Files
website/content/museum/pravetz-imko-1-2-pravetz-82.md
yann64andClaude Opus 5.5 b274874139 All machines linked to their forum thread (full comment import)
1,289 discussions, 9,527 archived comments; pages no longer carry the comments themselves.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YDRjtmAiNpo5mK5N3d7QwZ
2026-10-13 17:26:43 +02:00

6.7 KiB

title, categories, types, origins, years, cpus, params
title categories types origins years cpus params
Pravetz IMKO-1/2 & Pravetz 82
Computers
Home Computer
Bulgaria
1979
6502
name image company company_name specs tabs forum_thread photos adverts oc_id source
IMKO-1/2 & Pravetz 82 /media/museum/photos/pravetz_imko_system_2.jpg /companies/pravetz Pravetz
label value
NAME IMKO-1/2 & Pravetz 82
label value
MANUFACTURER Pravetz
label value
TYPE Home Computer
label value
ORIGIN Bulgaria
label value
YEAR 1979
label value
END OF PRODUCTION Unknown
label value
BUILT IN LANGUAGE Floating point BASIC interpreter. Several ROM expansion boards were available with Cobol, Fortran, Pascal, Logo, Ada languages
label value
KEYBOARD Full stroke 56 keys
label value
CPU 6502
label value
SPEED 1 MHz
label value
CO-PROCESSOR None
label value
RAM 48 KB expandable to 64 KB
label value
ROM 12 KB
label value
TEXT MODES 40 chars. x 24 lines
label value
GRAPHIC MODES 280x192 dots x 6 colours (or 280 x 160 + 4 text lines) in HiRes\ 40 x 40 squares (+4 text lines) or 40 x 48 in 16-colour mode.
label value
COLORS 16
label value
SOUND built-in speaker
label value
SIZE / WEIGHT 39 (W) x 45 (D) x 12 (H) cm
label value
I/O PORTS floppy drive, tape recorder, 8 expansion slots
label value
BUILT IN MEDIA None
label value
OS Apple OS
label value
POWER SUPPLY Built-in power supply unit
label value
PERIPHERALS All Apple II extensions
label value
PRICE 4190 Levs - About $2600
photos
adverts
932
title subtitle text image
IMKO-1 /media/museum/photos/pravetz_imko_system_s3.jpg
title subtitle text image
RIGHT SIDE /media/museum/photos/pravetz_imko_rightside_s1.jpg
title subtitle text image
KEYBOARD CLOSE-UP The lower case letters are replaced with the Cyrillic alphabet. The AAT keys are like Shift keys but toggle between the two alphabets. The yellow AAT key is like a 'Shift Lock'. The associate led lights when the Cyrillic alphabet is selected. the 'MK' key is like the 'Control' key, and 'OCB' means 'Escape'. /media/museum/photos/pravetz_imko_keyboard_s1.jpg
title subtitle text image
REAR SIDE Left side: Composite video jack and tape recorder DIN plug. Right side: AC/DC power fuses and power switch. /media/museum/photos/pravetz_imko_rear_s1.jpg
title subtitle text image
OPENED CASE Like the genuine Apple II, a trap door allows the user to add, remove expansion cards. The expansion slots could receive any Apple or compatible cards. /media/museum/photos/pravetz_imko_openedcase_s1.jpg
title subtitle text image
INSIDE The main board was an almost pure copy of the Apple II card. The card was made in Bulgaria but all the integrated circuits came from Asia, USA or Western Europe. The power supply was strong but simplistic and of old design. /media/museum/photos/pravetz_imko_inside_s1.jpg
title subtitle text image
IN USE Here with a Zenith monochrome composite monitor. /media/museum/photos/pravetz_imko_running_s1.jpg
title subtitle text image
DISPLAY CLOSE-UP A small Basic program allows to see that the character generator ROM holds both Cyrillic and latin alphabets. /media/museum/photos/pravetz_imko_charactersdisplay_s1.jpg
title subtitle text image
ROBKO-1 The arm robot Robko-1 /media/museum/photos/pravetz_imko_robkorobot_1.jpg
title subtitle text image
ADVERT #1 The display says: "Personal computer Pravetz 82" Thanks to **Bojidar Stefanov** /media/museum/pubs/pravetz_imko_pub_s1.jpg
title subtitle text image
ADVERT #2 Pravetz Apple II compatible technology and price are compared with the IBM compatible Pravetz 8C. Thanks to **Bojidar Stefanov** for the English translation /media/museum/pubs/pravetz_imko_pubcompar_s1.jpg
956
url date
https://web.archive.org/web/20230128071023/http://www.old-computers.com/museum/computer.asp?c=956 2023-01-28

In 1979, the Bulgarian Techical Cybernetics Institute took up with the idea of creating a small microprocessor based system.

In 1980 the first three Bulgarian microcomputers were produced. Their creators called the machine IMKO-1 for Individualen Micro KOmputer. In 1981 a series of few tenths machines was released. First users were enthusiastic about the versality and ease of use of the IMKO. Furthermore, the price wasn't very high.
Mass production started in 1982. First models shipped with a standard TV set instead of a monitor.

The IMKO-1 was actually an almost 100% compatible Apple II system featuring same expansion slots. Sadly, neither expansion card nor floppy disk unit were available in Bulgaria. Some rare customers bought them from Western European countries or from Taiwan, others used a tape recorder.

The first international presentation of the IMKO-1 occured at Robotics Symposium in England. Bulgaria demonstrated then a robot controlled by a microcomputer. At this time, Japaneses and U.S. robots were controlled by minicomputers. The IMKO-1 robot system cost thus ten times cheaper and its maintenance was much more easy.


Bozhidar Stefanov from Bulgaria adds:
Imko-1 and Imko-2 (almost the same machine with little upgrades) have been first manufactured in Sofia until 1982. The name was changed to Pravetz 82 when the computer was made in Pravetz, a small town near Sofia. It had a lot of peripherals like daisy whell printer, plotters or modems as well as loads of strange expansion boards specially manufactured for various factories. The Robot was called Robko 1 (an arm type robot)

Ivaylo Uzunoff reports :
Usually there was a monitor the same color as the computer box sitting on top of the main unit. The monitor had a black background, the symbols displayed on the monitor were green. usually on the right hand side there were two floppy drives one on top of another. They were connected with a wide "ribbon" cable to the main computer. To load OS you need to insert the disk into the flopy, since the computer did not had a HDD. Then you can insert a disk with primitive software or game.

We need more info about this computer ! If you designed, used, or have more info about this system, please send us pictures or anything you might find useful.