LEGO is among one of the world's most recognised brand names. Most people would be familiar with LEGO's passive building bricks but how familiar are they with LEGO's electronic products? When I think about electronics and LEGO I think about the upper end of the Technics range (more complicated LEGO sets based around gears, pins, rods and beams) or the MindStorms products (sets revolved around the concept of a small programmable controller allowing for robotic type creations). However, electronics and LEGO go back a long way, long before the release of MindStorms. In fact it was back in the mid 1960s that kits with motors began. As a kid I remember being very impressed by the LEGO light bricks and motor powered vehicles. It was something special compared to the other generic LEGO parts. You have to remember that going back a few decades the variety of LEGO building blocks was not like it is today and Technic sets were not all that common. These sets were powered by a battery pack (3 x 1.5V cells) resulting in the 4.5V standard which lasted in production until the mid 1990s. The sets included a motor or a light or both. It wasn't until around the mid 1980s that LEGO injected funding into extending the electronic product range and in collaboration with MIT (Massachusetts Institute of Technology) processes were set in motion that resulted in some fantastic products. These products are not limited to but include the initial Technic Control Center (4.5V) sets released in 1986, followed by the Technic Control Center (9V) sets in 1989, Control Lab in 1993 and then leading into the very popular Mindstorms from 1998 which is currently into its forth generation of products. LEGO's first programmable product, the Technic Control Center (4.5V), was built around the long running 4.5V standard and harnessed the processing power of the more common computer platforms of the time (Apple II, BBC Micro, Commodore 64, IBM-PC, MicroBee and a few others). Several commercial programs were available for controlling the equipment, LEGO Lines, LEGO TC Logo and then later LogoWriter Robotics.
The use of LEGO for home robotics started before 1986. In 1977 LEGO Technic was introduced and within a year gearboxes and better motors were available. Also from the mid 70s the micro computer market made great technological strides and so by the late 70s using LEGO for home robotics was certainly possible. However this was still the domain of the electronics enthusiast as controller\interface boards needed to be hand built and the computer manually programmed. What LEGO did with their first programmable product was to jump on the bandwagon of bringing this technology to the masses. It allowed a working robotic contraption to be built within hours not weeks or months and basically by anyone who could read a book and follow instructions.
The Technic Control Center (4.5V) series includes sets [9700-1]: Technic Control Center, [1090-1]: Technic Control I and [1092-1]: Technic Control II. However these are just the Lego brick sets and instruction cards. It gets very confusing because like many LEGO sets aimed at the education sector, to get anything going, you need a variety of different packages. In this case you would also need the computer interface card, a controller board, software (LEGO Lines, LEGO TC Logo or LogoWriter Robotics) and the teacher's guides for programming examples and tutorials. All these were sold separately. There were some sets called starter kits, such as the [951-2], which bundled all of this together. The 4.5V control series is not to be confused with the 9V control series which came after it. It is easy to do because the titles are so similar (9V series :- [8094-1]: Control Center, [8485-1]: Control Center II, [9753-1]: Technic Control Center I and [9752-1]: Technic Control Center II). The static bricks are compatible between the series but the electronic parts are not. The best way in trying to identify these sets is through the LEGO set numbers which I have enclosed with square brackets. Sometimes even this is not enough ie sometimes the Technic Control Centre set is denoted as  and sometimes as [9700-1]. Also, some of the old LEGO numbers have been reused and now refer to newer Lego items.
I was interested in getting one of these sets up and going on my Apple II computer but the asking prices for the full kits was far more than what I wanted to spend. For this to work I needed to find a different source. After scanning the web every now and again over several months I came across a controller board which is the most critical part of the setup. The interface cable was missing and the power adapter did not suit my power sockets so by just taking the controller board saved me some shipping costs. The cable was easy to make up and I found a suitable power adapter in my junk box. To connect this to the Apple II I needed an interface card. I started the process of building the LEGO interface card myself as there is not much to it. It so happened that I found one listed and bought that instead. I purchased a few electronic LEGO parts off ebay and used my existing LEGO bits, not that I had much that was suitable, to build a few freestyle contraptions. This kept me happy for a while.
