BildTel 001 » History » Revision 22
Revision 21 (laforge, 11/13/2023 02:16 PM) → Revision 22/27 (laforge, 11/19/2023 09:52 AM)
{{>toc}} h1. BildTel 001 The Telekom-branded *BildTel 001* was likely the first commercially available ISDN video phone in Germany. {{thumbnail(20231028_114259.jpg,size=400)}} {{thumbnail(20231028_114402.jpg,size=400)}} {{thumbnail(isdn-bildtelefon-picture-alliance-zb-matthias-hiekel-11764519.jpg,size=400)}} (Only digital marketing picture I could find online, courtesy of Picture Allianze / Matthias Hiekel) The specific unit I managed to acquire has been with the "Hochschule für Telekommunikation Leipzig (HfTL)":https://de.wikipedia.org/wiki/Hochschule_f%C3%BCr_Telekommunikation_Leipzig until its closure in 2022. h2. Architecture The system consists of the following parts: * A TV screen with built-in [[BTX__Prestel__Videotex__Minitel|BTX]] decoder (inherited from [[LOEWE_Multitel_TV10]]) * A keyboard + phone-receiver combo (inherited from [[LOEWE_Multitel_TV10]]) * A _desktop-computer-like_ box called the Codec (containing the actual ISDN video telephony part, implemented by AEG/OLYMPIA) * A video camera The BTX Terminal [[LOEWE_Multitel_TV10]] was used as the "user interface" for the device, adding the _codec_ box to turn it into a video phone. h3. Codec unit {{thumbnail(20231028_114437.jpg,size=400)}} {{thumbnail(20231028_120250.jpg,size=400)}} {{thumbnail(20231028_120314.jpg,size=400)}} {{thumbnail(20231028_120334.jpg,size=400)}} {{thumbnail(20231028_120934.jpg,size=400)}} {{thumbnail(20231028_120943.jpg)}} The Codec unit ("Bildeinheit") consists of a variety of different circuit boards: * 1x power supply * 4x "mainboards" stacked on top of each other (two sandwiches of two PCBA) ** top two boards (CODER / DECODER) have a number of DIN 41612 slots for plug-in cards * 6x CODEC ADSP boards plugged into slots of the CODER * 3x CODEC ADSP boards plugged into slots of the DECODER * 1x OUTDIG/OUTANA sandwich, consisting of two PCBA plugged into slots of the DECODER mainboard ** this is the TV output board, generating and digital-analog-converting analog TV signal * 1x INDIG/INANA sandwich, consisting of two PCBA plugged into slots of the CODER mainboard ** this is the camera input board, receiving and digitizing the analog TV camera signal h4. AEG-OLYMPIA CODEC ADSP This board exists 9 times in total (6x for CODER, 3x for DECODER). It hosts a digital signal processor, RAM and some FIFOs. There are no visible differences between the boards; also the label on the GAL is identical. PCB Marking: @1601914L11T@ Connector Marking: None {{thumbnail(20231030_105751.jpg,size=400)}} {{thumbnail(20231030_105725.jpg,size=400)}} {{thumbnail(20231030_105648.jpg,size=400)}} |ADI ADSP-2101|Digital Signal Processor| |VX-8111 10.0000 MHz|Crystal Oscillator| |GAL20V8A (4012-001/2)|GAL| |2x IDT 7201SA25J|FIFO| |2x IDT 7202SA25J|FIFO| |3xCY7C199-45VC|RAM| * GAL image: attachment:bildtel001-aeg_olympia_codec_adsp_4012-001_2_GAL20V8A.jed h4. AEG-OLYMPIA OUTDIG PCB Marking: @2401913L1T@ Connector Marking: @35.103-3030.2 SN. 3051@ top PCBA: {{thumbnail(20231030_110051.jpg,size=400)}} |Brooktree Bt101|Triple 8-bit VIDEODAC| |Xilinx XC2018-100|FPGA 100 CLBs, 1000 Gates| |S-Data SXO-300C 27.00000 MHz|Crystal Oscillator| |3x IDT 7201SA25J|FIFO| h4. AEG-OLYOMPIA OUTANA TBD h4. AEG-OLYMPIA INANA This is the analog input board. PCB Marking: @0202914L1T@ Connector Marking: @35.103-3023.8/01@ {{thumbnail(20231030_214231.jpg,size=400)}} {{thumbnail(20231030_214141.jpg,size=400)}} h4. AEG-OLYMPIA INDIG This is the digital input board, containing the video ADC and support circuitry PCB Marking: @0202915L1T@ Connector Marking: @35.103-3020.2/01@ {{thumbnail(20231030_214057.jpg,size=400)}} {{thumbnail(20231030_214157.jpg,size=400)}} |Brooktree Bt253KPJ|Color Video ADC| |Xilinx XC3030-70|FPGA| |DOC31CC 27.000M|Crystal Oscillator| |3x TI TLC272CP|OpAmp; likely buffers for analog R/G/B| |0900-002/2|SPI flash for FPGA bitstream?