0073 There can't be many of these in North America: The KC 85/3

[@DanAndersen_]

The japanese newspaper was put in purposely from me, as I had packaging material from my used computer orders from japan. I knew you will recognize it :-)

[@adriansdigitalbasement2]

Haha I figured it was on purpose!! So fun!

[@Sebastian_L.]

Hey Dan, thanks for bringing in some Eastern German technology to Adrians Channel, this is phreaking awesome!

[@horusfalcon]

@@Sebastian_L. Yeah, this is gonna be so cool to see come to life.

[@Supercity2000]

Thank you for sharing this piece of history with the channel, Daniel! And thank you Adrian for sharing it with this community. Fascinating stuff ❤

[@slaquers]

Thanks for sharing history with Adrian and us Dan!

[@starsundsternchen802]

This is so exciting for me. Because I'm from the former GDR and I indeed had my very first experience with this computer. And then the wall break down and I moved on to the the C64 and then to a PC and now I watch this video and a lot of heartwarming memories came back. I absolutely love it!!

[@tiefeXzeitlos]

Yes, we had the KC85s at school, but my first experience was with the Schneider (Amstrad) CPC. My father had brought it with him on a trip to visit relatives in West Germany. 😎

[@abausc80]

Hi Adrian, what a surprise to me to see THE Computer of my childhood on your channel. As far as i know they changed the name from home to compact Computer due to the availabilty and price that system had. In the first years the biggest part of the production went into schools and public Institutions. To close the circle i can tell, that your videos on repairing such old 8 bit machines helped me to get my KC85/3 working again!

[@20windfisch11]

IRM is East-German Engrish for Video RAM. The East-German term was “Bildwiederholspeicher” and this was translated to “Image Recall Memory” (or even “Image Repetition Memory”). The KC 85/2 through 4 had separate Video RAM that could not be directly accessed, from BASIC you had to use special VPOKE/VPEEK commands. Despite the CPU handling all video, so user code only runs in the blanking periods like on the ZX81. The KC line is actually not a clone of a Western design, but an own development loosely based on the TRS-80 and ZX-81. The BASIC was a type-in from a US magazine, altered a fair bit and modelled to be similar to Microsoft BASIC. Edit: the professional computers, PC1715, A5120/5130 were CP/M machines. The AC7100 was an 8086 machine that wasn’t IBM compatible, but could run CP/M 86 and MS-DOS, the AC7150 was a mostly XT compatible machine. At the end of the GDR there was also the EC1834, which was an XT clone.

[@Merilix2]

What you sayd about user code only running in blanking periods is not exactly true. The cpu in the KC had nothing to do with video processing. But accessing the video ram could have caused visual distortions. That was fixed with 85/4 where CPU VRAM access was better synchronized with video hardware within each 8-pixel timeframe.

[@trex70]

Even my Wife is fascinated about this Computer. She is from the GDR and her Mother soldered PCBs at home. She had to feed five children ( her Husband died at an "accident"). Thx for sharing

[@PeterSuethon]

Hey Adrian, this is the first time, i am commenting a video but this time I really couldnt' resist. I've been wainting for such an episode for so long! I even considered sending you such a piece of east german technology. I am a child of this era and also of this eastern side of the iron curtain. So this stuff takes me back to my childhood, when we only had these kind of devices.. or not even these. Sure the others here mentioned it already but I have to say, that these computers were super rare back in 85 so they were only available to schools universities or even the industry. The haven't been sold to private people or only in very very low numbers. They also have been very expensive l (maybe 3500 Mark (GDR currency) while people earned barely 1000 Mark a month or even less). It was absolutely normal to use english for such devices (also TV/Hifi stuff). I never wondered why they used american spelling - good point! Especially considering, that the US was enemy No.1 back in that time ;) PLEASE don't wait too long with an follow up episode where you switch it on.

[@matthiaso57]

There's so much information I want to add .. where to start? I did my first steps in BASIC on machines like that one. The U880 is an East german Clone of the Z80 not a soviet one, and was probably the most important microprocessors in eastern germany and the eastern block. they had versions up to 8 MHz for bigger Computers that ran CP/M , but the slower, substandard ones went into the KCs. the Company that made them went on as Thesys-Intechna and produced Z80 (with a proper license) for quite some time the KCs have no graphics chip, it's all done with discrete logic chips, mostly 555-timers. the main differences betweeen the KC85/1/2/3/4 models were their graphics capabilties. The Kernal of this system is called CAOS - the Cassette Aided Operating System The "Kombinat RFT" - Rundfunk und FernmeldeTechnik (Broadcasting and Telecommunication Technology) was like a corporation of many firms that build electronics. The names contained "RFT", what they made eg "Mikroelektronik", sometimes some socialist idols name (Wilhelm Pieck, 1st President of the GDR) and their location (Mühlhausen). My Father used to work at Sternradio Berlin, the part of RFT that build Radios, Hifi- Komponents and cassette recorders

[@laserhawk64]

I'd love to know how the signaling works on that insane keyboard.

[@Ascania]

@@laserhawk64 Dunno if it was mentioned but the keyboard is based on a remote control chip. The U807D was a clone of the SAB3021, so for the signalling you can look up the latter's datasheet.

[@laserhawk64]

@@Ascania That's brilliant lol. But how'd they get power, data-out, _and_ ground in two wires?

[@Ascania]

@@laserhawk64 The data is AC-coupled onto the power line. Somewhat like phantom power on a microphone. On a very basic principle, it relies on the fact that a capacitor blocks DC but lets AC pass.

[@laserhawk64]

@@Ascania OK that's just insanely brilliant. I was thinking maybe something like the 4011 was somehow being used to open-collextor the power line and I'm pretty sure I saw a huge capacitor in there that maybe powered the circuit while the data asserted active-low, but using AC coupling to avoid that is just brilliant on a whole different level... and positively insane besides :D

[@DanAndersen_]

Another info: VEB FSO Oberlungwitz is an inventory sticker of the VEB (Volkseigener Betrieb - people-owned company) FSO (Feinstrumpfhosenfabrik - fine stocking manufacturer) of the city of Oberlungwitz. So it was part of the computer which was used commercially.

[@adriansdigitalbasement2]

Fascinating!

