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Upgrading and modding the Atari 800 too an 800A (Advanced)

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 Disclaimer: This is not meant to be a how-to tutorial or a step-by-step guide. This is merely photos of my upgrades with some description and explanation. But feel free to ask any questions about any aspect of it.


This is my blog on all the upgrades, modifications and hacks that have turned a standard 800 into a machine that is still the original vision of Jay Miner's Colleen 800 at heart, and still fully compatible, but includes advancements and upgrades that Atari never envisioned. At it's core, my new 800AI includes an Incognito board which expands it's capabilities to not only that of an XL/XE machine with 64K main memory, but far, far more including; 1MB extended ram multiple OS's and hi-speed SIO, bult-in BASIC and SpartaDOS X, as well as room for other cartridges from any point in the 8-bit era, a CF card virtual HDD and PBI capabilities and much more.


Beyond the Incognito the 800 has been upgraded to Stereo sound first, with a DIY dual-POKEY, then replaced with multiple POKEY cores and Covox DSP with the Pokeymax Quad + Covox board. Also a Sophia 2 GTIA replacement and upgrade board (adding more graphic modes) and modern video out with either DVI/HDMI or RGB or VGA. Also a dual PIA board for double the controller output jacks allowing many more exteral devices to be connected and controlled by the 800. An extra SIO jack, Stereo out headphone jack, S-video, composite and mono audio jacks installed for direct connect of standard cables and no more mess of various cables hanging out the side of the 800. The original SIO port is left open for easy temporary connection of peripherals or dead-end SIO peripherals. Fujinet will become a part of the Atari 800AI system as well, and will plug into the side SIO port. Also, a real PBI edge-connector port has been installed on the rear left side of the 800, and is now capable of using any exterior PBI devices, the first of which is a Turbo Freezer.


With all these advanced upgrades I felt that just '800" was not good enough anymore, and there needs to be an addition to the name for it's advanced features just like the XL/XE (eXtended Line/eXtended line Enhanced). But another X and some other letter on the end is a bit unimaginative. So I came up with AI for advanced and Incognito. But it also can mean advanced intelligence so it's sort of a dual-meaning. Or even triple meaning as "A" is first in the name ATARI and "I" last, and it's the first Atari computer with probably the last truly system changing upgrade it will ever see in the Incognito, so it's also sort of like first and last or Alpha and Omega. I was actually going to call it the 800A(Omega symbol here) But I couldn't find the right size of an Omega symbol decal to put after the "A." See picture below of the small silver decals of "A" and "I" that are in the original Atari font I got from a decal set I bought online with metallic Fuji Symbol and "Atari" underneath (all separate decals that get pressed on together before removing the backing. I used just the Fuji for something else and had the Atari letters left over so got the idea to use them on the 800 since they were very small so it would be much more subdued than the XL and XE lines with letters the same size as the rest which I felt would look to gaudy on the 800 so I went with small and conservative like Atari did with lettering on the STfm and STe machines when they were added to the new model names signifying what was new and different about them.







The upgrades, mods and fixes


The first upgrades I did are 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 an 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.







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After the successful incognito and DIY dual POKEY installation, Plans have been changed to a Pokeymax Quad+covox audio upgrade. Quite a leap from just stereo, but I want the best for this upgrade project. 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 also installed 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. 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 was 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.


 I then 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.


I used 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.


(Pictures are not in the order of the descriptions above)







    The next modification was 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.

Next I 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.


(pictures are not in order of descriptions above)







      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.


     Continuing my 800 upgrades and mods, I made a true PBI edge-connector port for the 800. It was already upgraded with full PBI capabilities from the Incognito, but there is a 50-pin (SCSI?) style connector on it that is the gateway to PBI devices being connected. As with my DIY PBI upgrade on my 1200XL, I created and actual PBI edge-connector port on the rear of the 800. With the 1200XL, I salvaged parts from a 600XL for the mod/upgrade. With the 800 I was able to use the a XE ECI-to-PBI adapter that I don't need for an XE and never will, that came with my Turbo Freezer 2011. I still have to get the connector and 50-wire ribbon cable to connect to the Incognito and create the physical buss. On the 1200XL I purchased a length of 50-wire rainbow ribbon cable for it, and of course had to make all connections directly to the IC's, instead of a connector to plug in.


I also made an enclosure for the Turbo Freezer's PBI board, with a connector on it for the actual Turbo Freezer housed in a cartridge case. I just used an old, small, project box that has been laying around for years, the board didn't quite fit, so it has "wings" out the side, but I think it still looks better than a bare board, and I'll paint it to match the 800.



