ES PEVM

<h2 id="description">Description</h2>

<p>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 <a href="/facts/Backplane/J6Hwe7Wl">backplane</a> instead of the main board. Although the system bus was compatible with <a href="/facts/Industry_Standard_Architecture/5Rk4bjqB">ISA</a> bus, it used a different type of connector, so the IBM PC expansion cards could not be installed in ES PEVM.<a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a>
Later models (ES-1843, ES-1849 etc.) were fully-compatible with IBM PC XT and IBM PC AT.
</p><p>Unlike IBM PC using the <a href="/facts/Intel_8088/DdWKfyBp">Intel 8088</a> processor, the early ES PEVM models used <a href="/facts/K1810VM86/6C9eNdt9">K1810VM86</a> processor with a <a href="/facts/16-bit/bTGS44Ne">16-bit</a> bus and a <a href="/facts/Clock_frequency/w055Woaj">clock frequency</a> of 5 MHz. The processor was placed on a separate board. Early versions of the board did not have a socket for the <a href="/facts/Floating_point/eIckahxe">floating point</a> <a href="/facts/Coprocessor/WsVXzAGo">coprocessor</a>.
</p><p>The following boards were produced for ES-1840 and ES-1841:<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a>
</p>
<ul><li><a href="/facts/CPU/Jxp1bqMV">CPU</a> board (containing 54 chips). It was installed in every configuration of the computer.</li>
<li>128 <a href="/facts/KiB/BNHUp9Qq">KiB</a> <a href="/facts/Random-access_memory/DuD4bxh6">RAM</a> board. It was installed in early models of ES PEVM.</li>
<li>512 KiB RAM board (containing 110 chips). Variants with 256 KiB or 128 Kib were available.</li>
<li><a href="/facts/IBM_Monochrome_Display_Adapter/oUM5MT24">MDA</a> adapter board (containing 91 chips). It was built using the <a href="/facts/Bulgaria/Er5pY3YS">Bulgarian</a> CM607 chip (<a href="/facts/MC6845/aSrFNs8T">MC6845</a> clone).</li>
<li><a href="/facts/Color_Graphics_Adapter/zcX23HQo">CGA</a> adapter board (containing 94 chips).</li>
<li><a href="/facts/Floppy_drive/rShxfuxa">Floppy drive</a> adapter board (containing 32 chips). It was built using the Bulgarian CM609 chip (Intel 8272 clone).</li>
<li><a href="/facts/Serial_interface/VpcrH530">Serial interface</a> adapter board (containing 56 chips). It was electrically incompatible with the IBM PC <a href="/facts/COM_port/0sMVyT0H">COM port</a> and was not supported in the <a href="/facts/BIOS/AYYPUogS">BIOS</a>.</li></ul>
<p>Volume of production for a number of models:<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a>
</p>
<table><tbody><tr><th>Model name</th><th>Year of production start</th><th>Year of production end</th><th>Volume of production (units)</th></tr><tr><td>ES-1831</td><td>1986</td><td></td><td><i>?</i></td></tr><tr><td>ES-1832</td><td>1986</td><td></td><td><i>?</i></td></tr><tr><td>ES-1834</td><td>1986</td><td>1989</td><td>13799</td></tr><tr><td>ES-1835</td><td>1989</td><td></td><td><i>?</i></td></tr><tr><td>ES-1838</td><td>1988</td><td></td><td><i>?</i></td></tr><tr><td>ES-1839</td><td>1987</td><td></td><td><i>?</i></td></tr><tr><td>ES-1840</td><td>1986</td><td>1989</td><td>7461</td></tr><tr><td>ES-1841</td><td>1987</td><td>1995</td><td>83937</td></tr><tr><td>ES-1842</td><td>1988</td><td>1996</td><td>10193</td></tr><tr><td>ES-1843</td><td>1990</td><td>1993</td><td>3012</td></tr><tr><td>ES-1845</td><td>1988</td><td></td><td><i>?</i></td></tr><tr><td>ES-1847</td><td>1988</td><td></td><td><i>?