[@tomsaltner3011]

Otherwise, the arrow keys would look much worse. ;)

[@CM-mo7mv]

Thank you Daniel for sending this in. Even though I am from the GDR, I never came in contact with these devices. When I started out with computers the transition was already in its tracks and the east German stuff was disregarded. (I still own a cassette recorder from RFT though) It is great to see these devices showcased. PS: Viba Nougat, Halloren Classic and Zetti Bambina are also sweets from the GDR that I can recommend 😅 (much sweeter than Knusperflocken though)

[@kargaroc386]

I remember reading about VEBs awhile back. It means "publicly owned company" as mentioned - though I thought it would be fun to see what an english form (beyond what I just said) would look like. And I think it would be something like "folk-owned bedrive", which needs an explanation. Here I have replaced the words with their english cognates. "Folk-owned" has a close enough meaning (people would call you weird but they'd still get it), but "bedrive" is a virtually unknown word in english. Also I don't think its being used properly. The translation of "bedrive" back into german would be "betreiben", not "betrieb". "Treib" and "treiben" are different words in german, but in english they have collapsed into just "drive". "Drive" is generally a verb, but it can be a noun, very occasionally. So its not "to do something", but rather a word about the *concept* of doing something. But the prefix "be-" in english turns nouns into verbs, so it doesn't matter. Either way it certainly doesn't literally mean "company" like it ended up being in german. If you wanted to make this closer in meaning to the german word I'd probably say something like "drivery". A place where things are done. Which, you know, that's one way to describe a company, especially the sort of "company" a VEB was supposed to be, anyway. But that's *changing* things, and if you want to say that, then just say "publicly owned company" like anyone else would. Now I will run away and hide for I am ashamed of my bad linguistics.

[@CM-mo7mv]

@@kargaroc386 yeah, the (official) word company actually is weird in this context, as it would imply they could just act like any company. especially the expanding part. "factory" is more akin to what the "Betrieb" in this sense actually means. I'd suggest translating "VEB" to "expropriated factory", as it usually was a single factory site. (Even though there were exceptions where you had multiple sites, often in the same town.) However usually if the products belonged to a relevant category you would find a "Kombinat" associated, which actually was more like the term "company". It combined multiple VEB to coordinate their production (planning their sourcing, like imported capitalist ICs, and yield ) "VEB" also was cynically read as "Vaters ehemaliger Betrieb" ("previously father's factory") with the actual heirs often employed in the same company that should have been theirs to own. (usually in managing position though)

[@twitzel25]

I have a working one here in the SF bay area. I brought it with me (grew up in east germany and did my first coding on it in school)

[@alxdevier7205]

Tesla was once a Czechoslovak company making all sorts of electronics across whole Czechoslovakia, from tv's to lab equipment, oscilloscopes and electronics parts and even 8-bit computers like Tesla PMD 85-2 and many other things, almost anything electronic. They where extremely popular because they where so wide spread. Almost every household had something made by them, most offen an black and white tv like Tesla Merkur or an radio like Tesla Domino 2

[@andrewclegg9501]

JJ Tesla still make vacuum tubes. RFT did make them, had some in a Marshall clone guitar amp, really good.

[@Toonrick12]

Thought it would of been a Yugoslavian company.

[@scottgfx]

There are some videos here on KZbin of people working with vintage Tesla broadcast equipment, like large studio cameras. The gear looked quote comparable to western equipment of the same era. According to Wikipedia, Tesla AS still exists, albeit smaller. Sadly, in my 2019 trip to Prague, I didn't encounter any Tesla products.

[@AndyTheDwemer]

@@Toonrick12 In this case 'TESLA' in the company name does not stand for Nicola Tesla (although it was apparently the original intention but there were some legal problems with it - or rather, the communist politburo didn't like it) but is instead an acronym for 'technika slaboproudá' - 'low-current technology'.

[@nickolasgaspar9660]

You are right. Tesla is huge in electronics. I have tesla RAM chips in most of my Ataris 8bit. When I visited the country(Czech Rep) and their technological Museum, Tesla was all over the place.

[@timtom9112]

As for the price of this computer in the late 80s: I saw this computer in an East Berlin department stores' in 1987 for a price of 4,900 east german marks. By comparison, a C64 cost around 6,500 east german marks and was only available in second-hand shops (to be fair, these computers were brand new). At that time, a labourer had a salary of around 900 marks a month. The price level in East Germany at that time was completely different from that in West Germany. A typical 3-room appartment had a rent of around 60 marks a month (including heating costs). So these machines were anything but cheap for us ;-)

[@robotnaoborot]

Kinda similar situation in USSR. Computers built by cooperatives were very expensive. You could built computer cheaper yourself(something like en.wikipedia.org/wiki/Radio-86RK but parts were hard to find). It's generally weird how prices were formed in easter block. PIKO railroads or musima guitars were cheaper in Moscow than GDR itself. AFAIK robotron made PC-clones too(and ЕС-ПЭВМ existed too) but those probably costed fortune and were not sold to general population. As for prices - people were able to save to buy such computer because there were not much to buy in shops anyway lol

[@johnsonlam]

Hi Adrian, that STAEDTLER is a rubber head pencil which is very good for polishing oxidized metal, such as Gold Fingers or contact point of switch.

[@adriansdigitalbasement2]

That is awesome! So like a super accurate pencil eraser. Makes sense and I'll definitely be trying it on gold fingers next time I need to clean them.

[@agurdel]

@@adriansdigitalbasement2 The brush at the other end is to wipe the rubber rubbings of your paper.

[@Renville80]

It's been a while since I've seen one of those... back when drafting was done on paper instead of CAD...!

[@Arivia1]

@@adriansdigitalbasement2 And staedtler products are carried in the US, so if you like it you can hopefully find some more. Try dedicated art supply stores.

