Elektronika BK 0010-01
======================

I have  several these  computers: they  are traditional  home computers
from 1980s (computers with integrated keyboards, with several ports and
which can  be connected to  old TVs) except  for two things:  they were
made in the USSR  and they do not have 8bit CPUs -  they run Soviet CPU
which is compatible with the PDP-11 (they are not copies so differences
in instruction set can be found).

These devices may be not so  impressive today: an PDP-11 CPU running at
3MHz,  16kB  of  RAM,  a  serial and  an  parallel  port  (mechanically
incompatible with usual  ones), tape device connector (a big  DIN one -
but any tape player will be OK here) and build-in BASIC (it seems to be
a simplified  MSX BASIC  clone and  not a DEC  BASIC as  it was  in the
Elektronika MK-90  portable computer). Graphics output  is limited (the
color output has 4  colors only - it was improved  in later models) and
there is  no acceleration. People  say that  CPU is powerful  enough to
overcome this limitation... By the  way, there is a DEC-compatible QBUS
(with mechanically different  connectors, of course) so  it is possible
to  connect other  peripherals -  HDDs  and floppies  are possible  but
another interface board is needed (of  course it is rare there days). I
read elsewhere that  some of original DEC accessories  can be connected
and used with some effort, too.

I have had issues  with TV output - first I  bought an old Czechoslovak
CRT  which  was designed  to  be  used as  an  output  device for  home
computers. I was able to catch very low quality signal (it was possible
to guess what is  on the screen but the most of  texts was not actually
readable).  Then I  have tried  an LCD  TV from  1990s -  there was  no
picture  at  all. I  suspected  the  old soviet  cables  but  I had  no
possibility to repair them correctly.

Recently  I have  found on  the  eBay a  seller who  have been  selling
DIN-SCART cables designed especially for these computers. The cable has
2 DIN connectors: one for B/W TV output and one for color TV output. So
I connected just  one first. No success  for any of the  cables. Then I
connected both  of them  - and  I have got  an excellent,  sharp, color
picture! At  the moment it  is just orange  on black but  the Wikipedia
says that it is the correct color mode  and I should be able to use ALL
FOUR COLOURS which this device offers!

Well, now I have to find a way  to pump data into device and out of it.
I  have  the DIN-3.5mm  adapter  so  it would  be  possible  to use  my
computer to  emulate a tape device  (any software tips?) I  also have a
Czechoslovak TESLA "walkman" which was  designed (among other tasks) to
be used  as data  storage device  for computers. But  I don't  have the
necessary cable (it was the big DIN connector for computer connection).


For now, I decided to try  an emulator. Surprisingly, there are many. I
downloaded one for the PPC Macs and  sources for the Linux one (it uses
the SDL 1.x - it was update in  2005 for the last time) [1]. I tried to
compile it and with minor alteration  of the Makefile (I had to replace
the "/usr/lib/libSDL.so"  with just "-lSDL") it  was actually compiled.
And it runs (I wrote a  very short BASIC program which worked correctly
- I did no more tests so far). If you think that it is not unusual then
please  note taht  it's  a C++  program  from early  2000s  and I  have
compiled it on a POWER9 (ppc64le) platform and not on a 32bit Intel one
for which it was originally written. So the authors of this program did
excellent work.

By the way,  a programming manual for this computer  is here [2]. There
are some strange Javascript scripts on  this page but the Links ("links
-g") handles this page very well. The manual is obviously in Russian.


References:

[1] https://sourceforge.net/projects/bk-terak-emu/
[2] http://simulators.narod.ru/bookbk.htm