Colleton Posted March 8, 2020 Share Posted March 8, 2020 (edited) Bought an NTSC 800 with a production date code of 949 this past week and received it on Thursday. Surprisingly, at least to me, it works very well. It has a CTIA chip and a 6502B CPU. I haven't checked to see if it has OS A or OS B yet, but I will once I have it re-assembled. It has 48K of RAM, with a 16K board and a 32K Axlon RAMCRAM board. I wonder if this one originally came with an 8K or a 16K board? Right now it's completely disassembled. So far I've only seen minor differences between this machine and late production machines. The biggest difference I can see and easily recognize is the keyboard cable and the associated connector on the motherboard. The cable is just a stiff wired ribbon cable with bare wires at the end and the motherboard connector is just a row of holes for the wires to poke into. The case is out in the back yard right now in a vain attempt to "light brighten" the darkened plastic. It will take weeks in the sun, and probably much warmer temps to work, so I'm not expecting much from this weekend. The keyboard keys are soaking in hot water right now, and I've blown out the keyboard assy itself. The side board was absolutely filthy and the large 4700uf caps are bulging. I've cleaned the board with alcohol and then deoxit and have ordered replacement caps for the side board and main board. Same cleaning for the main board. I swear I'm going to catch some deathly disease from cleaning the crud out of these old computers. If anyone has any questions, just ask. Edited March 8, 2020 by Colleton 7 Quote Link to comment Share on other sites More sharing options...
Colleton Posted March 8, 2020 Author Share Posted March 8, 2020 (edited) Oh, the two plastic poles that hold the cartridge door spring in place are broken off and long gone. I don't know what to do about that, it doesn't look like an easy fix. Edited March 8, 2020 by Colleton Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted March 8, 2020 Share Posted March 8, 2020 nice example! i read somewhere that retrobrighting with the peroxide method is damaging to the textures of 400 and 800 machines. This makes the natural light method preferable but as you say it takes longer and the changes are gradual. At least you have the before pics to compare it to. I have a 400 that has the same keyboard connector you described. It feels a bit brutal fitting it but it works fine. 1 Quote Link to comment Share on other sites More sharing options...
BillC Posted March 8, 2020 Share Posted March 8, 2020 1 hour ago, Colleton said: I wonder if this one originally came with an 8K or a 16K board? I never had a new 800, the first I got was already 25+ years old, but I think the early 800s originally came with 16K RAM while the early 400s came with only 8K. The 400 I received for Christmas 1980 came with only an 8K RAM board. 1 Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted March 8, 2020 Share Posted March 8, 2020 why does this say 400 on the serial label? The ram modules don't have metal cases either... this seems to be a frankenstein compilation. Ignoring the case for a moment, I would love to see pics of the boards and the CTIA. Quote Link to comment Share on other sites More sharing options...
Colleton Posted March 8, 2020 Author Share Posted March 8, 2020 2 minutes ago, kheller2 said: why does this say 400 on the serial label? The ram modules don't have metal cases either... Yeah, I have no idea why the label says 400. I'm sure the RAM module cases were removed by a previous owner, but who really knows? I'll see if I can take some pics. Quote Link to comment Share on other sites More sharing options...
xrbrevin Posted March 8, 2020 Share Posted March 8, 2020 i thought early modules were cased and later ones not but i might be mistaken... ? Quote Link to comment Share on other sites More sharing options...
jamm Posted March 8, 2020 Share Posted March 8, 2020 There are other examples of early 800's whose serial number label says 400. I think they're in the "Calling all 800's" thread? As xbrevin said, the keyboard connector sounds the same as that on the 400's. For what it's worth, I removed the yellowing from my 400 very successfully using the "V40" hair salon developer cream. I brushed it on the case and didn't wrap it in any sort of plastic wrap, though, to avoid uneven blotchiness. Let it sit for around 48 hours in a room with lots of indirect sunlight and it turned out perfectly. I don't understand how just putting these pastics in the sun helps, since that's much of how they got yellowed in the first place. Machines that have been sitting out near windows all their lives show the most yellowing from the sides with direct exposure to sunlight. Plus, I don't see that that method is any less likely to cause damage to the plastic than the other methods. Quote Link to comment Share on other sites More sharing options...
jamm Posted March 8, 2020 Share Posted March 8, 2020 10 minutes ago, Colleton said: Yeah, I have no idea why the label says 400. I'm sure the RAM module cases were removed by a previous owner, but who really knows? I'll see if I can take some pics. The original encased RAM card must've been replaced when the Axlon upgrade was installed. The odd stranger thing is that the OS board isn't encased. Quote Link to comment Share on other sites More sharing options...
Colleton Posted March 8, 2020 Author Share Posted March 8, 2020 (edited) Here are pics of the boards. Hope they show what you want to see. Edited March 8, 2020 by Colleton 2 Quote Link to comment Share on other sites More sharing options...
ClausB Posted March 8, 2020 Share Posted March 8, 2020 (edited) My 949 came with 8K RAM boards which were upgraded to 16K professionally two years later. Edited March 8, 2020 by ClausB 1 Quote Link to comment Share on other sites More sharing options...
adam242 Posted March 8, 2020 Share Posted March 8, 2020 That is indeed revision A ROM on the OS board, chips numbered CO12499A and CO14599A. And interestingly, the Atari math pack has been replaced with a Newell FastChip! The stories this 800 could tell.. 3 Quote Link to comment Share on other sites More sharing options...