[@theoriginalbabycub]

Yes, staedtler mars is a stationery brand, so it is a pencil eraser with a brush for brushing away your rubbings. No reason why it couldn't be co-opted as a gold finger cleaner. There were also grey, gritty eraser ones used for correcting typewritten manuscripts before the advent of tippex or over strike eraser mechanisms

[@45thatsme67]

Hi Adrian, what a great presentation, never thought to see this machine being reviewed from someone in the US. In the late 80s I was spending literally any spare time in front of this computer. Together with my friend we were programming only Z80 assembler due to the lame BASIC. There were a lot of fancy features in the firmware or, let's say, BIOS (here called CAOS > Cassette Aided Operating System), which we found out and which were not described in any manual. Anyways, after 35 years things are disappearing from the mind. And, some hints regarding the "big" chips inside: U855 is Z80 PIO, U857 is Z80 CTC and U856 is Z80 SIO (which isn't used inside the KC85/2/3. The IRM stands for "Image Repitition Memory" (like already stated here) and this memory was a bank which was switched in the CPU address space only in order to be written or read from the CPU if necessary. Otherwise, it was switched out of the address space and was just read out by the video interface. If you're interested, I could send you copies of the schematics (hope I can find them, remember I had them in the old days...) Regards, Peter

[@hccaos44]

The IC U807 inside the keyboard is a "processor" for IR TV remote control. The serial data signal output is sent to the computer over the same cable which powers the keyboard. The Datacord is a rare device even in eastern Germany. I got two different of them in my collection. The Datacord is a modified Geracord 6020. These were made for export to western europe labeled as "Bruns Monocord" and sold even in GB.

[@watchmakerful]

Does it use the same principle as the Dallas "One-Wire" devices?

[@BobHannent]

​@@watchmakerfulprobably as they said, just like an IR remote keyboard but instead of driving a diode it just sends the signal over wire. Not two way like a One wire or SPI, but one way.

[@hccaos44]

@@watchmakerful No, its just a clone of the remocte control chip SAB3023.

[@0toleranz]

The data from the remote control chip is ac coupled on to the powerline of the keyboard.

[@ChristopherHailey]

It would be interesting if they used the chip to modulate a signal back up the power wire instead of having it flash an IR transmitter. I would have thought it would have been easier with a 3 wire plug but I guess you could modulate it on top of the power coming in, it just sounds more difficult that way.

[@OriginalKKB]

The tape player is the data version of a tape player originally made for music cassettes. They were quite common around here in the 80s. The weird stylistic black bars on top is where the music player had volume and tone control sliders. The music version could be used with batteries, this one can't, itös just that they used the same plastic moldings for the case and left everything non essential off. Weird that it still has a speaker though. I indeed also started my Computer career with a C64 directly after the wall fell. Never seen a KC85 in a shop, only at youth centers. Oh as far as the english labeling goes, the powers that be were always hoping to export to the west for some hard currency.

[@BastetFurry]

> Weird that it still has a speaker though. Nicht so verwunderlich wie man denkt, irgendwie will man ja nachprüfen ob da das richtige gefiepe kommt und nicht aus versehen die Schlagerparade. ;)

[@paulstubbs7678]

Speakers on computer tape players are handy for cueing tapes and letting you know if there is anything on there etc

[@0toleranz]

The V.24 vas the German nomenclature for RS232 and the IFSS is basically a 20mA current loop serial like on teletypes.

[@tomsaltner3011]

Actually, it was an international CCITT norm.

[@xbmc79]

Congratulations on this very rare GDR home computer. Not even in Germany is it easy to get hold of a model like this !

[@jjock3239]

Special thanks to Daniel for sending you this computer. I have never seen one before, and really enjoyed the video and history lesson. I will never forget where I was when the people started taking the wall down. I was in a hotel room in Amsterdam, watching CNN on TV. As a former military pilot, and being so involved in the tensions between the Soviet Empire and the West, I had a difficult time believing that it was really happening.

[@sven1421]

Got some goosebumps ... Cause KC85/3 was the first computer I worked on in East German school - creating programs in BASIC. Today I own its compedator the KC85/4, which still works. Thanks for bringing a few memories back & enjoying some amazing computer history with us.

[@networkg]

If you need space Adrian, I will pay the shipping for anything you want to send my way ! I am sure most of your fans feel the same way, anything to help Adrian !!! You keep the Retro real, keep it up and we will be forever grateful.

[@dschoene57]

I learned programming on one of these in the late 80s. Once you started programming them in assembler and got to know some of the undocumented port adresses you could do quite a lot with these. They ran at double the clock rate of a C64.

[@another3997]

The C64 used a variant of the 6502 CPU, whereas this uses the Zilog Z80. The Z80 was generally, clock for clock, considerably slower than the 6502. You'll see most contemporary Z80 machines running between 3 and 4 MHz to make up for this. The C64's CPU actually ran at around 1MHz, which was lower than most other 6502 based machines. Eg, the Atari 8 bits ran at around 1.8MHz and the BBC Micro ran at 2MHz, so in terms of raw CPU performance, the C64 was quite slow.

[@Midcon77]

I can't wait to see you get into this one and see what it can do! So intriguing!!

[@tomsaltner3011]

Can’t wait to see you trying this thing out and preserving it. I might check the three machines /2, /3 and /4 - sitting in my basement since 33 years… ;) I remember using an EDAS module (Editor-Assembler) in the mid-80ties as well as a lot of external experimental electronics, doing some quite serious stuff during University times…

[@robfriedrich2822]

16:00 It based on the Geracord GC 6020, has 3 LEDs (where you thought, it would have inputs), one for level indication, has 3 Sliders, one for record level, one for playback level and one as a equalizer from boosting treble to boosting bass. The products weren't equipped with cinch or jack, instead DIN with 5 pins (same standard as MIDI). Tesla is Czechoslovakia. The data recorder version hasn't the features, that a data recorder doesn't need.

[@piwex69]

Now I recall my first and only visit in East Germany in 1988. I was completely astonished by their level of microelectronics. The most advanced eastern block country on this field. Apart from a bunch of copied Intel/Zilog families, they had their own DRAMs on par with Toshiba (for a moment)! While in Poland every kid had a ZX Spectrum/Atarii 800XL or C64 at home, in Berlin I saw a bunch of KC85s in the "house of culture". They were using them to teach programming large groups of young students, just after school hours. It was amazing - the level of planned education into the field, probably comparable to classes of Apple II in the USA as I imagine. BTW, the peripherals (or peripherials as I was calling them whole my life) from Robotron are Hungarian. The tape corder has Czech parts inside (Tesla), so the whole set seems to be the common effort.

