

Explorations with Free85

PDF
Debug drawerRegisters, display, memory, keyboard

Registers

Disassembly

    Machine

    Keyboard

    Display

    Memory

    Free85 is an independent clean-room project. Texas Instruments and TI-85 are referenced only to describe calculator compatibility. This project is not affiliated with or endorsed by Texas Instruments.