BK-0010 Nostalgia page

This page is dedicated to two very popular Soviet home microcomputers of the 1980's and most of the 1990's: Elektronika BK-0010 and BK-0011M that had, unlike most home microcomputers in the USSR, not an 8-bit CPU, but a 16-bit CPU with the PDP LSI-11 instruction set. At the time of its debut it was several orders of magnitude cheaper than an IBM PC or its Western clone.

Here are the main features of BK-0010:

Production started in 1985, ended in 1993 or later
3 MHz clock, the manual claimed 300,000 op/sec; in reality a register-register operation required 12 clock cycles
16-bit QBUS provided on a 64-pin 2-row DIN connector
No peripherals in the configuration sold in stores; high schools were supplied with a current loop adapter (19200 baud) to connect to a classroom file server which usually was another Soviet PDP-11 clone - a DVK.
32 Kb RAM, out of which 16 Kb was either 512x256 black&white or 256x256 4-color hardware-scrollable framebuffer; the colors were Red, Green Blue, and Black
For details on CPU, see PDP-11s behind the Iron Curtain.
Software character generator in ROM
The ROM (almost 32 Kb) contained the BIOS (a keyboard driver, a screen driver, a tape recorder driver, an 8x10 font) and a language system; in the earlier model (BK-0010 proper) it was interpreted FOCAL, so there was enough ROM left to put some hardware tests; in the later model (Bk 0010.01) it was quite full-featured BASIC compiled into P-code; it occupied almost all address space, getting into the 0176xxx address range); this model was supplied with a cartridge containing the original (0010) ROM.
12 Kb of the framebuffer could be blanked out to increase the RAM available to the program to 28 Kb
A tape recorder was used for file storage, the encoding used was approx. 1200 bits/sec and not a very efficient or reliable one (pulse width modulation with a strobe after every bit)
No real-time clock interrupt, an undocumented programmable clock register was found by the enthusiasts by blind trial and error
A 16-bit universal parallel port provided on a 64-pin 2-row DIN connector with an IRQ line
There was a provision (two otherwise unused pins on the parallel port, on some production runs - two points on the motherboard) and some BIOS code) for a software-driven TTL-level serial connection with speeds up to 9600 baud. The baud rates were not particularly accurate (the claimed 9600 baud rate was not understood by other devices), but I worked with an U.S.-made modem on 4800 baud.

BK-0011 has clock speed of 4 MHz, had 128 Kb of RAM (still, the memory area above 0140000 was reserved for ROM), two frame buffer pages, switchable color palettes (out of 16 predefined sets of 4 colors), real-time clock interrupt, had ODT, better BASIC, and was able to run an RT-11 class OS. The early BK-0010 model had a few hardware bugs and was soon replaced with BK-0011M. A "HowTo" existed describing how to convert BK-0011 to BK-0011M by replacing a few chips.

Thanks to the available QBUS connector and a parallel port, a multitude of peripherals have been adapted or developed to be used with BK-0010 and BK-0011M: printers, mice, joystics, Covox, sound synthesizers, floppy and IDE controllers.

For a very long time it was believed that BK-0010, unlike most home microcomputers, had no Western counterpart or prototype. Lately I've learned that BK-0010 looks very much like a trimmed Terak 8510/a. I am adapting my BK-0010/11 emulator to emulate Terak as well, using whatever documentation is available on BitSavers. Boot ROM contents are needed to do it right.

A fairly new snapshot of the emulator is here. There is no Terak emulation yet, and it definitely is not a distribution. It uses SDL for graphics and native Linux audio for sound and synchronisation, therefore it only compiles and links under Linux. To compile, you will need the SDL development package.

If you have anything to send to me (clean Terak floppy images and Terak ROM images are particularly welcome), please write (do not forget to remove q's & x's). Thank you.

Useful links (in Russian only):

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