The Technic Control Center sets were only released via LEGO's Education arm (dacta) so in its day you were not going to find one of these sets at your local toy store. To begin with I wasn't looking at getting an entire set because I assumed the parts were difficult to get. How wrong I was. These kits were sold in huge quantities so there are plenty of the parts still around. Even the most useful part, the motor, by being available in many sets going back to the 1960s is still readily available in large quantities. The only problem is that the majority of these kits have been split up and sold off in pieces. The parts are obtainable but just not from one single source. I was able to obtain all the parts I needed for all three sets ([9700-1], [1090-1] and [1092-1]). To keep costs low I obtained mostly used parts and removed any duplicates between the sets. I still ended up with about one thousand pieces of Lego and even with shipping costs taking up about a quarter of all costs it still ended up being a fraction of the price that I have seen some kits go for. At times it was frustrating but just like most things, if you put in the effort (for the most part) you will be rewarded. Obtaining LEGO this way is not for everyone as it is a very time consuming process. Having purchased used parts as opposed to getting expensive new in the box sets I'll be more inclined to get the LEGO out and use it. I think Emmet would give that the thumbs up (if he had any that is). The following is a write up of my findings and challenges. I hope to complete it one day and keep it as a resource for others who wish to do the same.
The following is a breakdown of all the components of the system :-
1. Computing platform.
First thing needed is a computing platform. No points for guessing that my platform of choice is ... the Apple II. If an Apple II platform is used then it has to be one of the Apple II models that has an available bus for the interface card to slot into. That is if you want to use the commercial software that is available for the sets. Technically you could use the Apple IIc to control the LEGO but you would need to create a serial to parallel adapter and write your own software. If you don't have a real Apple II but you do have the Lego set pieces and the controller board then check out these websites https://lgauge.com/article.php?article=technic/articles/LEGOInterfaceA and https://burf.co/blog/2012/11/24/lego-dacta-interface-a-vb6-control/. They shows you how to hook up to a modern day machine. Alternately, if you wanted a more compact solution you could interface straight into the LEGO controller by using a microcontroller board.
2a. Software - LEGO Lines.
LEGO Lines is a software package that allows you to setup lines of commands which are then passed through to the controller board in sequence.
The components of LEGO Lines are as follows :-
[950-035] LEGO Lines Teacher's Pack and Disc (APPLE II)
Just for reference purposes  is the BBC Micro version,  is the Commodore version and  is the IBM-PC version.
The Commodore 64 version of LEGO Lines software can be found in the Extra Info section below.
Since the Logo based software packages only came out on the Apple II and the IBM PC this software package was mainly used on the other computer systems because they didn't have a competing product.
The 5.25 floppy disk images and the manual can be found here :- https://docs.google.com/open?id=0B5PVarmqxaOnbVVDbmxVSk0xT0U
Only the "Teacher's materials" book is provided as it contains the contents of the "Resources booklet" and the "Classroom materials" plus a whole lot more, including a section on how to talk to the controller using Applesoft BASIC, machine language or LOGO II.
2b. Software - LEGO TC Logo.
LEGO TC Logo (TC stands for "Technic Control") is a cut down version of the LogoWriter software package but with the addition of the right extensions to make it interact with the interface card and ultimately the controller board.
The 5.25 floppy disk image and the manuals can be found here :- https://docs.google.com/open?id=0B5PVarmqxaOnRkRERnN1VUx4cjg
The components of LEGO TC LOGO are as follows :-
 Building cards for set [951-2] ( equivalent IBM-PC version)
 LEGO TC Logo - Teacher's Guide
 LEGO TC Logo - Reference Guide
 LEGO TC Logo - Quick Reference Guide
 LEGO TC Logo - Getting Started
 LEGO TC Logo - Teaching Turtle
 LEGO TC Logo - Making Machines
or when purchase separately
 LEGO TC Logo Teacher's Pack and Discs (APPLE II)
 LEGO TC Logo Teacher's Guide (APPLE II)
 LEGO TC Logo Student Guides (APPLE II)
 LEGO TC Logo Reference Guide (APPLE II)
2c. Software - LogoWriter Robotics.
LogoWriter is a software package based around the Logo language but it contains a different working environment to other Logo implementations of its time. As well as the Logo interpreter it contains a word processor and allows for better integration of graphics and text. The first version of the software was released in 1986 but it didn't get the LEGO control extensions until the release of the LogoWriter Robotics version in 1988.
The components of Logowriter Robotics are as follows :-
 LOGOWRITER Robotics - Apple IIe/IIGS 5.25" ( equivalent IBM-PC version)
 LOGOWRITER Robotics - Apple IIe/IIGS 3.5" ( equivalent IBM-PC version)
If any one has the software and/or documentation for this software package then please contact me.
3. Computer interface for Apple IIe/IIGS -  interface card.
It's the controller board that does all the important work when it comes to controlling the LEGO parts and not the interface card. Instead of building different controller boards for each of the computing platforms, like what fischertechnik did with their competing robotic products, the designers here decided that they would build a universal controller board which was the workhorse of the set then develop a simple adapter for each of the computing platforms. Therefore the interface card is an Input/Output card that acts as an adaptor to the controller board. The beauty of this design is that after all these years it makes the LEGO version so much more obtainable than the fischertechnik alternative.