The Sophia 2 board upgrade was the next and second to last upgrade (dual PIA IC's will be the final upgrade). Since it's a plug-in board I didn't bother taking pictures of the Sophia 2, though I did removed the original socket for the GTIA chip on the CPU board and installed a precision socket to lower it's profile so it can fit inside the shielding were the CPU board is hidden. After that, I had to cut an opening in the heavy metal shielding so the video cable from the board could "escape." I decided to place the Sophia board in between the Shielding and PSU board's heat sink vertically as there was few other choices with the modifications I've already made. I next cut out a spot on the back of the 800's upper case half to mount the Sophia 2 board. I again used E6000 adhesive to mount it as I did for the PBI and other audio/video upgrade boards. It's strong and will hold the upgrades in place without the need for screws and bolts and holes drilled, yet easily removable, if needed with a razor blade and peeling away excess. Later on, when the dual-PIA board is installed, another 2-4 controller ports will be mounted next to the DVI output.







This bog is not yet completed as I still have to install another multi-part upgrade/modification to my 800 will be dual PIA board to be used for additional controller ports. This upgrade and mod is there are still more than two controller ports when I'm using the 800 Incognito in XL/XE modes and ports 3 and 4 are used for Port B memory banking. I also will be using more than 4 ports, even in 800 mode on the Incognito along with a half-dozen AtariLab  Interface devices and DIY clones of the AtariLab Interfaces for help in a future project of building a robot, with an Atari 800 brain, that will eventually be autonomous, but while in the research. experimentation and prototype building stage it will be controlled through the 8 controller ports. AtariLab Interfaces are basically break-out-boxes that make it easier as I can use standard RCA cords between the Atari and all the sensors for the robot to know where it is and avoid obstacles or interact and also Ardruino boards that will control arms and trax of the Robot as well. The intention being a 100% 8-bit robot


Some other changes or previous upgrades and fixes to the 800 include: luma output resister change mod (for improving picture clarity as luma is over-boosted for today's standards), The RF has been disconnected to avoid interference from signal bleed on S-video and composite, the channel switch has been re-purposed for a mono/Quad stereo switch, a wire modification to the right cartridge port (and trace cut on the left port) so that a needed signal is available so that The!Cart and MyIDE II will work in the left cartridge slot on the 800 and internal RGB-LED lighting and keyboard lighting. I also have a Fujinet on the way for this 800 too.


Another possible upgrade would be a MIDI board. The problem with more upgrades is locations to mount them internally in the 800. There is still plenty of room on the left side of the 800,, but the issue is that anything mounted internally there would either need port extension modifications so I can mount them on the back by the DVI and 2nd PIA controller ports. Obviously there is the left side of the 800 to mount jacks, but I just went through a lot of trouble getting rid of side ports with cables in the way, and keeping my new ports hidden and "Incognito" and I don't want to start populating the left side ruining all that now.


UPDATE 8-14-21


I now have the dual-PIA installed and will install a MIDI board soon. I will add further pictures and comments soon. I have decided to go in a different direction with mounting the ports for the dual-PIA's 4 new controller ports as well as the MIDI ports. I am running ribbon cable through the 800's bottom venting on the left side (the side where the PBI port is if looking at the 800 from the front). The idea is that since my 800's PBI port sits much higher up than PBI and ECI ports on the XL and XE lines, so that means that PBI devices designed for those computers just hang on my 800's PBI port. So since a stand is needed anyway, and I need a place to mount controller and MIDI ports I came up with a solution.


So my solution to both the PBI height issue and I need a place to mount the ports for the Dual-PIA and MIDI ports, but don't want to hack the side of my 800's case, and there is no room to fit them on the back as either shielding or PSU heat sinks are in the way on the back except for above the PBI. But that area I can't use either because the Turbo Freezer will plug in there and since it's a board with a connector and the actual Turbo Freezer part is in a cartridge case sticking up vertically in the back, it would be in the way of any ports mounted there. So my solution is to 3D print a case that is also a PBI stand that I will design that has the Turbo Freezer board on top, and enough room in the bottom to mount the new controller and MIDI ports. and the case will also have an open stand area for the pass-thru PBI edge connector for additional devices to sit. Ribbon cables will come out the venting and connect to the Turbo Freezer directly under the PBI port slot and be hidden away from view. It will all easily plug in and unplug from the PBI Turbo Freezer stand/case. I will design this stand and case to match the lines of the 800 case so that it looks good aesthetically too.


I will wait until it is all completed before I start adding more pictures and comments to the blog beyond this update.





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