Jump to content


From Wikipedia, the free encyclopedia
An early U880D microprocessor, manufactured in December 1981
General information
Discontinuedc. 1996
Common manufacturer
  • VEB Mikroelektronik "Karl Marx" Erfurt
Max. CPU clock rate1 MHz to 8 MHz
Architecture and classification
Instruction setZilog Z80
Physical specifications

The U880 is an 8-bit microprocessor that was manufactured by VEB Mikroelektronik "Karl Marx" Erfurt (abbreviated as MME; part of Kombinat Mikroelektronik Erfurt) in the German Democratic Republic. Production of the U880 started in 1980[1] at VEB Funkwerk Erfurt (abbreviated as FWE; the plant was renamed to VEB Mikroelektronik "Karl Marx" in 1983[2]). The U880 is an unlicensed clone of the Zilog Z80 microprocessor, also supporting illegal opcodes and bugs, except for very minor differences like not setting the CY flag for the OUTI command (when L goes zero).

Processor variants[edit]

Die of the U880; size 4513 μm x 4251 μm (first die shrink 1984); chip inscription at the bottom of the image: "U880/5 HL JH 84"
Die of the U880; size 3601 μm x 3409 μm (second die shrink 1990); chip inscription at the bottom of the image: "U880/6 HL MME 1990"

The U880 was manufactured in NMOS technology and encased in a plastic DIL40 package with a pin spacing of 2.5 mm[3][4] (export versions had the Western pin spacing of 2.54 mm; Russian variants also came in a ceramic package).

Temperature range Clock rate Designations
0 °C to 40 °C 1 MHz UD880D,[a][5] UB880D S1[a][6]
0 °C to 70 °C 2.5 MHz U880D,[b][3] UB880D,[4] 80-CPU[c]
4 MHz UA880D,[4] 80A-CPU[c]
8 MHz U880DC08,[d] Thesys Z80H[e]
−25 °C to +85 °C 2.5 MHz VB880D[4]
  1. ^ a b Out-of-spec, hobbyist version
  2. ^ Original designation when this was the only variant available
  3. ^ a b Designation for export; 2.54 mm pin spacing
  4. ^ Manufactured in 1992 by ERMIC
  5. ^ Manufactured after 1992 by Thesys

The military version of the U880 has an additional "MEK 4" marking.

Support chips[edit]

Floppy-disk controller U8272D04 (1989)
Graphics display controller U82720DC03 (1989)

VEB Mikroelektronik "Karl Marx" also manufactured a number of support chips for the U880. The prefixes UA, UB, VB, 80, and 80A correspond to the same temperature ranges and clock rates as for the processor variants above. Likewise, the suffix S1 indicates the out-of-spec, hobbyist version.

Designation International equivalent Description
U855D,[a][3] UA855D,[4][7] UB855D,[4][7] UD855D,[b][5] VB855D,[4] UB855D S1,[b][6] 80-PIO,[c] 80A-PIO[c] Zilog Z80 PIO parallel input/output
U8560D,[a][3] UA8560D,[4] UB8560D,[4][7] VB8560D,[4] UB8560D S1,[b][6] 80-SIO/0,[c] 80A-SIO/0[c] Zilog Z80 SIO/0 serial input/output
U857D,[a][3] UA857D,[4][7] UB857D,[4][7] VB857D,[4] UB857D S1,[b][6] 80-CTC,[c] 80A-CTC[c] Zilog Z80 CTC counter/timer circuit
UA858D,[4] UB858D,[4] UB858D S1,[b] 80-DMA,[c][7] 80A-DMA[c] Zilog Z80 DMA DMA controller
U8561D,[a] UB8561D[8] Zilog Z80 SIO/1 serial input/output
UA8563D,[4] UB8563D,[4] VB8563D,[4] UB8563D S1,[b] 80-DART,[c] 80A-DART[c] Zilog Z80 DART dual asynchronous receiver/transmitter
U8272D04,[4] U8272D08[4] Intel 8272 floppy-disk controller
U82530DC04,[9] U82530DC06[9] Zilog SCC serial communications controller
U82536DC04[9] Zilog CIO counter/timer and parallel input/output
U82720DC02, U82720DC03, U82720DC04[4] Intel 82720 graphics display controller
  1. ^ a b c d Original designation when this was the only variant available
  2. ^ a b c d e f Out-of-spec, hobbyist version
  3. ^ a b c d e f g h i j Designation for export; 2.54 mm pin spacing


The U880 was by far the most widely used microprocessor in the German Democratic Republic. Examples are:

At the time the U880 was the most advanced 8-bit processor available in the Eastern Bloc. Only clones of the Intel 8080 were manufactured in Poland, Czechoslovakia, Hungary, Romania, and the Soviet Union. As the Z80 replaced the Intel 8080 in the West, the U880 was used throughout the Eastern Bloc. Examples are:

Further development[edit]

Microprocessor T34VM1 (Angstrem Zelenograd, 1991)