Colleton Posted March 9, 2020 Author Share Posted March 9, 2020 2 hours ago, adam242 said: Newell FastChip Never heard of this. Interesting. Quote Link to comment Share on other sites More sharing options...
Colleton Posted March 9, 2020 Author Share Posted March 9, 2020 2 hours ago, ClausB said: My 949 came with 8K RAM boards which were upgraded to 16K professionally two years later. Good to know, thanks. I've already posted the info to the thread. Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted March 9, 2020 Share Posted March 9, 2020 Thankfully, I have had NO capacitor issues with my 800. Quote Link to comment Share on other sites More sharing options...
Colleton Posted March 9, 2020 Author Share Posted March 9, 2020 FWIW, I replaced all of the electrolytic caps this afternoon. Both the side board and the main board. Working like a champ. The keyboard cleaned up really nicely. The case is a work in progress, lol. Quote Link to comment Share on other sites More sharing options...
Kyle22 Posted March 9, 2020 Share Posted March 9, 2020 Good luck. I wish you the best. When you get it put back together, call my BBS. :) 2 Quote Link to comment Share on other sites More sharing options...
Faicuai Posted March 9, 2020 Share Posted March 9, 2020 13 minutes ago, Colleton said: FWIW, I replaced all of the electrolytic caps this afternoon. Both the side board and the main board. Working like a champ. The keyboard cleaned up really nicely. The case is a work in progress, lol. Overall, I would strongly suggest you re-considering a prolonged exposure under the sun... as plastics will invariably debilitate. Instead, 40% peroxide cream will do the job perfectly, provided that is applied and rinsed, periodically. It will seriously accelerate the work, minimize plastic fatigue / damage, and even protect the 800's distinctive surface luster. 2 Quote Link to comment Share on other sites More sharing options...
Colleton Posted March 9, 2020 Author Share Posted March 9, 2020 13 minutes ago, Faicuai said: Overall, I would strongly suggest you re-considering a prolonged exposure under the sun... as plastics will invariably debilitate. Instead, 40% peroxide cream will do the job perfectly, provided that is applied and rinsed, periodically. It will seriously accelerate the work, minimize plastic fatigue / damage, and even protect the 800's distinctive surface luster. Sunlight works very well, with no ill effects that I can see. It just takes a long time to work. I know peroxide will speed the process up. I used it on an ST case with a good result a few weeks ago. Maybe I'll try jamm's suggestion listed above. 2 Quote Link to comment Share on other sites More sharing options...
jamm Posted March 9, 2020 Share Posted March 9, 2020 55 minutes ago, Faicuai said: Overall, I would strongly suggest you re-considering a prolonged exposure under the sun... as plastics will invariably debilitate. Instead, 40% peroxide cream will do the job perfectly, provided that is applied and rinsed, periodically. It will seriously accelerate the work, minimize plastic fatigue / damage, and even protect the 800's distinctive surface luster. To be clear, the "V40" peroxide cream is actually 12% hydrogen peroxide. (this page has a good write up on the different labeling used for these products). Any higher concentration than that would be a bit dangerous. Personally, I'm less interested in getting it done quickly than in getting good results. Leaving anything out in direct sunlight seems like a bad idea, but then I live in the desert where such behavior usually doesn't end well. 1 Quote Link to comment Share on other sites More sharing options...
Sugarland Posted March 9, 2020 Share Posted March 9, 2020 Congrats on your pre 80's 800! The home computer revolution was barely starting and such a device was a mystery to %99+ of people. 2 Quote Link to comment Share on other sites More sharing options...
mimo Posted March 9, 2020 Share Posted March 9, 2020 I have retrobrighted several 400's and 810's. I ruined one 400 case when it bloomed.All the others were OK with no damage to the texture and good even colour. After having good success with lightbright I doubt that I will ever go back to using chemicals again though 1 Quote Link to comment Share on other sites More sharing options...
Colleton Posted March 10, 2020 Author Share Posted March 10, 2020 Well, I've been trying jamm's idea of painting the case parts with peroxide creme and leaving them to sit in a room with indirect sunlight for the past 2 days. ~9-10 hours each day. I wash them off in the evening and re-coat them in the mornings. I'd say it's working very well so far. The real darkness is gone, but the case is still slightly darker than the area that was (I'm assuming) covered by a sticker at one point. I'm including a pic, and you can also see it in the 1st pic in the OP. I think it will be very difficult to lighten the case to that point, but needs must. No rest for the wicked... Quote Link to comment Share on other sites More sharing options...
jamm Posted March 11, 2020 Share Posted March 11, 2020 I'm curious what the really yellowed area in the back parts of the case look like now. Can you post more pictures? Quote Link to comment Share on other sites More sharing options...
Colleton Posted March 11, 2020 Author Share Posted March 11, 2020 The bottom case back needs more work, but it is much better. I need to turn the back towards the window for a few days. What do you think? Quote Link to comment Share on other sites More sharing options...
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