AtariLab Interface modding and hacking
The AtariLab Interface is a peripheral that plugs into the controller port(s) of the 400/800/XL/XE machines and as many can be used as you have controller ports for. Originally the Interface came in the 'AtariLab starter set' which was to be the main kit in a series of educational experiment software and hardware modules. The 'starter set' came with one Interface and tools and software cartridge for the first module, the temperature module. Do to poor sales and/or the video game crash of '83/84 which lead to the sale of Atari and the new agenda of Jack Tramiel only one other module for the series was ever released, the light module.
But the AtariLab Interface was made for so much more, and the starter set explains, with minor examples, of using the Interface for your own experimentation and projects. It's essentially a controller port break-out-box allowing for the easy connection and interfacing to the Atari computer through RCA jacks that use every line of the controller port(s) but for the trigger/fire button line. The Interface can be used as a prototype and experimentation device for anything one can dream up to interface with Atari computers (and any computer with Atari compatible controller ports really) and through it either control or communicate with external devices from the computer or vice-versa. I have no idea why they didn't include all 8 I/O lines (one line is ground) and instead decided to include two +5V outputs on the 8 Interface I/O lines and leave out fire/trigger input.
I was dissatisfied with two things about the AtariLab Interface. One, the missing fire/trigger button input line, and two, a power switch as the interface powers up with the computer or when plugged in if the computer is already on. A pet peeve of mine are devices that only power on and off by plugging them in, when a on/off switch is literally the simplest circuit one can build in electronics and is the basic circuit and basis of all computers. On/off, zero and one, open or closed. Computers are literally made from this simple circuit and would not exist as we know them without it. It's literally what makes up the internals of all I.C.'s and computers work based on which of them are on and off, high or low, one or zero. So why power switches aren't included in every electronic device made is beyond me. But, since it is such a simple and basic circuit, I add my own to devices without them, and the AtariLab Interface is one example.
So after investigating and researching the interface and it's circuit, I added power switches and fire input to the three Interfaces I own. The power switch I installed myself and created the circuit for it. The fire button I implemented trough one of the two +5V lines which are really both connected to the one +5V line of the controller port, and if I need more than one line, it's easy enough to use an RCA splitter to get two or more +5v lines back through the interface. I wanted to make sure that every single controller I/O line is available for me to use for my interfacing projects and experiments.
I have purchased two extra interfaces that are surplus, with no labels, separately from B&C Computervisions (MyAtari on eBay). So why do I want or need more than one? Because I may want I/O possibilities through more than just one port. For example, and the project that caused me to gain interest in the interfaces is the 'Arm your Atari' article from Analog magazine issues 44 and 45, summer 1986. It's a project for connecting a Radioshack Armitron robot arm to your Atari through the controller ports. The full project requires 3 of the 4 ports of an Atari 400/800 and originally requires the user to hack together connectors for the controller ports to interface with the robot arm. With the AtariLab Interface, this is not required and I can connect everything, at least in the research, development and prototyping stages. If needed, the final project can have it's own controller port plugs. I intend, now that I know the interfaces inside and out, to build my own DIY forth interface as I intend to make the 'Arm Your Atari' project merely a starting point that I will expand on, eventually building and interfacing an entire robot through the controller ports and I also foresee the possibility of needing even more I/O lines through controller ports, so I intend to add a second PIA I.C. to my 800 and even more controller ports for this long-term project and others.
So why interface with the Atari through the controller ports (aside from the initial project from Analog doing it that way)? Because the SIO, PBI and cartridge ports on my systems are already clogged with devices that I will need too, and clogging up the plumbing even more for such interfacing could cause traffic jams and interference, etc. with other devices connected to the system. A perfect example of this is the SDrive-Max device that connects through the SIO but will not work with other devices on the SIO unless another circuit is made to allow it to work. I don't want to have to worry about device and communication conflicts when I do my interfacing projects. Also because the PIA chip(s) is a wonderful little chip with all kinds of communication and I/O properties that are hardly ever used and free to use with my projects even with everything else being used.
The pictures below are of what I've modded on my interfaces, and also show how the first interfaces were totally screwed up and Atari had to manually rewire them by hand to make them work correctly, like the center interface, where the green wiring is all Atari's rewiring. Only the yellow, blue and red wires were added to the interfaces by me to create fire button input and power switches. The interfaces on either side are the extras I purchased, which are a later, correctly done revision of the Atari Interface. I scanned the original interface's labeling and printed and cut out two copies for my other devices. They are slightly blurry due to the power switch not allowing the device to lay flat while scanning it, but it's good enough for me, and still better than hand labeling it all myself.