Question: Which of these was produced by VEB, Robotron Z1013 or Gradiente Expert?

Context articles: VEB Robotron
KC 85
Robotron K 1840
Robotron Z1013
Robotron KC 87
A 5120
Gradiente Expert
Robotron K 1820
Combine (enterprise)
PC 1715

VEB Kombinat Robotron was the biggest East German electronics manufacturer.
 It was based in Dresden and employed 68,000 people (1989).
 It produced personal computers, SM EVM minicomputers, the ESER mainframe computers, several computer peripherals as well as home computers, radios and television sets.
The KC 85 ('KC' meaning "Kleincomputer", or "small computer") were models of microcomputers built in East Germany, first in 1984 by Robotron (the KC 85/1) and later by VEB Mikroelektronik "Wilhelm Pieck" Mühlhausen (KC 85/2, KC 85/3 and KC 85/4).
The K 1840 was a minicomputer from the German Democratic Republic (GDR).
 Its full name is "RVS K 1840" (RVS stands for "Rechnersystem mit virtuellem Speicher" – "computer system with virtual memory").
 Its development began in August 1985 at VEB Robotron Elektronik in Dresden, and it went into production in 1988.
The MRB Z1013 (Mikrorechnerbausatz = mikrocomputer kit) was an East German Single-board computer produced by VEB Robotron Riesa which was primarily intended for private use and educational institutions.
 It was powered by a U880 processor (a Z80 clone) and sold together with a membrane (flat foil) keyboard.
 Initially, the kit was equipped with 16-KByte DRAM, which was later replaced by a 64-KByte version.
The Robotron KC 87, fully known as the Kleincomputer robotron KC 87 ("KC" standing for "Kleincomputer", lit.
 "small computer"), was an 8-bit home computer released in 1987 and produced in East Germany by the VEB Robotron-Meßelektronik "Otto Schön" Dresden, part of the Kombinat Robotron.
 The first model in the series, the Robotron Z 9001, was introduced in 1984 and renamed Robotron KC 85/1 in 1985.
 Despite similar names, the Robotron home computers were not directly related to the KC 85 series produced by the VEB Mikroelektronik "Wilhelm Pieck" Mühlhausen.
The A 5120 was an office computer produced by VEB Robotron in Karl-Marx-Stadt (now Chemnitz), East Germany starting in 1982.
 The system featured an 8-bit microprocessor, the U880, a clone of the Zilog Z80.
 It was built for office work and had minimal graphics and sound capabilities.
 The price was between 27,000 and 40,000 East German marks (around 24,000-35,000 2016 US dollars) depending on equipment.
The Expert, made by Gradiente Eletrônica (to date best known as a game console and Hi-Fi equipment company) was the second and last MSX home computer launched in the Brazilian market, in the mid-1980s.
The K 1820 was a workstation developed in East Germany.
 Its more exact name was "RVS (computer system with virtual memory) K 1820" and its cipher in the SM EVM of the former COMECON countries was "SM 1720".
 VEB Robotron Elektronik Dresden began development of the K 1820 in 1986 and it went into serial production in 1990.
Combine (Russian: Комбинат ) is a term for industrial business groups or conglomerates in the socialist countries and particularly the former Soviet Union.
 Examples include VEB Kombinat Robotron, an electronics manufacturer, and IFA, a manufacturer of vehicles, both in East Germany, and the Erdenet copper combine in Mongolia.
The PC 1715 was an office computer produced by VEB Robotron in East Germany starting in 1985.
 The system featured an 8-bit microprocessor, the U880, a clone of the Zilog Z80.
 It was built for office work and had minimal graphics and sound capabilities.
 The price was 19,000 East German marks.