[@euromicelli5970]

25:47 that’s an ink eraser in pencil form. I’ve seen them before. They are very convenient for use on typewriters. They have a more abrasive tip compared to a pencil eraser, and they just about scratch off the top layer of the paper - or all the way through, if you are not careful! Were these rare in the USA? The bristles are there so you can sweep away the debris after erasing. You couldn’t use your hand unless you pulled the paper up with the carriage which was inconvenient, and you risk smearing nearby fresh text with the hand, depending on ink quality. Or you could try blowing the debris away instead, but you risk getting saliva on the paper (don’t ask me how I know) and sending the debris inside the typewriter’s mechanism.

[@adriansdigitalbasement2]

I have to admit I never look at these types of things, so I don't know if they are readily available here or not. Typically these types of things are in stationary stores or art stores here -- both of which I never go into. So yeah this is a really useful thing for cleaning up gold contacts!

[@CATech1138]

ink erasers were common on the US...were...I haven't paid any attention to notice them this century

[@CheshireNoir]

@@adriansdigitalbasement2 Those eraser pencils are also extremely useful as a soft abrasive. Great for cleaning IC legs and cartridge connectors.

[@gmirwin]

Some artists and maybe also architects use them, I think. I'm not either, but I know people who are and I believe I've seen them with their stuff.

[@helmargesel3972]

Thanks Daniel for showing East German computer history 💻👏👍

[@AndrewFremantle]

As far as the power supply goes, I think retrofitting a more modern solution is fine, so long as you retain the original parts. Bonus points if you don't need to drill new holes or otherwise alter the chassis.

[@jussikuusela7345]

1:50 the male end is a "Euro" plug, kinda like a compromise designed to fit a plentitude of different continental European 220-240V sockets. The female end likely is an almost internationally used "8" style IEC connector. The Euro plug can even be finagled into a UK style socket, and it fits a "shaver" socket in a wee bit of flippety-floppety way. Shaver sockets are also pretty much a UK thing, found in some bathrooms, fed through a low power isolation transformer each of their own.

[@djsirius27]

The „cassette player“ looks like a reduced Version of a Hi-Fi cassette player my father owned as i was young. The empty fields were for linear potentionmeters for tone -control.

[@DanAndersen_]

The Geracord models are made to work with batteries as well. This model is a stripped down model especially for homecomputers. Other of the 6000 Geracord cassette players have equalizers and work with batteries. It should be convertible pretty easily.

[@adriansdigitalbasement2]

I figured this had various sub-models! It's so well built.

[@hccaos44]

@@adriansdigitalbasement2 It was not the best quality, but designed service-friendly. I had some trouble repairing such drives. Common problems are failure of the auto stop system blocking the drive and a broken gear made of some soft plastics or synthetic material. But none of the 22 geracords in my collection had serious electrical problems.

[@cll1out]

I was gonna mention you can see this cassette drive shows it was designed to be more but was indeed to be stripped down from a model designed for audio playback. Those 3 blank lines you said “styling”? Looks like a volume, treble and bass slider would have been there. And I think more jacks or knobs in that blank plate right above the power lights plus that carry handle that just has blanks in it, as well as the battery feature. In the literature you have it even looks like these features are there in the pictures.

[@TzOk]

ORWO was the brand for photographic films and magnetic tapes. Very famous brand, not only in West Germany. Technically it was the real AGFA, but "World" forbade using them this name, as they kept it for a company in Western Germany.

[@thamessinclair2010]

Coincidentally, the ORWOhaus in Berlin is the location where the annual Deadline demo party takes place. Chances are good to spot KC 85 units on the event (there was at least one present the last time I went there).

[@kamertonaudiophileplayer847]

It has DC motor, so it doesn't matter your AC frequency. It was just audio player and had standard sliders for volume, tone, and record level.

[@Stefan_Payne]

the Powercord is a 2pin Swiss one, that's also called "Eurostecker" aka "Europlug". Its so well loved because it works all over the continent (except Britain). Its the power plug to choose to step on as its rather flat and doesn't hurt as bad as anything else.

[@fattomandeibu]

Weird thing, I'm from England and my house is from the mid 1950s and in pretty much original condition, and there is exactly one Europlug in my kitchen, next to the switch for turning the built in electric cooker on and off. No idea what it's for, as I've never used it.

[@paulstubbs7678]

Those British plugs, which are mostly side entry, so 50/50 if the pins are facing up, must be brutal if you step on one.

[@kaitlyn__L]

@@fattomandeibu fascinating. I knew our electric razor socket was physically compatible with the Europlug, but I've only seen those in bathrooms not kitchens! The spacing is kind of similar to our old "lamp" plugs, too, but those have 3 holes rather than 2.

[@boblambert8985]

@@kaitlyn__L there were 2 prong round pin plugs/sockets in the UK as well. They were used for things like small lamps, or radios.

[@TzOk]

English markings on electronic appliances were quite common behind "the curtain", not only in GDR.

[@Toonrick12]

I'm curious why.

[@TzOk]

@@Toonrick12 It was kind of a decoration. English was a symbol of high-tech, and luxury. Some goods were even produced locally, exported and re-imported with a badge Made in West Germany and German or English labels (in Poland).

[@kaitlyn__L]

@@TzOk that's really interesting, I knew that was the case in say Japan and Korea but hadn't heard that about Poland before! Thank you very much :)

[@EuroScot2023]

One reason was that the Soviet Empire countries were desperate for hard currency and many of these kinds of mostly domestic electronic items were exported - usually below cost - for sale in the West. They were more marketable if labelled up in English and it saved money not producing a German/Russian etc version. The thing about English markings giving the product a 'kudos' at home may have been true but it wouldn't affect the sales since, if you already had to wait a year or more to get one, then, I am sure, you would not have cared if the labelling was in Tibetan!

[@max1zzz757]

When your looking at the chips the 3rd / 4th rows up are actually just the East German / Soviet equivalents of standard 74LS logic chips, the K555 is a 74LS04 IIRC and the DLxxx parts are equivalents of the LS parts with the same number (so the DL074's are 74LS74's). I'm not massively familiar with these parts but just happen to buy a lot of parts for my projects from a Polish supplier which sometimes has NOS tubes of these parts and have come across those numbering schemes

[@1337Shockwav3]

Don't forget the russian K555 series which is compatible to 74LS series which one might encounter in those machines. Whenever you need 74ALS chips it's usually quite smart to go with K1533 series since those are still available as NOS at moderate prices.

