website/content/museum/r-f-t-kc-85-4.md

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R.F.T. KC 85/4	Computers	name image company company_name tabs photos hardware links docs comments related oc_id source KC 85/4 /media/museum/photos/rft_kc85_4_frontview_s1.jpg /companies/r-f-t R.F.T. photos hardware links docs title subtitle text image LARGE VIEW /media/museum/photos/rft_kc85_4_system_s1.jpg title subtitle text image TOP VIEW /media/museum/photos/rft_kc85_4_topview_s1.jpg title subtitle text image LEFT & RIGHT SIDES /media/museum/photos/rft_kc85_4_sides_s1.jpg title subtitle text image FRONT PANEL /media/museum/photos/rft_kc85_4_front%20panel_s1.jpg title subtitle text image KEYBOARD Same poor keyboard as the 85/3, badly conceived (i.e. the Return key) and unsuitable for fast typing. /media/museum/photos/rft_kc85_4_keyboard_s1.jpg title subtitle text image REAR PANEL Same connectors as the 85/3: RGB and TV video output, and bus expansion. /media/museum/photos/rft_kc85_4_rearside_s1.jpg title subtitle text image RFT PLATES /media/museum/photos/rft_kc85_4_labels_s1.jpg title subtitle text image INSIDE Same internal design a the 85/3 /media/museum/photos/rft_kc85_4_inside_s1.jpg title subtitle text image MAINBOARD Compared to the 85/3 version, the mainboard has been completely redesigned. Almost all of the ICs come from former Eastern Europe\ **(1)** U880D CPU, Z80 equivalent\ **(2)** 20 KB ROM chips 2x2764, 1x2732. One of them comes from ST Microelectronics, two others come from Eastern Europe\ **(3)** 64 KB RAM chips, 4164 equivalent\ **(4)** UB855D I/O chip, Z80-PIO equivalent\ **(5)** UB857D display controller chip, Z80-CTC equivalent. /media/museum/photos/rft_kc85_4_mainboard_s1.jpg title subtitle text image DISMANTLED Dismantling a KC85 isn't an simple task, mainly because of the three flat cable connectors which are not removable, also because all the cables are soldered. we gave up in removing the PSU. Repairing this computer shouln't be really easy. /media/museum/photos/rft_kc85_4_dismantled_s1.jpg title subtitle text image D002 BUSDRIVER The Busdriver is an expansion interface which adds four additional expansion slots to the system, resulting in a total of 6 (4+2). Thanks to [WWW.KC-CLUB.DE](http://www.kc-club.de) for this picture /media/museum/hardware/veb_kc85_d002-busdriver_1.jpg title subtitle text image D002 BUSDRIVER Opened We can easily notice the 4 expansion slots and their boards, as well as the dedicated power supply in the right part of the case. Thanks to [WWW.KC-CLUB.DE](http://www.kc-club.de) for this picture /media/museum/hardware/veb_kc85_d002-busdriver_2.jpg title url text Der KC85 - das modulare 8bit-ComputerSystem des veb mikroelektronik 'wilhelm pieck' mühlhausen http://www.mpm-kc85.de/ German dedicated website title url text KC Club http://www.kc-club.de/ Nice german site full of info! title url text UPKA http://www.upka.de/ lots of documentations in PDF (German) title url cover text KC87 & Z9001 MANUALS AND DIAGRAMS, IN GERMAN null /media/museum/docs/couvs/vide.gif **KC87 & Z9001 MANUALS AND DIAGRAMS, IN GERMAN**\ written by Robotron  compiled/archived by Compiled/archived by Thomas Stein\  type of document : PDF\  source : Thomas Stein author date text Michael Weigel (East Germany) Thursday 7th April 2011 The last Computer of the KC series was the KC-Compact in 1990. This mashine is 100$ Amstrad CPC compatible, with the optional floppy disk controler, the RAM was expanded from 64kb to 128kb for using CP/M+ For detailed KC85 informations and documentations look at: www.mpm-kc85.de (german and english language)\ www.upka.de (lots of documentations in PDF, german)\ http://susowa.homeftp.net (one of the maincoders for KC85/4, german only) /museum/r-f-t-kc-85-3 /museum/robotron-kc-85-1-z-9001 /museum/robotron-kc-87 598 url date https://web.archive.org/web/20230603015019/http://www.old-computers.com/museum/computer.asp?c=598 2023-06-03

The KC85/4 was the last one of the KC85/x series. Although it doesn’t look quite different, some internals changed. The whole design changed a bit, and software which used to access hardware directly, sometimes didn’t work any longer, as some addresses changed.

Also, memory was expanded to 64 KB, and the whole memory could be used by software. The ROM increased to 20 KB. The CAOS system offered printer support for most of the available GDR printer models.

There are two expansion slots, which could be extended to four through an expansion set-top.
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Information kindly provided by Stefan Goehler.