</i></td></tr><tr><td>ES-1849</td><td>1990</td><td>1997</td><td>4966</td></tr><tr><td>ES-1850</td><td>1989</td><td></td><td><i>?</i></td></tr><tr><td>ES-1851</td><td>1991</td><td>1997</td><td>3142</td></tr><tr><td>ES-1855</td><td>1991</td><td></td><td><i>?</i></td></tr><tr><td>ES-1861</td><td></td><td></td><td><i>?</i></td></tr><tr><td>ES-1862</td><td></td><td></td><td><i>?</i></td></tr><tr><td>ES-1863</td><td>1991</td><td>1997</td><td>3069</td></tr><tr><td>ES-1864</td><td>1991</td><td></td><td><i>?</i></td></tr><tr><td>ES-1865</td><td>1992</td><td></td><td><i>?</i></td></tr></tbody></table>
<h2 id="software">Software</h2>
<p>The computers were shipped with AlphaDOS, an entirely <a href="/facts/Russification/D9yUd7n9">Russified</a> version of <a href="/facts/MS-DOS/fVrrz1uN">MS-DOS</a>/<a href="/facts/PC_DOS/ScsfqAwQ">PC DOS</a> 2.x and 3.x. All <a href="/facts/Command_(computing)/zUrvQbFy">commands</a> were entered in Russian, for example, СМЕНКАТ for <a href="/facts/CHDIR/GRT0BkeF">CHDIR</a>. Files and <a href="/facts/File_extension/cJgfAym4">file extensions</a> were also in Russian, such as АТРИБ.ИСП for <a href="/facts/ATTRIB/t81evL39">ATTRIB.EXE</a>. The <a href="/facts/Operating_system/8XTuvMh2">operating system</a> used the <a href="/facts/Main_code_page_(Russian)/4eANv1WW">main code page</a>, hardwired into the display <a href="/facts/Read-only_memory/P9QMuDLH">ROM</a>; it was compatible neither with <a href="/facts/CP_866/EVzFRhhH">CP 866</a> nor CP 855, although partially with <a href="/facts/ISO%2fIEC_8859-5/RCKfCDGm">ISO/IEC 8859-5</a>.
</p>
<h2 id="reliability">Reliability</h2>
<p>Early models of ES PEVM were prone to failures due to manufacturing defects. The <a href="/facts/Mean_time_between_failures/lWCg38LX">mean time between failures</a> was around 350 hours.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a>
</p>
<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/History_of_computer_hardware_in_Eastern_Bloc_countries/038GVJ3U">History of computer hardware in Eastern Bloc countries</a></li>
<li><a href="/facts/ES_EVM/Y2xcSqWB">ES EVM</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>Кравчук, В.Г.; Некрасов, А.А.; Флорентьев, В.В. (1989). "Опыт работы с профессиональными персональными компьютерами ЕС1840" [Experience in the use of professional personal computers ES1840]. Микропроцессорные средства и системы (in Russian). No. 4. p. 7. ISSN 0233-4844. <a href="/wiki/ISSN_(identifier)" target="_blank">/wiki/ISSN_(identifier)</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>"ПЭВМ ЕС-1840" (in Russian). <a href="http://oldpc.su/pc/ec1840/ec1840.html" target="_blank">http://oldpc.su/pc/ec1840/ec1840.html</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>Смирнов Г.Д. "Персональные ЭВМ Единой системы и семейства ВМ" [Personal computers of the Unified System and VM family] (in Russian). <a href="http://www.computer-museum.ru/histussr/es_pevm.htm" target="_blank">http://www.computer-museum.ru/histussr/es_pevm.htm</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>Кравчук, В.Г.; Некрасов, А.А.; Флорентьев, В.В. (1989). "Опыт работы с профессиональными персональными компьютерами ЕС1840" [Experience in the use of professional personal computers ES1840]. Микропроцессорные средства и системы (in Russian). No. 4. p. 7. ISSN 0233-4844. <a href="/wiki/ISSN_(identifier)" target="_blank">/wiki/ISSN_(identifier)</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
</ol>

ES PEVM open-in-new

ES PEVM