[@BeerBullet]

Hello! How cool is that! @43:28 one can see the batch VEB FSO Oberlungwitz - VEB meaning "Volkseigener Betrieb" and FSO stands for Feinstrumpfwerke Oberlungwitz - a factory for fine stockings. It's obviously an inventory sticker. At least the keyboard was used in this factory. Oberlungwitz is a small City in eastern Germany. The cool thing is that I grew up in a neighboring village 5 km away. My aunt used to work at FSO and as a child I visited her in the factory. But I didn't see any computers there ;-) Later - before the wall came down - I got my first programming experiences on exact this type of machine. Now I am a software engineer and it all starts with such a little piece of tech. It's nice to have stumbled across your channel and I'm very curious to see if you can get the computer up and running. Good luck with that!

[@SergiuszRoszczyk]

Technically speaking this tape is almost the same as audio cassette. It is compatible with ECMA-34 recording standard at 63 flux transitions - more or less 800 ftpi. It uses Phase Encoding so technically it is an analog medium but the recording is digital. It was used with East Germany Robotron tape devices and Polish Meramat PK-1 and PK-3 tape devices among many others also on US market

[@deepblue25]

It must have been 1988 or 89 when I was with my primary school class at the semiconductor factory in Frankfurt an der Oder (East Germany) and we had our first contact with this very computer. As a child, the thing seemed cool to me, but thanks to West German television, you could see at first glance that it wasn't high end - even as a child. To be honest, I mainly remember the really horrible keyboard. 😅

[@djsirius27]

I‘m also a proud owner of a KC85/3. I remember as a kid me and my brother had a „computer course“ during our school holidays and we learned on a KC85/3.

[@JamieMPhoto]

An Orwo tape! Parts of Orwo have survived, some once again operating as Orwo. They have ramped up in making camera film again, too. They've been doing black and white again for a while in some form, but color is making a comeback, too.

[@DanAndersen_]

The mini-itx power supply or using the "test-psu" is both a viable way. It's both fine.

[@mizterwizerd]

Yeah, save the original obviously, but putting in an modern safer PSU to protect it since it may be hard to crowbar it like you would with vintage hp metrology equipment

[@GYTCommnts]

Fascinating! More of this komputer, please! Hope there are some games for it to showcase. Games always show the best capabilities of computers, at least for me.

[@Jonny_O]

The Datacord’s “stylistic embellishments” are indeed blanks. A number of German tape players used this same chassis, including the GC-6020 and the Geracord 6000 (also branded RFT).

[@adriansdigitalbasement2]

neat yeah just looked those up-- it looks like volume and balance control.

[@hccaos44]

On the 6020 and other mono models there are sliders for volume, sound and record level. The stereo deck version 6030 has sliders for left and rigth recording level and headphone volume - and no speaker.

[@BerndTheBrick]

Beside the Datacord there was a Geracord. While the Datacord is a lower version for datasettes only the Geracord is a normal cassette reorder and had sliders where these black plastic coveres are here. The english words were used for two reasons. First it sounded modern and from western countries and second they thought it could be sold in these countries. 29:45 My parents still have a KC87 which looks identical like this "Keybord" the keys are extremly painful to use.

[@BigRonRN18]

I believe I remember seeing a pencil like the one with the brush on the end before when I was a child and it was for erasing typewritten characters in the time before White-Out or Liquid Paper. The white "lead" is the actual eraser but then you use the brush to free up residue that may be stuck to the paper. Obviously, this would only be used for a few characters and it wasn't perfect but harder to notice after photocopying.

[@waxore1142]

The thing with the brush on it is an eraser pen. Typically for people that do art with pencils but it's great for cleaning contacts and brushing the eraser residue off

[@belzebub16]

Even though I'm from (Western) Germany, I've never heard of or seen this computer, what an exciting mail call item! 👍 And you reading through the german books is a nice bonus 😊

[@1337Shockwav3]

Typical of westerners to be ignorant of the GDR ^^ It's a curious architecture and one of the very few original German computer designs, which is why I dug into the machine a few years ago despite being born and raised in the FGR.

[@piede837falso]

Hi Adrian, the blue pencil with the brush is an eraser. I remember using it in my art class to erase little mistakes without ruining all the drawing. I think there are also other uses for that. Hope that was helpful, and thank you for all your content

[@catriona_drummond]

I was one of the clamorers in 1990, spent all my converted savings on an Amiga 500 as soon as I could get my hands on one.

[@skillaxxx]

And I bet you loved it to no end ?

[@catriona_drummond]

@@skillaxxx I did. For the first two years though I wasn't even aware that you can commercially buy software. :D

[@TheMason76]

What a funny coincidence 😆😆😆. I saw the preview of your video and noticed that i had the same cassette recorder as a child (as i thought). Then i went, due to a nostalgic journey impulse, to search for this cassette recorder, and i found it. As Daniel i grew up in west germany (near the border of the nederlands). So i wondered why this cassette recorder came from the GDR. I found, that they also made an export version of this recorder, the "Monocord 6020". Funny that i had one of these. So many memories ... 😊 From the KC85 i heard many years later. But very funny how some things i see on you tube makes me remember about beeing a child and using all that stuff. And also the Videos you make which take me back in time. Thank you Adrian.

[@eazyliving]

You should make some kind of gathering the next time you're in Germany. I'd absolutely be there! We could visit the Haribo factory, which is ~40km from here.

[@adriansdigitalbasement2]

Yeah it would be so fun to meet some of my German fans! Germany is the #3 country for views for my channels after The USA and UK, so I can tell the retro community in Germany is huge! (Considering language is going to a barrier for many people when watching English videos)

[@belzebub16]

@@adriansdigitalbasement2 That would be so awesome! I'm going to a retro convention myself in 2 weeks near Hamburg, of course none is as big as the VCFs you have, but still 😊

[@KolliRail]

@@belzebub16 considering your comment is 5 days old you are possibly talking about Saturday the 2nd of Dec? Near Hamburg maybe the "connected' in Uetersen and we will meet there???

