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Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallCRISS is a DIY single-board computer that runs CP/M 2.2 software by emulating a Z80 processor on an AVR microcontroller. It pairs that classic software environment with practical modern connections, including VGA video, an SD card for disk images and a standard PS/2 keyboard.
What is CRISS CP/M?
CRISS is a 21st-century, AVR-based single-board computer designed to run CP/M, the operating system used on many early personal computers. Its 20 MHz ATmega1284P emulates a 4 MHz Z80 processor; ATmega328 microcontrollers handle peripheral control and VGA output. The project describes the system and its specifications on the official CRISS project site.
Rather than requiring a vintage computer, CRISS recreates a CP/M-era software environment on a compact board. Its stated enclosure dimensions are approximately 140 × 110 × 35 mm, and the PCB measures 100 × 130 mm.
How does CRISS run CP/M on modern hardware?
The ATmega1284P executes Z80 instructions through machine-code emulation, allowing CRISS to run CP/M programs without using a Z80 chip. The official project specifies 64 KB of SRAM, with about 55 KB available as the transient program area (TPA), where CP/M programs can run. The 55 KB figure is documented in the Hackaday.io project description.
#1 Best Overall
CP/M applications and floppy-disk images are stored on an SD card. This replaces the need to locate and maintain period floppy disks and drives, while preserving the disk-image workflow familiar to CP/M users. The CRISS project is also described in a 2021 Hackaday overview, which reported demonstrations of programs including Turbo Pascal, Xonix and Tetris. Those examples are historical demonstrations, not a guarantee that every program or version will work.
What hardware and connections does CRISS support?
The project documents interfaces intended to connect the CP/M environment to contemporary peripherals and storage. Exact capabilities may vary with firmware revision.
Rank #2
- THREE PRESOLDERED USB-C BOARDS FOR MORE PROJECTS - Keep one Nano on a breadboard, embed another in a robot or sensor node and reserve the third for testing; one USB-A to USB-C data cable is included for programming, while jumper wires, sensors and breadboards are sold separately
- ATMEGA328P PERFORMANCE IN A COMPACT FORMAT - Run familiar 5 V, 16 MHz AVR sketches with 32 KB flash, 2 KB SRAM and 1 KB EEPROM, plus 14 digital I/O pins, 6 PWM outputs and 8 analog inputs for LEDs, buttons, displays, sensors, motor drivers and data logging
- CH340 USB SETUP WITH PRACTICAL UPLOAD GUIDANCE - Install the CH340 driver if no serial port appears, select Nano and the correct COM port, then upload a Blink test; use the included USB-A to USB-C cable because the current board does not support USB-C to USB-C host cables
- PRESOLDERED HEADERS SAVE BREADBOARD SPACE - The 18 × 45 mm footprint arrives ready to plug into a solderless breadboard, while UART, I2C and SPI support serial modules, displays, storage and sensors without soldering header pins before the first project
- POWER AND MODEL EXPECTATIONS - Use USB-C, 7-12 V VIN or a regulated 5 V input, share ground and drive motors or relays through suitable modules; this classic Nano V3-style board has no Wi-Fi, Bluetooth or features from Nano Every, Nano 33, Nano ESP32 or Nano R4
| Connection or feature | What it is for |
|---|---|
| VGA | Connects to a monitor; monochrome and eight-color modes are listed by the official project. |
| SD card | Stores floppy-disk images used by the system. |
| PS/2 keyboard | Provides standard keyboard input. |
| Serial and RS-232/system UART | Supports serial communication and printer connections. |
| Ethernet | Adds a network interface; supported uses depend on software and firmware. |
| Real-time clock | Battery-backed clock for keeping time. |
| GPIO and I2C | Provides expansion and peripheral connections. |
| Optional LPT | Supports parallel-port printer use when the optional interface is fitted. |
| PS/2 mouse | Listed in the Hackaday.io project description; confirm support for the particular firmware in use. |
The Hackaday.io description also lists 128 KB of EPROM for three switchable user sessions and terminal emulation for VT100, Robotron PC1715, Kaypro II, ADM, Microbee and TRS-80 systems. These are project-documented features; the description does not establish that every option is present or enabled on every build.
Can CRISS run Kaypro or Robotron software?
Yes. The official project says CRISS can run programs written for Kaypro II and Robotron 1715 computers, and lists emulation modes for Robotron 1715 (Russian and European versions), Kaypro II/ADM and TRS-80. A program’s compatibility still depends on its hardware assumptions and the selected mode; the project descriptions do not promise compatibility with every program for those machines.
Rank #3
- Teensy 2.0 USB AVR: Using the Teensy 2.0 USB AVR chip, it has high performances processing capabilities and stable USB connection, reliably supporting various application scenarios.
- Powerful scalability: Supports rich interfaces and pins, making it convenient for users to expand and customize their functions according to their own needs.
- Easy to use: Provides a friendly development environment and a simple and easy to understand programming language, allowing users to quickly and implement various functions.
- Strong compatibility: It has good compatibility with mainstream operating and software, and can be developed on multiple platforms such as
- Multi functional development board: This product is a multifunctional development board that supports various experimental applications such as keyboard, ISP, and USB meeting different development and testing needs.
This compatibility reflects a key advantage of CP/M: software could be used across different Z80-based computers when their system and hardware interfaces were compatible. CRISS extends that idea by offering configurable platform and terminal emulation rather than requiring the original machine. The 2021 Hackaday coverage provides historical context and demonstrations, not an exhaustive compatibility list.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.What do you need to use CRISS?
For a basic setup, plan on a CRISS board, a VGA monitor, a PS/2 keyboard and an SD card containing the disk images and software you intend to use. The project also lists serial connections and optional printer and expansion interfaces. Ethernet is available as a documented interface, but the project information cited here does not specify a particular network service or configuration procedure.
Rank #4
- 2.4GHz Dual Mode WiFi + Bluetooth Development Board
- Support LWIP protocol, Freertos;ESP32 is a safe, reliable, and scalable to a variety of applications
- SupportThree Modes: AP, STA, and AP+STA
- Ultra-Low power consumption, Compatible with Arduino IDE
- 1PCS 30Pin ESP32 Development Board 2.4GHz WiFi Dual Cores Microcontroller Integrated with Antenna RF Low Noise Amplifiers Filters
- Display: a VGA monitor, with monochrome or eight-color output available according to the official specification.
- Input: a standard PS/2 keyboard.
- Storage: an SD card for floppy images.
- Optional peripherals: serial printer, optional LPT printer, network connection or GPIO/I2C expansion, depending on the intended use and build.
What to know before choosing CRISS
CRISS is a DIY project, not a conventional turnkey computer listing. The project pages document its design and capabilities, but do not establish a current retail price, production run, warranty or independent benchmark results. If you are evaluating a build, check the current project documentation and firmware-specific details for the interfaces and emulation modes you need.
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