Z80-MBC2: a 4 ICs homebrew Z80 computer
10 hours ago
- #Z80
- #RetroComputing
- #Arduino
- Hardware overview includes Z80 CPU CMOS, Atmega32A, TC551001-70 RAM, and 74HC00.
- Atmega32A serves as I/O subsystem, EEPROM, and clock generator for Z80 CPU.
- Arduino bootloader is flashed onto Atmega32A, followed by IOS sketch upload via Arduino IDE.
- ICSP port J3 is used for bootloader flashing; disconnect other connectors during use.
- 16MHz Atmega32A oscillator serves as clock source for Z80 CPU.
- 74HC00 acts as RS flip-flop to manage Z80 CPU during I/O operations.
- Only CMOS version of Z80 CPU is compatible due to logical level requirements.
- Components can be substituted with equivalents (e.g., 74HCT00 for 74HC00, other 128kB SRAM for TC551001-70).
- USER LED must be blue, white, or pink to ensure correct Vf (≥2.7V).
- GPE option adds 16 GPIO pins via MCP23017, usable with SPP Adapter board.
- Serial port (J2) supports TTL-RS232 or serial-USB adapters for power and data.
- For DOS (not Windows), a V40 CPU is suggested as a better alternative.