[@belzebub16]

@@KolliRail: That also sounds like good fun, but on the same weekend the LuheCon is happening in Winsen (Luhe) so that's where I will be 😊

[@Colaholiker]

@@adriansdigitalbasement2 The language barrier is smaller than you'd think. Especially with your target audience and when it comes to watching videos. The percentage of people speaking English at least to some degree in Germany is pretty high. It has been mandatory to learn English in school, and even before it was mandatory, it was already really common. And just think about it - when people watch your videos, they see what you are talking about, which already helps a lot. Then, it is a video, so they can rewind at any time and listen to it again, possibly add subtitles and if all else fails try to use an online translator. Both your clear pronunciation and good audio also help. Most likely some of those watching your videos here in Germany may not feel comfortable having a conversation in English, but of course that would be a totally different story. Long story short, I totally support the idea of a gathering in Germany.

[@BottIsNotABot]

This looks uber cool, looking forward to see a video on you having a play with this computer!

[@dhpbear2]

13:05 - That translates to "Tested at 63 FW/mm". I believe that to do with the magnetism of the tape. "FW" stands for 'Femtoweber'

[@ipaschke]

That would normally be fWb/mm and I don't think that makes much sense. I think it's probably "Feldwechsel/mm" (flux transitions/mm, like the more common BPI - bits per inch).

[@dhpbear2]

@@ipaschke Ah, thank you! My German is non-existent, even when it comes to names of UNITS! :)

[@Ole-vu9yj]

@@ipaschke This is right. 63 FW/mm * 25.4 mm = 1600 BPI

[@fordonmekochgalenskaper5665]

One thing with this old computers that run basic is that the manual is very helpful to understand the computer with all the test program written in them and it's easy to understand the difference between brands.

[@watchmakerful]

The "VEB Mikroelektronik Wilhelm Pieck" company in Mühlhausen also made several models of pocket electronic calculators.

[@BanazirGalpsi1968]

In usa, my dad had one of those paint brush looking eraser accessories as well as some very hard erasers, for typewriter output. One thing also im curius about, changing topics, is the BASIC comands for graphics. Even in usa every computer in spite of BASIC had totally different graphics commands. In PAL im sure its no different....

[@PeteWord]

Wow! That was a good one! Thanks Adrian and Daniel!!!

[@glenn9854]

Going on tangents is what makes Adrian so interesting.

[@Drew-Dastardly]

Oh wow STAEDTLER pencils - that is a blast from the past, 1980's. My favourite troll teacher when anyone said "Sir, I don't have a pencil" - his retort was "WELL USE YOUR SPARE ONE BOY!". Super strict headmaster but I appreciated his strict humour a lot even being the subject of it from time to time. (Most kids didn't get it) STAEDTLER HB was the school pencil. I'm glad they are still in business.

[@cheeseparis1]

So looking forward to the next video! Thanks for sharing your enjoyment discobering this amazing machine

[@NoNameForNone]

Not even finishing the video I'm liking the candy choice 😆. The person who did that layout on the top board (when first opening) loved his/her job. And I can tell you by experience that the z/y is not going to bother you normally unless someone decided to use irregular words somewhere. We use querty and I use a lot of quertz keyboards and it is a lot less annoying than azerty the french use (and some multi lingual belgians). Except for the strange location of the | or \ sometimes.

[@Dawwwg]

What a cool, expandable and (at least) capable looking Home Computer, looking forward to the next video on !

[@CandyGramForMongo_]

Modify as little as possible. Prefer mods that can be easily reversed. What a great find!

[@howardsmiller]

Back in the 80s I worked for Honeywell designing heating controllers. We had a range that powered and transmitted data between the boiler unit and the wall-mounted room controller over two wires. I'm trying to remember how it was done but I can't recall it being particularly complicated.

[@nexiagsi16v91]

During development, the series was called HC (Home Computer), but it quickly became apparent that large numbers would never be achieved. The costs were extremely high and a lack of components was also a reason. Therefore the computers were renamed KC (Small Computer, so nothing for home). They were almost only used in companies and very rarely in private environments. That was also due to the price. Just the computer costs about 4 months' wages. In West Germany 1985 a C64 cost around 50% a month's wages. So, take good care of the "clutter", it is also rare here in Germany, especially in this good condition.

[@mattelder1971]

25:58 that's an eraser that you can sharpen in a regular pencil sharpener. I've seen them in schools and art stores pretty much everywhere, even here in the US. The brush is for wiping away the rubber residue.

[@klaatubob]

13:06 that's the flux value for the tape. It's used to set bias and eq and determines the max signal strength you can hit it with.

[@boelwerkr]

The keyboard communicates by pulling down the power line a little bit. This works good enough if you transfer the data in one direction only. The Computer side looks for the lower voltage. It's not much only 0.3V - 0.5V. A big capacitor reduced the noise produced by the ICs.

[@EuroScot2023]

It's just 'phantom powering'. Very simple and all quality capacitor/condensor microphones use the technique.

[@maro_from_germany]

As others have mentioned: In the 80's English became more and more common for more modern consumer goods (and other devices), even in East Germany. I had English in school starting in 5th grade. The quality and spelling was not exactly uniform (or correct). You might have noticed the spelling "MEMORYSELECTION" without a space on the device itself (which is pretty much how compound words in German are written), but the manual correctly says "MEMORY SELECTION" (as a native English speaker would write it). I also have the remnants of an East German drum machine where the headphone control is labeled "HEAD-PHONE" which a dash.

[@davidellsworth4203]

10:47 - The serial number of the computer is 006851, not 006854. (Commenting this for completeness's sake, not that it makes a big difference.)

[@jensschroder8214]

In East Germany, companies were merged to form VEB. For example, a VEB that took care of building electronic devices, record players, HIFI devices, cassette recorders, TVs, semiconductors and computers. The data recorder looks like an audio cassette recorder that has been adapted for use on a computer.

[@steffenjachnow8176]

> "In East Germany, companies were merged to form VEB" Not quite right. What you mean, is a "Kombinat" (combine / combination) which could contain many VEBs. A VEB (volkseigner Betrieb = people owned company) was just an single state owned company.

[@frankowalker4662]

That is so totaly awesome. Loved looking at the books. I'd be intrested to know how the keyboard works. Seems very clever.

