The Dubna 48K is a Soviet

Soviet Union

The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 clone of the ZX Spectrum

ZX Spectrum

The ZX Spectrum is an 8-bit personal home computer released in the United Kingdom in 1982 by Sinclair Research Ltd...

 home computer

Home computer

Home computers were a class of microcomputers entering the market in 1977, and becoming increasingly common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a single nontechnical user...

. It was based on an analogue of the Zilog Z80

Zilog Z80

The Zilog Z80 is an 8-bit microprocessor designed by Zilog and sold from July 1976 onwards. It was widely used both in desktop and embedded computer designs as well as for military purposes...

 microprocessor

Microprocessor

A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...

. Its name comes from Dubna

Dubna

Dubna is a town in Moscow Oblast, Russia. It has a status of naukograd , being home to the Joint Institute for Nuclear Research, an international nuclear physics research centre and one of the largest scientific foundations in the country. It is also home to MKB Raduga, a defence aerospace company...

, a town near Moscow

Moscow

Moscow is the capital, the most populous city, and the most populous federal subject of Russia. The city is a major political, economic, cultural, scientific, religious, financial, educational, and transportation centre of Russia and the continent...

 where it was produced, and "48K" stands for 48 KB

Kilobyte

The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information...

s of RAM

Ram

-Animals:*Ram, an uncastrated male sheep*Ram cichlid, a species of freshwater fish endemic to Colombia and Venezuela-Military:*Battering ram*Ramming, a military tactic in which one vehicle runs into another...

.

According to the manual, this computer was intended for:

• studying the principles of PC operation
• various kinds of calculations
• "intellectual games"

By the time this computer was released (1991), there were already much more powerful x86 CPUs and commercially available advanced operating systems, such as Unix

Unix

Unix is a multitasking, multi-user computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs, including Ken Thompson, Dennis Ritchie, Brian Kernighan, Douglas McIlroy, and Joe Ossanna...

, DOS

DOS

DOS, short for "Disk Operating System", is an acronym for several closely related operating systems that dominated the IBM PC compatible market between 1981 and 1995, or until about 2000 if one includes the partially DOS-based Microsoft Windows versions 95, 98, and Millennium Edition.Related...

 and Windows

Microsoft Windows

Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...

. The Dubna 48K had only a built-in BASIC

BASIC

BASIC is a family of general-purpose, high-level programming languages whose design philosophy emphasizes ease of use - the name is an acronym from Beginner's All-purpose Symbolic Instruction Code....

 interpreter

Interpreter (computing)

In computer science, an interpreter normally means a computer program that executes, i.e. performs, instructions written in a programming language...

, and loaded its programs from a cassette recorder, so evidently, it couldn't run any of modern operating systems, and as such, wasn't suitable for "studying the principles of PC operation". However, the Dubna 48K and many other Z80 clones, hopelessly outdated by that time, were largely introduced in high schools of the Soviet Union. According to a contemporary who studied at a school in Chelyabinsk

Chelyabinsk

Chelyabinsk is a city and the administrative center of Chelyabinsk Oblast, Russia, located in the northwestern side of the oblast, south of Yekaterinburg, just to the east of the Ural Mountains, on the Miass River. Population: -History:...

 in the 1980s, they used wooden plates with keyboard drawn on them, as the schools greatly lacked PCs for computer science lessons. So even these outdated computers were considered as a great boon.

Moreover, most of the games for the Z80 were already available for Nintendo's 8-bit game console, marketed in Russia under the brand Dendy, and it was a much cheaper, more reliable and easier way of playing games, so it became clear that the Dubna 48K wasn't in much demand for home users.

Included items

The Dubna 48K was shipped with the following units:

• Main unit ("data processing unit", as stated on its back side), with mainboard and built-in keyboard
• External power unit
• Video adapter for connecting the computer to the TV set
• BASIC programming manual
• Reference book, including complete schematic circuit

Additionally, there were some optional items:

• Joystick
• 32 cm (12") colour monitor

The computer could also connect to a ZX Microdrive

ZX Microdrive

The ZX Microdrive is a magnetic tape data storage system launched in July 1983 by Sinclair Research for their ZX Spectrum home computer. The Microdrive technology was later also used in the Sinclair QL and ICL One Per Desk personal computers.-Development:...

, but such device was never included.

Technical Details

• CPU
  Central processing unit
  The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...
  
  : 1.875 MHz, 8-bit
• RAM
  Ram
  -Animals:*Ram, an uncastrated male sheep*Ram cichlid, a species of freshwater fish endemic to Colombia and Venezuela-Military:*Battering ram*Ramming, a military tactic in which one vehicle runs into another...
  
  : 48 KB (in 16 KR565-series chips, see picture 4)
• ROM
  Read-only memory
  Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
  
  : 16 KB (picture 3, two white chips in the middle)
• Resolution: 256×192 pixels, or 24 rows of 32 characters each
• Number of colours: 8 colours in either normal or bright mode, which gives 15 shades (black is the same in both modes)
• RS-232
  RS-232
  In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DTE and a DCE . It is commonly used in computer serial ports...
  
  port
• Power unit: 5V, 1.7 A
• Dimensions of main unit: 52×320×255

See also