This card comes up on ebay every now and again but it is usually priced way above for what it actually is (probably because it has LEGO printed on the card and is for an Apple branded computer). If you have purchased the LEGO kit for one of the other computer platforms and can't get the IIe/IIGS interface card version or you just want to build the card yourself then please find the schematic here.
Instructions on how to install the card and test it can be obtained here :- https://docs.google.com/open?id=0B5PVarmqxaOnVl9Qb2NleWQ3QzQ
Just for reference purposes [9771-1] is the IBM-PC version of the interface card. The BBC Micro version was just a cable  and so was the Commodore 64 version .
The Commodore 64 interface cable schematic can be found in the Extra Info section below.
4. Controller board -  or  LEGO Interface A.
The controller board, also known as the Interface A (Interface B being the controller board for the 9V series), contains the model number  or .  is the older of the two and contains LEDs that have a rounded top. The other contains LEDs that are flat on top and are flush with the casing. You will usually find these in the form of a kit [1093-1] or [9750-1]. These kits include the controller board, power adapter and the connection cable. If you can only get hold of the controller board itself then that's ok. The interface cable is easy to make and its parts are obtainable from any hobby electronics store. The cable is a straight through with 20 pin female sockets at each end.
The power requirements for the newer controller board are very versatile. It can take 7-15V AC or 12-24V DC and so long as it's rated 11VA or higher it will work well. Since the board has a bridge rectifier the plug polarity on a DC power supply will not matter. Note that the power requirements for older controller board are slightly different. I tried running the older controller using a DC supply. The outputs work but the inputs do not. The controller board comes up on ebay every now again. Otherwise there were still a dozen or so available from BrickLink (see section 5b below) last time I checked.
The control and the power circuitry on the controller board are optically isolated. It contains two digital inputs and six outputs (capable of being pulse width modulated) where each group of two outputs can be sacrificed for one bi-directional output. The board uses power transistors to do the switching which allows it to perform speed control of the motors. In contrast to many hobby controller boards and kits of the time which relied on relay technology.
Information on the setup of the Interface A can be found here :- https://docs.google.com/open?id=0B5PVarmqxaOnUW1PTkZ4YXFCQVk
I took the box apart and took a few snap shots of the board.
5a. LEGO parts - electronic.
With the release of these sets, new electronic parts were added to the LEGO brick family, the touch sensor switch and the optical sensor with its rotary encoder wheel.
[08010dc01] - Electric, Light Brick 4.5V 2 x 2 with 3 Plug Holes, Trans-Clear Diffuser Lens
[6216m2] - Electric, 6216m2 - Motor 4.5V Type 2 for 2-prong connectors WITH middle pin
[x1167cx1] - Electric Touch Sensor Brick 3 x 2 4.5V Complete
[x1161cx1] - Electric Light Sensor Brick 3 x 2 4.5V Complete, Optosensor
[2958pb02] - Technic, Encoder Disk 3 x 3 with 4 Black Sections on One Side and 8 on Reverse Pattern
[766c375] - Electric, Wire 12V / 4.5V with two Variable Color 2-prong connectors, 375 Studs Long (Tip color can be OldGray/Light Gray, Blue, Yellow, Black or Red)
[766c14] - Electric, Wire 12V / 4.5V with two 2-prong connectors, 11 Studs Long
[766c96] - Electric, Wire 12V / 4.5V with two 2-prong connectors, 96 Studs Long
Things to be careful of when looking at the LEGO set part lists on websites such as ToysPeriod. I think most of it is correct but so far I have come across some parts that are missing or incorrect in colour or incorrect in part number or have ambiguous part numbers. I will note the discrepancies that I find.
Part "[6216m] - Electric Technic Motor 4.5V" is ambiguous. It could mean "[6216m1] - Motor 4.5V Type 1 for 2-prong connectors WITHOUT middle pin" or "[6216m2] - Motor 4.5V Type 2 for 2-prong connectors WITH middle pin". The wire that comes with the kits is 2-prong with the extra plastic middle pin so the type 2 motor is required. If you have some of the old 2-prong wire without the middle pin then you can use either motor.
The light brick "[08010cc01] - Electric, Light Brick 4.5V 2 x 2 with 2 Plug Holes, Trans-Clear Smooth Lens" is listed as belonging to set  but I don't think that is correct. I used "[08010dc01] - Electric, Light Brick 4.5V 2 x 2 with 3 Plug Holes, Trans-Clear Diffuser Lens" which contains the middle hole and matches the wire plugs that I have.