[@senilyDeluxe]

There's a few vintage video games consoles that use a similar trick. The RCA Studio II and the Atari 5200, they are both powered over their RF cable. With these, I understand how they work. The RF signal is capacitively coupled to the power line and thus modulated onto the power signal. To make it work, the signal should have as little low frequencies as possible, otherwise the voltage regulator(s) will attempt to fight the data signal. With RF, that's easy as it's at around what was it 70MHz? But with a keyboard at maybe a few kilohertz, dunno if that's possible without annoying the voltage regulator. Wouldn't be surprised if it feeds off the 12V line through a big pass resistor, maybe has an internal 5V regulator and then modulates the data with only a few volts, in which case the signal can be picked up through an analog comparator (easy circuit), or modulates it as FSK (Frequency Shift Keying) at high-ish frequencies (not hard to decode; won't need a pass resistor). If you've got a chip fab (they did), you could design a keyboard matrix decoder that outputs keys as an FSK serial bitstream and another chip that can just decode that with a few external components. Wonder if anyone has better half-knowledge about this than me. I'm pretty much using the little I know about analog electronics (I'm really good at digital electronics) and pretty much guess how the stuff works. I haven't looked inside either of these consoles. I'm thinking "this is the only way I know works and it also happens to make sense so that's probably how they did it".

[@frankowalker4662]

@@senilyDeluxe That makes sense. Similar to a phone touch tone keypad but using RF instead of AF. Thank you.

[@EuroScot2023]

It's 'phantom powering' just as you will often find on quality microphones. Why use 4 wires when all you need are 2.

[@maro_from_germany]

The KC 85/3 (and its various siblings) were an effort of the GDR to catch up to western technology and knowledge. Asianometry did a (IMO very good) video about the GDR semiconductor industry that talks about some of the events that lead to this. In a nutshell: The GDR had a passable semiconductor industry in the 60's but dropped the ball in the early 70's (more or less for political reasons). In the early 80's it became obvious that the whole computer thing (and highly integrated semiconductors) wasn't just a fad; and now a desperate race started to close the widening gap.This involved both chip manufacturing and of course computer technology as a whole. When The Wall came down in 1989 there still was quite a way to go; but those efforts paved the way for some of the more current developments like the emergence of "Silicon Saxony" (with various chip manufacturers having set up shop in and around Dresden). Germany (both West and East) was always quite good when it came to educational concepts; hence it didn't take long for general purpose programming literature to appear. I still have that "Kleincomputer" book myself. At the same time a number of home and educational computers was developed. Among those were the Z9001 (which later became the KC85/1 and KC87 - and yes: the KC85/1 was a completely different machine compared with the 85/2 and 85/3), the other KC models, the Z1013 (a SBC with a very weird membrane keyboard), the LC-80 (I have one of those) and the Polycomputer 880. As was already mentioned those usually went to schools and universities (or other "official" organizations: when I was serving in the army we got a Z1013). I was never particularly interested in any of those because the software available for them didn't fall into my area (MIDI and music). 16 bit technology was harder to come by since 16 bit chips and computers were falling under COCOM rules (in other words: it was prohibited to export them to the Eastern bloc). Still quite a number of Amiga's and Atari ST's found their way. But naturally those cost an arm and a leg...

[@PeterSuethon]

I completely agree with that. It is then more interesting, how the 8086 (as a 16bit) came into the game.. afaik there was a russian clone but the actually existing machines did have a western clone (Siemens HL). So the embargo was weakening during the late 80ies so smuggling became a serious source for "mass" production.

[@srmeister1]

i live right next to the MME Chipfactory which is still producing chips for automotive industry today. All the chips marked "MME" in those GDR machines were produced here. MME stands for Karl-Marx Mikroelektronik Erfurt. What a name :) Today its called X-Fab.

[@maro_from_germany]

The DL series logic chips were all coming from Halbleiterwerk (meaning semiconductor factory) Frankfurt (Oder) . en.wikipedia.org/wiki/Halbleiterwerk_Frankfurt_(Oder)

[@krnlg]

Wow what an awesome computer! So interesting, especially that keyboard interface! Really looking forward to seeing whether it works! 😃😃

[@TSteffi]

The swapped z/y keys were such a pain back on DOS. Can't count how many times I tried to open a .YIP file because MODE wasn't loaded.

[@matthiasklemens2173]

Greetings from Mühlhausen. Yeah right, the City near Erfurt where these where build. I hope it is in working condition. Mine are all, and i have a lot of them. The next one Kc85/4 has also a disk drive, that is very rare, cause they don't build a lot until 1990....

[@Andyk76]

Great. Even though I am from West Germany I own one of these. Also a KC 85/2 (basically almost the same as the KC 85/2 but without integrated Basic. You needed a expansion module for that). And I do own a KC 87. The competing model to the KC 85. Even though there was no real competition. They were pretty capable and expandable for the time.

[@1337Shockwav3]

It's a curious architecture, being born and raised in the FRG ("West Germany") I wonder why people barely care about those machines ... probably because of the very limited supply of games? I used to have a fully expanded KC85/4 with a modernized version of the floppy drive, but lost interest at one point since besides CP/M and 'productive' software there are maybe 2-3 interesting games for this machine. I'm quite happy to see the demoscene has slowly taken off for this machine.

[@EuroScot2023]

Probably very few games since the supply was so limited - and they were so expensive - that few got into home use.@@1337Shockwav3

[@vhfgamer]

Classic square ceramic capacitors from the soviet union. I've seen a lot of those watching Shango066''s videos on old soviet transistor radios.

[@matthiase.1747]

The yellow-brownish ones came from east germany. The russians hat red ones as seen inside the keyboard.

[@tramadol42]

The Robotron printers shown in the photos in the book were also sold in Western countries under different brand names (to disguise their origin). In Western Europe they were sold as " Präsident Printer", with various connection interfaces that made the printers emulate 1:1 IBM, Epson, or Commodore printers. I still own a working Präsident 6113, with both IBM NLQ and CBM MPS 803 Interfaces. It's a beast, loud as hell...

