CRISS CP/M

CRISS CP/M - Modern DIY CP/M Computer!

CRISS CP/M is a 21st-century CP/M single-board computer based mainly on AVR microcontrollers. The CPU is a 20 MHz ATMEGA1284P, which imitates a 4 MHz Z80 through machine-code emulation. A pair of ATMEGA328s run the peripheral controller and a VGA output, so the CRISS can be used with modern monitors. Standard image is monochrome green-on-black, looking instantly familiar to users of Kaypro's, Osborne's and other contemporary CP/M machines. But for new programs additional circuit based on the ATTINY84 MCU provides 8 basic colors!

Software is loaded through an SD card that holds floppy images. The CRISS can directly run programs written for the Kaypro II and Robotron 1715 computers, although other platforms can be supported as well with a software upgrade.

Housed in a neat little case (13x10cm PCB size), the CRISS can communicate with standard PS/2 keyboards and serial printers. Even an Ethernet port is provided for those willing to experiment with network connectivity (a rare feature in the 1980s).

Basic characteristics:

• CP/M operating system: many programming languages, games, text editors, spreadsheets, databases;
• Built-in BIOS support;
• Processor: Z80 (Zilog) in emulation mode, register-register command execution speed 1 μs;
• RAM: SRAM 64Kb, 55 Kb TPA!;
• Video adapter: VGA, 8 colors or monochrome, alphanumeric up to 25x80 or 31x64chars, 4 switchable character tables, graphics 160x96 pixels;
• Storage: SD-card, support for 819 KB floppy images, etc .;
• Keyboard: standard PS/2 keyboard, local and LAT layouts;
• Printer: standard with serial interface;
• Communication interfaces: RS-232, system UART;

Really cool? But it is not the end of the list, there are also available:

• 128 Kb EEPROM that allows to switch between 3 user sessions;
• Real time clock with the backup battery;
• Ethernet controller embedded into BIOS;
• Single-tone music generator with built-in amplifier and speaker;
• GPIO support - up to 128 digital I/O lines (external module);
• LPT-port support (external module).

CRISS CP/M has its own settings, but it can emulate other hardware platforms and terminals emulation, for now it supports Robotron 1715 (RU and EU versions), Kaypro II/ADM and TRS-80!

Power supply: AC 120-230 V 50-60 Hz. SIngle box 140x110x35 mm size, PCB size 100x130 mm.

And what absolutely unbelievable: only DIP components! Anyone can solder it, detailed video how to do it available!

CRISS CP/M - modern DIY(!!!) computer for entertainment and more! Don't forget to visit and like the project page at HACKDAY.IO!

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