UKNC
UKNC () was 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
CPU: KM1801VM2 @ 8 MHz, 16 bit data bus, 17 bit address bus
Peripheral processor: KM1801VM2 @ 6.25 MHz
CPU RAM: 64 KB
PPU RAM: 32 KB, ROM: 32 KB, video RAM: 96 KB (3 planes 32KB 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). PPU unloaded the CPU, taking responsibility for the management of peripheral devices (display, audio, and so on), but could run any user programs, as well as CPU.

The computer was released in 3 sub-models: 0511, 0511.1, 0511.2. The 0511.1 model, intended for home use, had a power supply for 220 V AC, while others used 42 V AC. The 0511.2 featured 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 was no active cooling, and at least the 0511.2 variant tended 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 were 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, was re-used to produce an IBM PC clone called Elektronika MS-1502, though it less well-known than the once famous Poisk computer. The same case and keyboard were later used to produce yet 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