UKNC (Russian: УКНЦ) was a SovietPDP-11-compatible educational computer, aimed at teaching school informatics course. It is also known as Elektronika MS-0511. UKNC stands for Educational Computer by Scientific Centre.
Peripheral processor: KM1801VM2 @ 6 MHz (in newer models; or 4 MHz in early models, according to documentation)
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)
Keyboard: 88 keys
built-in LAN controller
built-in controller for special tape-recorder with computer control (to use for data storage, usually 5-inch FDD's were used)
An interesting part of the design is the usage of a peripheral processing unit (PPU). UKNC did not have full-featured controllers for display, LAN, keyboard, clock, in-hardware debugger etc. Instead, the PPU configured peripheral devices and managed their events. In other words, the PPU simulated all the controllers.
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 220V AC, while others utilized 41V DC. 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 case and keyboard (with changed markings) were re-used to produce an IBM PC clone, though less well-known than the once famous Poisk computer.