5b. LEGO parts - non electronic.
The best place to get LEGO parts is to raid the kid's Technic sets. If that fails, then head straight over to BrickLink https://www.bricklink.com/. Do not pass go and do not collect 200 dollars. BrickLink is a community of LEGO enthusiasts and has the biggest LEGO trading market that I have come across. From over two thousand possible vendors it has all the LEGO parts needed to create the Technic Control sets. I'll still look at other sites such as BrickOwl https://www.brickowl.com/ and ebay https://www.ebay.com but I'll use BrickLink as a reference point to see if I can get a bargain. The issue with using the BrickLink marketplace is that it is very cumbersome to use. It's an interface you would expect straight from the 1990s and I can see how it would keep some people away. It is in the process of a redesign but the change over date has not been determined so I was not going to wait. It was well worth the effort in learning how to use the site.
My process of obtaining the set parts went like this :-
First of all I needed a parts list for each of the three sets and the most complete lists I could find were at ToysPeriod https://www.toysperiod.com/. I know now that the ones at BrickLink are more complete but not by much. Putting these lists into a spreadsheet allowed me to remove duplicates between the sets. I also removed the parts I already had and parts that I had suitable replacements for like the minifigures.
The next step was to generate a .bsx file. This file is a structured XML file that is used by several programs when transferring LEGO part lists. I used BrickStore https://www.brickforge.de/software/brickstore/ to generate the .bsx file of my required parts. I chose to set the condition column to "U" for used, otherwise the software that uses this list will only try and match bricks in new condition.
At this stage I could have used BrickLink to determine who had each of my required parts for the best price but each vendor has their own pricing list and each vendor only has a subset of the parts that I needed. What was needed was a way to trawl through the data and work out which parts could be purchased from which vendor at the most cost effective price. BrickLink does not provide this functionality but Brickficiency https://github.com/WindmillHelix/Brickficiency2 does just that. I loaded my .bsx file into Brickficiency and I let it do all the hard work. This software uses the latest vendor price lists from BrickLink (so long as you are web connected) to work out different scenarios based on some starting parameters. This program is not going to give you the correct answer first time around. It takes a while for the program to run (depends on the starting parameters) and it takes a bit of time to get the starting parameters right. My suggestion is to get a super computer to run this on if you can. The output gives you price lists including totals based on the number of selected vendors. The more vendors I selected the cheaper it was in parts but more expensive in postage costs. I factored in $10 to $15 postage per vendor which resulted in a sweet spot of five vendors.
Now that the list of vendors is determined you need to check the vendor information at BrickLink. Some of these vendors may not ship to your destination, some vendors may have a total buy price which exceeds your order price and some vendors may have lot prices which exceed your order price. If that is the case then you will need to add these vendors into what is called the Blacklist in Brickficiency's starting parameters and run the process again.
Once you have done this a few times and have not given up hope then you can go into loading the lists from Brickficiency into BrickLink. Creating a BrickLink WantedList for each list / order will make it easier later than only using the default WantedList. The loading into BrickLink process goes through a verification stage to make sure the part numbers are correct. I got stuck at this stage on a few items due to using the part lists from ToyPeriods. Even though it cost me some time I'm still grateful to those who have spent their time in compiling these lists and making them available. The second process is to create orders, one for each vendor. The process is tedious in itself because you have to match each item in your list to a lot number from the vendor. An item can have multiple lot numbers so you need to pick the best one. Sometimes the vendor has made a mistake and an item in the new condition lot is priced less than the old condition lot. Sweet, you pick the new condition lot. Other times you may find that the lot contains a description that the part is of poor quality or you wanted a quantity of two but you can only purchase the lot in quantities of ten. Also double check your order because the order may be missing parts if that vendor has sold the part in the time it took you to get this far. You may be able to massage your orders around a bit to get around these issues or worst case, which happened to me, is you may have to go back and rerun Brickficiency. These last few steps took me about two weeks, including learning how to use both systems, before I was ready to place an order.
Once the orders were placed it didn't take the vendors long to dispatch the orders and it wasn't long before I received them. I must tell you though that getting used LEGO parts was like getting a box of chocolates, you never knew what you were going to get inside, and it so happened that I did get some chocolate. There was some brown stuff stuck in one of the parts. I can think of some other brown things it could have been so I'm just going to stick with chocolate. Most of the vendors were spot on and most of the used parts were as good as new however one part was broken, a few were past their usable life, some were missing (vendor replaced with different colour or similar parts). Also one of the vendors was a heavy smoker. Out of a thousand parts and only having these few issues I thought was fantastic. At this stage I realised I was missing a few parts due to the initial incomplete list so I had to put in an extra order anyway which gave me a chance to reorder the problem parts. I washed all the used parts and they came up great.
