Editing ES PEVM (section)

== Description ==
[[File:EC1834_k6313_1024px.jpg|thumb|EC-1834 with monitor K-7229.25 and printer K-6313]]
[[File:EC1835 C quer.jpg|thumb|ES-1835]]
[[File:EC1835 C IO Adapter.jpg|thumb|EC-1835 I/O adapter]]
[[File:Soviet made personal computer EC-1849 with Intel 80286 compatible CPU.JPG|thumb|ES-1849]]
The first models of ES PEVM (ES-1840, ES-1841, ES-1842), unlike the IBM PC, had two units: a system unit and a floppy drives unit. These models used a [[backplane]] instead of the main board. Although the system bus was compatible with [[Industry Standard Architecture|ISA]] bus, it used a different type of connector, so the IBM PC expansion cards could not be installed in ES PEVM.<ref name=mpss1>{{cite magazine
 | last = Кравчук
 | first = В.Г.
 | last2 = Некрасов
 | first2 = А.А.
 | last3 = Флорентьев
 | first3 = В.В.
 | title = Опыт работы с профессиональными персональными компьютерами ЕС1840
 | trans-title = Experience in the use of professional personal computers ES1840
 | language = Russian
 | magazine = Микропроцессорные средства и системы
 | issue = 4
 | year = 1989
 | page = 7
 | issn = 0233-4844
}}</ref>
Later models (ES-1843, ES-1849 etc.) were fully-compatible with IBM PC XT and IBM PC AT.

Unlike IBM PC using the [[Intel 8088]] processor, the early ES PEVM models used [[K1810VM86]] processor with a [[16-bit]] bus and a [[clock frequency]] of 5 MHz. The processor was placed on a separate board. Early versions of the board did not have a socket for the [[floating point]] [[coprocessor]].

The following boards were produced for ES-1840 and ES-1841:<ref>{{cite web
 | url = http://oldpc.su/pc/ec1840/ec1840.html
 | title = ПЭВМ ЕС-1840
 | language = Russian
}}</ref>
* [[CPU]] board (containing 54 chips). It was installed in every configuration of the computer.
* 128 [[KiB]] [[random-access memory|RAM]] board. It was installed in early models of ES PEVM.
* 512 KiB RAM board (containing 110 chips). Variants with 256 KiB or 128 Kib were available.
* [[IBM Monochrome Display Adapter|MDA]] adapter board (containing 91 chips). It was built using the [[Bulgaria]]n CM607 chip ([[MC6845]] clone).
* [[Color Graphics Adapter|CGA]] adapter board (containing 94 chips).
* [[Floppy drive]] adapter board (containing 32 chips). It was built using the Bulgarian CM609 chip (Intel 8272 clone).
* [[Serial interface]] adapter board (containing 56 chips). It was electrically incompatible with the IBM PC [[COM port]] and was not supported in the [[BIOS]].

Volume of production for a number of models:<ref>{{cite web
 | url = http://www.computer-museum.ru/histussr/es_pevm.htm
 | title = Персональные ЭВМ Единой системы и семейства ВМ
 | trans-title = Personal computers of the Unified System and VM family
 | author = Смирнов Г.Д.
 | language = Russian
}}</ref>
{| class="wikitable sortable"
|-
!| Model name
!| Year of production start
!| Year of production end
!| Volume of production (units)
|-
| ES-1831 || 1986 || || {{?}}
|-
| ES-1832 || 1986 || || {{?}}
|-
| ES-1834 || 1986 || 1989 || 13799
|-
| ES-1835 || 1989 || || {{?}}
|-
| ES-1838 || 1988 || || {{?}}
|-
| ES-1839 || 1987 || || {{?}}
|-
| ES-1840 || 1986 || 1989 || 7461
|-
| ES-1841 || 1987 || 1995 || 83937
|-
| ES-1842 || 1988 || 1996 || 10193
|-
| ES-1843 || 1990 || 1993 || 3012
|-
| ES-1845 || 1988 || || {{?}}
|-
| ES-1847 || 1988 || || {{?}}
|-
| ES-1849 || 1990 || 1997 || 4966
|-
| ES-1850 || 1989 || || {{?}}
|-
| ES-1851 || 1991 || 1997 || 3142
|-
| ES-1855 || 1991 || || {{?}}
|-
| ES-1861 || || || {{?}}
|-
| ES-1862 || || || {{?}}
|-
| ES-1863 || 1991 || 1997 || 3069
|-
| ES-1864 || 1991 || || {{?}}
|-
| ES-1865 || 1992 || || {{?}}
|}