[@koblih69]

Glad to see Tesla brand on the speaker - Greetings from Czech Republic. Tesla, by the way, was founded in the Czech Republic long before Elon Musk was born (1946) 👋

[@djcmike]

Looking forward to the video on this little gem :)

[@der.Schtefan]

Whereas we associate "soviet" stuff with hacky stuff, one should not underestimate East German (and for that part Hungarian) computer, chip manufacture and electronics design. They were top notch, partially thanks to Zeiss of east Germany being able to copy pretty much every western chip by de-lidding and doing what they do world class best: microscopy and litography. The manufacturing standards were only trailing a bit behind the west, and quality control was top notch. Many western German companies manufactured their premium products in the east, full with labels, and just sold it in the West as "made in Germany". The English labeling most likely is a result of this device being destined for the export market.

[@stevethepocket]

Now you've got me wondering how many things branded as "made in Korea" secretly meant North Korea.

[@ffsireallydontcare]

@@stevethepocket I went to Korea on a corporate "junket" where we visited the DMZ. There's a purpose built "city" for exactly this, complete with hi-rise and factories, on the N-K side. They'd bus S-K employees over the border to supervise N-K workers building all sorts of stuff both for export and use within N-K. This was where one of the hi-rise office buildings (liaison office) was destroyed by Kim a few years ago (suspected to be done by his sister) as a show of defiance against the Seoul and I think the city is not currently in operation.

[@kargaroc386]

The "soviets" actually had some interesting computers earlier on (I recall reading about one minicomputer in particular which was quite innovative but got shut down) but by the 80s it looks like almost all of their computers were copies of Western designs. The Electronica 60 of Tetris fame was a PDP-11 clone. This uses a Z80. There were more ZX Spectrum clones than you could count. In the GDR, VEB Robotron and others cloned all sorts of systems, from the System 360 to the VAX, as well as the XT. The software tended to be a bit more original, but there was plenty of cloning going on in that department as well. Its worth noting, they didn't really have a western IP law system. No good communist would've seen anything wrong with copying software anyway.

[@EinChris75]

"Steuerbus" is control bus. So like write enable, chip select or hardware interrupt lines. The KC 85/1 was an all in one system like the C64. So you don't just see the keyboard, but the whole thing.

[@simonweel7971]

Those cassettes with the notch - we used them way back with our Everex backup tapedrive. It wouldn't take 'normal' audio cassettes.

[@HighlandSteam]

The fibreglass polishing pen is very common in the UK. I have been using them since the 70s.

[@andygozzo72]

those black strips on the front of the tape unit likely cover slots for slider pots, in a normal 'audio' version of it, they likely just adapted one for computer use with fixed volume and tone output

[@purrator]

There are somewhat bizarre photos of the PC1715 being paraded through the streets of East-Berlin during Berlin's 750th birthday celebration in 1987 (a google for PC1715 and parade should get you there quite easily) Also FBAS (Farb-Bild-Austast-Synchron-Signal) is just German for CVBS or, simply put, Composite Video

[@vanhetgoor]

The KC85 is a very interesting computer. Built in East Germany were all resources were almost sufficient, but not quite. The 2-wire keyboard is interesting, they took a chip from a remote control and made the keyboard around it, the signal is modulated on the 12 Volt power to the keyboard. With almost no effort it could have been made wireless, but then you had to carry a 12 Volt car battery with you.

[@horusfalcon]

I look forward to other videos about this little unit from the GDR. (You do, man, you get all the good toys!)

[@ThePoxun]

Centronics was a printer manufacturer. They had a standard connector/interface that is effectively just a 'normal' parallel printer port and a specific protocol/control set for switching between graphics and text mode and Centronics compatible printers (from many different manufacturers such as Brother) were quite common in the 80s. BBC micros for instance were usually connected from the printer port on the computer to a Centronics compatible printer.

[@williamsquires3070]

Hi Adrian. That cassette player probably works on battery and line power much like some of those little portable TVs you have, but the battery pack was external and used the same plug (at the cassette player) as the line cord would, though there should be an interlock so you can’t plug in the line cord when switched to battery, or there’d be a loud bang and lots of magic smoke would come out!

[@SvenKillig]

26:08 A Präsident printer from VEB Kombinat Robotron! I owned the 6320 model with the C64 interface module as a teenager. Built like a tank :-D

[@PeterSuethon]

yes and loud as a tank ;) (I had the same setup)

[@AlexLuyckxPhoto]

I don't recognise the tape, but I recognise the brand, ORWO, or ORiginal WOlfen, created out of the original Agfa plant in Wolfen. They produced both photographic and movie film stock but also branched into magnetic media. The company still exists today and produces traditional B&W films.

[@bentbilliard]

The Pencil with the brush at the end is an eraser pencil. The brush is to get rid of the eraser fuzzles on the paper. I had one when I was a kid.

[@T3hBeowulf]

20:50 - BigClive refers to a specific set of adapters as "death-dapters". The multi-country adapters made to accept whatever plug and convert them to the UK or US plugs are particularly dangerous because they leave exposed pins and gaping holes uncovered when plugged in. They often lack fuses and any sort of voltage conversion, opening the user to opportunities of "spicy" electrical interactions. Your adapter is probably fine in that it is a single-purpose pin converter.

[@MarekZwick]

When I was a child used this computer in a computer club at my school in East Berlin back in the late 80s. We had 3 to 4 KC 85/1 (awfull keyboard) and KC 85/3 (at this time I though ok keyboard) and wrote Basic programs and played games (maybe the ones from the “Spiele-Kasette”). There weren’t that many produced, so I don’t know if you really could buy one for yourself and they were very expensive (I think like 3-4K DDR-Mark, which could something like half-year earnings) . I think the U880 used in this computers was a clocked down version (which couldn’t be used in the BC Business Computers)

[@1337Shockwav3]

I've met Horst Völz who wrote the Texor word processor for the KC85/2 and up (even have a signed copy on tape) ... according to him not only the keyboard of the KC85/1 was junk ;)

[@MrJakeTucker]

Around 34mins 40 secs in. Adrian wonders if FBAS is sound maybe. I vaguely recall that FBAS, as seen in a diagram in the system book, is composite signal. It's next to RGB and Antenne (RF). I haven't seen composite referred to as FBAS for years though.

[@SPARTAN_Cayde-26]

As a lover of eastern block things, that DDR made computer is so cool to me!