Parts to watch
" - Technic Pin with Friction Ridges and Slots" should be changed to "- Technic Pin with Friction Ridges and Slots"
"[367a] - Baseplate 24 x 24" was missing
" - Technic Gear Rack 1 x 4" should be OldGray/Light Gray and not Black (if you are particular about using the original set colours)
In terms of building the LEGO contraptions, I was creating freestyle contraptions until I was able to obtain the set's building cards.
 Building cards for set [9700-1] https://docs.google.com/open?id=0B5PVarmqxaOneUhJQ1BOT2hCVXc
Set 9700 Activity Card 1 - General
Set 9700 Activity Card 2 - Traffic Light
Set 9700 Activity Card 3 - Car
Set 9700 Activity Card 4 - Car Park Gate
Set 9700 Activity Card 5 - Conveyor
Set 9700 Activity Card 6 - Merry-go-round
Set 9700 Activity Card 7 - Washing Machine
Set 9700 Activity Card 8 - Turtle
Set 9700 User Instructions
 Building cards for set [1090-1] https://docs.google.com/open?id=0B5PVarmqxaOnZ0M3dE8wY1lBdGM
Set 1090 Activity Card - Parts Tray Organiser
Set 1090 Activity Card A - Ferris Wheel
Set 1090 Activity Card B&C - Automatic door, Washing machine
Set 1090 Activity Card D - Conveyor Belt
Set 1090 Activity Card E - Robot Arm
Set 1090 & 1092 User Instructions
 Building cards for set [1092-1] https://docs.google.com/open?id=0B5PVarmqxaOnWHZRc3dLMDRHSUU
Set 1092 Activity Card - Parts Tray Organiser
Set 1092 Activity Card A - Plotter
Set 1092 Activity Card B, C&D - Traffic Sign, Scale & Metrics
Set 1092 Activity Card E - Crane
Set 1090 & 1092 User Instructions
 Technic Control I Resource Guide https://docs.google.com/open?id=0B5PVarmqxaOnT0ZfQUhpVW84SDA
 ICC for IBM/Apple Computers (ICC stands for "Ideas for Communication and Control")
There are websites out there containing LEGO building instructions for sets. Great for getting freestyle creation ideas.
Here is one of my custom builds that I am working on. A single octave keyboard transmits keystrokes by multiplexing the signals through the LEGO controller and the TC Lego program plays the appropriate notes on the Apple II computer. You can see from the photos that not everything has to be a LEGO part. If you can't get the right parts then you can usually substitute by using alternate products.
Other robotic type retro LEGO builds can be found here:-
1. The robot book by Richard Pawson https://docs.google.com/open?id=0B5PVarmqxaOnSE1kT2MzLWZtSkU
Can be downloaded from here https://www.worldofspectrum.org/infoseekid.cgi?id=2000479
3. Atari Robokit http://www.robokit.info/index.html
4. [1038-1] ERBIE the Robo-Car https://docs.google.com/open?id=0B5PVarmqxaOnSl96OHozWDFIZ28
- .bsx files: https://docs.google.com/open?id=0B5PVarmqxaOnc0RRYUZoSHNkUDA (Not sure if totally correct. I fixed up the items I found to be inconsistent with the info I had. Will have a better idea when I get all the instructions.)
Update: 15th November 2015. Dutch Version.
Update: 12th April 2021. English (translated) Version.
- Commodore 64 LEGO Lines software and interface 9765 cable schematic: https://docs.google.com/file/d/1iG5Q-eqzdHpIF_17B-rk-CvI9aHHIZjo.
- Update: 30th May 2016.
- Here are a few more ports of the commercial software for other computer platforms. I don't have the hardware to test these on so all I can say is "Good Luck".
- BBC Micro version of LEGO Lines can be found here: https://stardot.org.uk/forums/viewtopic.php?t=9626.
- IBM-PC version of LEGO TC Logo and the Setup Guide: https://docs.google.com/open?id=0B5PVarmqxaOnVkZ2bGJybVhwSVk.
I find myself in a position where not only do I have some great sets to play with but I really enjoyed the challenge of putting it all together. It took me back on a nostalgic trip in several different ways. I was able to relive my LEGO days and also experience the time when not every consumer product is handed to you on a platter. Sometimes to get the things you wanted, you needed to work the system out, put bits together or even build it yourself. The road was not always easy but the journey was just as enjoyable as the end result. That is what I love about retro computing.
Enjoy and have fun.
Thank-you very much to everyone who helped out. You have helped in making this a great resource.