This blog is an on-going blog of all the electronic hardware hacking, modifications and upgrades. Mostly Atari, for now only Atari.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.
.AtariLab Interface modding and hacking
But the AtariLab Interface was made for so much more, and the starter set explains, with minor examples, of musing 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.
This section of the blog is all about my adventures in modding my Atari 800. So far I have installed an Incognito board and a dual-Pokey upgrade (less the actual audio output). And I did some repairs on the keyboard and modified a shift key to be more balanced and sturdy by inserting and extra plunger and spring in an empty key spot below it. Hopefully this will solve a design problem that causes the plunger to crack and stop the new plunger from cracking in the outside corners that make the shift key bind.
Atari 800 hacking, modding, upgrading
As I've mentioned elswhere before, all current and future upgrades and mods are from now on going to be installed by me using Dupont connectors as seen in the pictures below, and eventually I intend to retro-fit all my upgrades in this way, for easy removal and installation for trouble shooting.
Below are pictures of these installations. I had her back together already, but the keyboard didn't work, and after rechecking my dual Pokey installation, have come to the conclusion that I used a bad 74LS14 IC, and have now replaced it with a new 74HC14 and am about to power it up, after I finish this blog segment, and see if the keyboard works. The Incognito worked fine.
Well, after months of postponing my 800 upgrades and mods, due to an unknown issue that turned out to be the keyboard, I'm back at it. The keyboard is yet to be fixed or replaced, but the project is moving forward without it for the time being.
So, after the successful incognito installation, the stereo upgrade was and is the next step, though the original plans for a DIY dual-Pokey have been changed to a Pokeymax Quad+covox audio upgrade. Quite a leap from just stereo, but I want the best.
The Pokeymax is plugged in the socket and is currently working as a standard Pokey until I get a couple of wires connected to the CPU and audio output with a simple pre-amp circuit to bring it up to line-level audio. I am also installing a second SIO port and due to the placement of these new I/O ports I am combining the Pokeymax audio out with the SIO out on the same circuit board.
So the first step on the new board was to attach the SIO connector (one of half a dozen new 3D printed ones I bought from The Brewing Academy) to the board and a cable to the new SIO port that is connected at the other end to the original SIO port, continuing the SIO daisy-chain internally in the 800. I went with shielded VGA cabling since I have plenty on hand and it's the best thing to use to ensure no interference in close proximity to the motherboard. The cable is directly soldered to the new SIO connector and it's board, but I installed Dupont connectors to the SIO port on the 800's PSU board for easy removal and installation in the future. I fanned out the pins on the back of the SIO so I had room to plug in the Dupont connectors with the capacitor for the PSU in the way.
The next step will be to install a headphone jack stereo audio out to the new circuit board and attach a wire harness to the Pokeymax that will run to the new board.
Continuing the upgrades, I have now attached the wire harness to the Pokeymax, with three wires going to the CPU on the CPU board and three wires going to the SIO/Stereo out board. I used a headphone jack style stereo audio out so it would fit on the board with the SIO port, and both will fit nicely where I make cut-outs for them on the underside of the case, leading out the back left recessed area of the 800 case underside. Again I use DuPont connectors at the audio out for easy separation from the motherboard and CPU board. The only thing left for the Pokeymax upgrade is to make a spot for the audio out wires to go through the heavy shielding. I suppose I'll have to drill a hole through the shielding near the Pokeymax chip. And I just remembered I need to connect the headphone jack's ground to ground on the SIO connector which is connected to ground through the cable to the PSU to ensure proper grounding.
Next will be S-video, composite and mono audio out board directly opposite the 2nd SIO/audio out board, it will be hidden underneath the PSU board and connected to the original monitor port in close proximity. Once that board is done, then I will cut out spots for all the new I/O connectors in the 800's bottom case, then mount the boards and I/O connectors.
As promised in the last paragraph, I've made a DIY S-video/Composite/mono audio out board. Like the second SIO, these are just direct lines from the nearby monitor jack. As per usual now, at least one end is attached with Dupont Connectors so that all upgrades and boards can be easily separated if need be. I had left/right audio jacks on hand, so the red one has been re-purposed for composite video (I only want this for NTSC high-res games for artifact colors).
The mono audio out is white. Instead of attaching a switch to one of the Pokeymax lines to change between mono and Quad-stereo out, I left it so Quad-stereo is always on as I will use the mono out for programs that don't use stereo. And of course, the main reason for the DIY mod board, is a real S-video jack. The S-video on both my Atari's gets fed through either video-to-VGA or video-to-HDMI outs and they don't make the adapters with separate chroma/luma lines. But my 1200XL uses a break-out-box for video which does have separate chroma/luma for when I get my CBM 1084S monitor repaired which does have these inputs. The 800 will always be connected to a converter.
But now, except for the power jack, I no longer have to have cables coming out the side of my 800 getting in my way on the desktop. All other I/O will now be discretely placed in the recesses on the underside of the 800 with all cables hidden and running out the back like XL/XE machines. Though I'm out of space there now, since the 800's motherboard fills the rest of the bottom case, my PBI and extra controller ports will have to be mounted to the rear left side of the 800 coming directly out of the back. So all that is left for these upgrades and mods is to cut port holes in the 800's case and mount the boards.
Here are pictures of my two I/O boards mounted in the case. I used E6000 Industrial adhesive, which is like an epoxy, but remains slightly "rubbery," and after curing for 24 hours the boards will be completely secure. This was my final solution for my PBI in my 1200XL how it's mounted and is holding the PBI in place tight, for over two years with PBI devices plugged and unplugged over that time. The second photo, left to right are my new S-video, mono audio and composite video jacks. The third picture, left to right, SIO port and Pokeymax stereo audio out via mini phono jack.
So what is left? Other upgrades/mods intended for the 800 are an internal Turbo Freezer (still waiting to arrive in the post) which will also serve as my PBI port out the back of the 800 using it's PBI pass-thru edge connector. Also Dual or possibly triple PIA board (waiting to arrive in the post) for the possibility of many more controller ports for my external projects. The final upgrade to the 800 will be a Sophia 2 board (waiting for it to be available). And, of course the keyboard will have to be repaired or replaced, but in the mean time, a TK-II PS/2 keyboard interface (waiting for it to arrive in the post) will be temporarily installed so I have a keyboard to use with the 800 until the original is back in place. Then I will call the modded 800 complete.
To be continued...