title: UKNC
text: UKNC () is a Soviet PDP-11-compatible educational micro computer, aimed at teaching school informatics courses. It is also known as Elektronika MS-0511. UKNC stands for Educational Computer by Scientific Centre.
  
  Hardware
  Processor: KM1801VM2 1801 series CPU @ 8 MHz, 16 bit data bus, 17 bit address bus
  Peripheral processor: KM1801VM2 @ 6.25 MHz
  CPU RAM: 64 KiB
  PPU RAM: 32 KiB
  ROM: 32 KiB
  video RAM: 96 KiB (3 planes 32 KiB each, each 3-bit pixel had a bit in each plane)
  Graphics: max 640×288 with 8 colors in one line (16 or 53 colors on whole screen), it is possible to set an individual palette, resolution (80, 160, 320, or 640 dots per line) and memory address for each of 288 screen lines; no text mode.
  Keyboard: 88 keys (MS-7007), JCUKEN layout
  built-in LAN controller
  built-in controller for common or special tape-recorder with computer control (to use for data storage, usually 5-inch FDD's were used)
  
  One unique part of the design is the usage of a peripheral processing unit (PPU). Management of peripheral devices (display, audio, and so on) was offloaded to the PPU, which can also run user programs.
  
  The computer was released in 3 sub-models: 0511, 0511.1, 0511.2. The 0511.1 model, intended for home use, has a power supply for 220 V AC, while others use 42 V AC. The 0511.2 features new firmware with extended functionality and changed the marking of the keyboard's gray keys, compared to the initial version. The photo shows an 0511.2 variant.
  
  There is no active cooling, and at least the 0511.2 variant tends to overheat and halt after several hours of operation.
  
  The design of the case, the layout of the keyboard, the location and the shape of expansion slots are inspired by the Yamaha MSX system, which was purchased by the Soviet Union in the early 1980s for use in schools. The same case, with changed markings, is found with the IBM PC clone called Elektronika MS-1502. The same case and keyboard are found on another educational computer called Rusich (i8085 based).
  
  Software
  
  Operating system: RAFOS, FODOS (RT-11 clones), or RT-11SJ/FB
  LAN control program
  Programming languages:
  BASIC (Vilnius BASIC)
  Fortran
  Pascal
  Modula-2
  C
  Assembler
  Rapira
  E-practicum
  Logo
  Prolog
  Forth
  FOCAL
  
  See also
  DVK
  Elektronika BK-0010
  SM EVM
  
  External links
  
  UKNC emulator project; contains RT-11 images
  Archive software and documentation for Soviet computers UK-NC, DVK, and BK0010.
  
  Microcomputers
  Ministry of the Electronics Industry (Soviet Union) computers
  PDP-11