Following the example of Zilog where the Z80 was succeeded by the 16-bit processors Z8001 / Z8002, VEB Mikroelektronik "Karl Marx" produced the U8001 / U8002. And just like its Western counterpart, the U8001 / U8002 saw far less use than the U880. When MS-DOS emerged as the dominant operating system for personal computers, in the Eastern Bloc the only available clone of the Intel 8086 was the Soviet K1810VM86. VEB Mikroelektronik "Karl Marx" then proceeded to develop a clone of the Intel 80286, the U80601.[9] Furthermore, a CMOS version of the Z80 was developed with the designation U84C00.[9][15][16] Due to the economic changes following the German reunification in 1990, neither project proceeded beyond pilot production. VEB Mikroelektronik "Karl Marx" (MME) was privatized in 1990 under the name ERMIC GmbH, a large part of which became Thesys Gesellschaft für Mikroelektronik mbH in 1992.[17] Both ERMIC and Thesys continued to manufacture the NMOS version of the U880, ERMIC still with the MME name and logo,[18] Thesys under its new name. A die shrink chip with the marking U880/6 had been developed in 1990 and went into production some time after that. The smaller chip allowed clock rates up to 8 MHz for the U880DC08 and Thesys Z80H. While Zilog likely could have taken up legal action against the successors of VEB Mikroelektronik "Karl Marx" for copyright infringement, they recruited Thesys as a Zilog distributor instead.[19]

From about 1991 until 1993, bare U880 chips were sold to Russian and Ukrainian companies and packaged there. Initially the U880/5 chip revision was labelled as 80A-CPU[20] and T34VM1 [ru] (Russian: Т34ВМ1).[21] Later integrated circuits with U880/6 chips inside received the official designation KR1858VM1 [ru] (Russian: КР1858ВМ1) for the plastic package and KM1858VM1 (Russian: КМ1858ВМ1) for the ceramic package.[22] Manufacturers include Angstrem Zelenograd, Kvazar Kiev, and VZPP Voronesh.[22]


  1. ^ Berkner, Jörg (2016-04-12). "Die Halbleiterindustrie in der DDR" (in German). Hüthig GmbH. Retrieved 2017-11-07.
  2. ^ "Ehrennamen "Karl Marx" für Erfurter Betrieb". Neues Deutschland (in German). 1983-10-06. Retrieved 2017-11-03.
  3. ^ a b c d e RFT Semiconductors 1981 (PDF). elektronik export-import. 1981. pp. 20–21, 28–33. Retrieved 2018-01-16.
  4. ^ a b c d e f g h i j k l m n o p q r s t u RFT Aktive elektronische Bauelemente 1988 [RFT Active electronic components 1988] (PDF) (in German). VEB Kombinat Mikroelektronik. July 1987. pp. 243–258, 310–313, 326–328. Retrieved 2018-01-16.
  5. ^ a b "UD 880 und UD 855" [UD 880 and UD 855]. Radio Fernsehen Elektronik (in German). 35 (2). VEB Verlag Technik: 70. 1986. ISSN 0033-7900.
  6. ^ a b c d "Unipolare Amateur-IS (Übersicht)" [Unipolar hobbyist IC (overview)]. Funkamateur (in German). Militärverlag der DDR. January 1989. pp. 27–28. ISSN 0016-2833. Retrieved 2018-01-16.
  7. ^ a b c d e f "East German, and Soviet Support Chips". The CPU shack. 2005. Retrieved 2018-02-22.
  8. ^ Kramer, Manfred (1986-02-15). Praktische Mikrocomputertechnik [Practical microcomputer technology] (in German). Militärverlag der DDR. p. 214. ISBN 3-327-00361-0.
  9. ^ a b c d e Mikroelektronik Gesamtübersicht [Microelectronics - Complete overview] (PDF) (in German). Applikationszentrum Elektronik Berlin. 1990. Retrieved 2018-01-17.
  10. ^ "Tesla Ondra". HCM. Retrieved 2018-01-13.
  11. ^ "Microkey Primo A-32". Old-Computers.com. Retrieved 2018-03-27.
  12. ^ "Electro Magnetica: Jet". HCM. Retrieved 2018-01-13.
  13. ^ a b "SCIENCE & TECHNOLOGY - EUROPE & LATIN AMERICA" (PDF). Defense Technical Information Center. 22 June 1987. pp. 66–75. Archived from the original on August 25, 2016. Retrieved 12 February 2018.
  14. ^ Kasper, B.; Löschner, V. (1985). "Leipziger Frühjahrsmesse 1985" [Leipzig Spring Fair 1985]. Radio Fernsehen Elektronik (in German). 34 (6). Berlin: VEB Verlag Technik: 350. ISSN 0033-7900.
  15. ^ "U84C00". 2013-03-27. Retrieved 2018-01-17.
  16. ^ "MME U84C00". 2008-06-22. Retrieved 2018-01-17.
  17. ^ "Kombinat Mikroelektronik Erfurt" (in German). Archived from the original on 2007-09-27. Retrieved 2017-11-14.
  18. ^ "Funkwerk Erfurt (FWE) Z80/Z80A". Silirium.ru. Retrieved 2018-03-21.
  19. ^ "International Representatives and Distributors". Zilog, Inc. Archived from the original on 1996-12-12. Retrieved 2018-01-22.
  20. ^ "80A-CPU MME" (in Russian). Музей электронных раритетов. Retrieved 2019-10-29.
  21. ^ "Т34ВМ1" [T34VM1] (in Russian). Музей электронных раритетов. Retrieved 2019-10-29.
  22. ^ a b "1858ая серия" [1858 series] (in Russian). Музей электронных раритетов. Retrieved 2019-10-29.

Further reading[edit]

External links[edit]