Caribeno Posted October 27, 2019 Share Posted October 27, 2019 (edited) Hi! A few weeks ago, I bought an Atari 800. Of course I wanted to open it to clean it and inspect it, so I was doing that a few minutes ago. While disassembling it, I found some strange ribbon cables in the expansion slots area: As far as I can tell, this computer has not been opened before, because still had the "Void If Removed" stickers in place, and a blob of silicone protecting a screw (of course, they could have been replaced after opening, but I doubt it). I looked for information about what are those cables, but haven't found anything. Here is a look on the side; the cables leaving the expansion area: As far as I can tell, the green-yellow-orange-red-brown cable connects to the 74LS42N chip, via a little board in between the motherboard and the chip; I tried to take some pictures, but the space is really small (and I did not want to remove the plastic casing for the cartridges and the expansion boards): (although blurry, the second picture better shows the 74LS52N on its board, and the cables connected to it). The purple-grey-white-black cable is connected to some pins of the left cartridge. Any ideas on what are these cables for? This is a newer 800, so the area for the expansion slots is not easily accessible (the door has screws, not the plastic levers to open it). Thanks! Andres. P.S.: While I was assembling the computer back, I realized that this one has to have been opened before, because the RF cable has been removed. Edited October 27, 2019 by Caribeno Clarification about computer being opened before. Quote Link to comment Share on other sites More sharing options...
AtariGeezer Posted October 27, 2019 Share Posted October 27, 2019 Incognito used to have a home there... Quote Link to comment Share on other sites More sharing options...
Caribeno Posted October 27, 2019 Author Share Posted October 27, 2019 18 minutes ago, AtariGeezer said: Incognito used to have a home there... I'm not super familiar with that board, but I was just looking at Lotharek's instructions on how to install it... The motherboard needs some jumper cables that are not present in this computer, and the 74LS42N is completely removed, and replaced with the ribbon cable, in Incognito. So I'm not sure... Are there different versions of Incognito, and maybe this one had a primitive one? Quote Link to comment Share on other sites More sharing options...
RodLightning Posted October 27, 2019 Share Posted October 27, 2019 (edited) 27 minutes ago, AtariGeezer said: Incognito used to have a home there... I guess everyone doesn't keep their spare chassis. Someone perhaps found a better 800 for their Incognito board? The mind boggles. Time to find some ram boards and see if the computer still works! Yes, there are a few chnges which must be reversed before putting standard Atari ram boards back in to test it. Edited October 27, 2019 by RodLightning Quote Link to comment Share on other sites More sharing options...
Caribeno Posted October 27, 2019 Author Share Posted October 27, 2019 8 minutes ago, RodLightning said: I guess everyone doesn't keep their spare chassis. Someone perhaps found a better 800 for their Incognito board? The mind boggles. Time to find some ram boards and see if the computer still works! Yes, there are a few chnges which must be reversed before putting standard Atari ram boards back in to test it. Ah! The computer came with ram boards, and it does work. Quote Link to comment Share on other sites More sharing options...
RodLightning Posted October 27, 2019 Share Posted October 27, 2019 (edited) Did the previous owner replace the 74LS42 chip or missing? Also forgot to mention you will need an original Atari OS board to go along with at least one 16k ram board to get it behaving as a stock machine. I'm wondering if something else is wrong with this 800 that it lost its Incognito board... Edit: Just read last post.. Great News! So you got the parts with it to downgrade. Good deal. Edited October 27, 2019 by RodLightning Quote Link to comment Share on other sites More sharing options...
Caribeno Posted October 27, 2019 Author Share Posted October 27, 2019 2 minutes ago, RodLightning said: Did the previous owner replace the 74LS42 chip or missing? Also forgot to mention you will need an original Atari OS board to go along with at least one 16k ram board to get it behaving as a stock machine. I'm wondering if something else is wrong with this 800 that it lost its Incognito board... Edit: Just read last post.. Great News! So you got the parts with it to downgrade. Good deal. But that's the thing with the 74LS42: it is there. So, is there a version of Incognito that, like in this computer, has a little board connected to the slot of the 74LS42, and the cables are connected to that board, and on top of it, the 74LS42? Quote Link to comment Share on other sites More sharing options...
RodLightning Posted October 27, 2019 Share Posted October 27, 2019 The 74LS42 function is replaced by the incognito board. The one I have here just has a ribbon header which plugs directly into the empty chip socket where the 74LS42 chip was. It's possible yours had an earlier prototype version of the board with slightly different design, but I am only guessing. Either way, it's a good thing you still have chip. If you managed to get your 800 to boot, then you must have gotten the original ROM board and one or more RAM boards back in their slots. A factory 800 has a "personality" ROM board in the wider slot in front. The three remaining slots should have 16kb memory boards in each for a total of 48kb. There may be a push button switch installed somewhere on the case as part of the incognito, which can be ignored if you keep it as-is. Quote Link to comment Share on other sites More sharing options...
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