| |3x QSL QS8201-15JR|512x9 FIFO| h3. TV Camera {{thumbnail(20231028_115010.jpg,size=400)}} h3. TV / BTX Unit {{thumbnail(20231028_114503.jpg,size=400)}} {{thumbnail(20231028_132851.jpg,size=400)}} {{thumbnail(20231028_133058.jpg,size=400)}} {{thumbnail(20231028_133103.jpg,size=400)}} {{thumbnail(20231028_133211.jpg,size=400)}} {{thumbnail(20231028_133255.jpg,size=400)}} {{thumbnail(20231028_133336.jpg,size=400)}} h4. BTX decoder * EPROM image: attachment:bildtel001_tv10_btxdecoder_16772_074_349_27C010.bin h3. Keyboard/receiver unit {{thumbnail(20231028_114558.jpg,size=400)}} {{thumbnail(20231028_114639.jpg,size=400)}} {{thumbnail(20231028_141412.jpg)}} {{thumbnail(20231028_142128.jpg)}} {{thumbnail(20231028_142246.jpg)}} {{thumbnail(20231028_142251.jpg)}} Actual Cherry keyboard PCBA after full disassembly, ultrasonic cleaning of all keycaps and lots of isopropanol on the PCB, removing what might be decades old coke residue: {{thumbnail(20231029_093033.jpg,size=400)}} * EPROM image: attachment:bildtel001_keyboard_74E84.251U22g_1.0.0_010389_M2764A.bin h2. Connections h3. Codec unit * connects to ISDN basic-rate S0 interface using 8P8C/RJ45 plug * has two proprietary connectors for attaching video cameras * has two SCART connectors (one for audio/video output to the TV) * has a TAE jack for attaching an analog phone for the audio port (connected to the combined keyboard/receiver unit by default) * has another TAE jack (purpose unknown) * has a V.24 interface on a SUB-D 9 connector which connects to the built-in BTX decoder of the TV unit h3. TV Camera * connects to the Codec unit using a proprietary high-density connector that appears to carry both video and power h3. TV unit * has an RF input for TV broadcast signals (PAL) * has a SCART input for baseband audio/video from peripherals (like the Codec unit) * has a DIN speaker output for attaching an external speaker * has a built-in BTX decoder with ** an unused DIN port intended to connect to the [[DBT-03]] BTX-Modem (not used in the ISDN video application) ** an unused centronics port ** an auxiliary V.24 port on a DIN connector interfacing the SUB-D 9 of the Codec unit h3. Keyboard/receiver unit * has a cable with TAE connector attached (connects to codec unit) h2. History The information below is based on a 2023 conversation between Harald Welte and Roland Gaidzik (project manager of the AEG-OlYMPIA Video Phone). Prior to the _Bildtel 001_, there was a research project by Daimler-Benz in Ulm, who developed the codec and created a much larger prototype using a VME-bus computer. The task of the AEG-Olympia (by then also already a Daimler subsidiary) was to translate that research into an actual product that can be produced and sold. The result was the _Bildtel 001_. * More than 100 units (possibly multiple hundreds, but certainly less than 1000 units) were built. ** Most of them were purchased by Bundespost ** a few were given as loner/rental devices ** probably less than 10 were ever sold directly by AEG-Olympia to other custmers * Stollmann (in Hamburg) was responsible for building all the electronics (of the video/codec unit) * The ISDN call control and user interface handling was developed by AEG-Olympia in Konstanz ** 4 people working in Marketing for the product ** 7 people peopel working on R&D * Actual assembly of te final product happened at the AEG-Olympia factory in Wilhelmshaven * Testing/approvals done at a FTZ Facility * The Codec part (even for the final product) was still provided by the research team in Ulm * It is expected/assumed, that the Bildtel 001 already implements the ITU-T H.320 standards, as there was strong desire for this by Bundespost * The _LOEWE MultiTel TV10_ is used almost without modifications. Only very minor softare modifications were made ** It is not expected that the actual BTX/CEPT decoder is used in the product. The UI is generated by the codec unit and presented as analog RGB on the SCART to the TV ** The BTX/CEPT decoder likely simply passes through the keyboard input to the V.24 interface towards the codec unit * The power supply was a standard industrial power supply bought on the market * The video camera camere was a standard part bought on the market As AEG-Olympia went out of business and shut down, the responsibility of the _Bildtel 001_ was passed on to Dornier (back then also another subsidiary of Daimler-Benz). Apparently the Bundespost was very much encouraging Daimer-Benz to keep that project alive and not let it die together with AEG-Oympia. h2. Further Reading * "Thread on the fediverse covering the BildTel 001":https://chaos.social/@LaF0rge/111317641831468838