dex

Sometimes the solution is SO EASY! Thank you both so much! Yes indeed it was BASIC I had to disable. Now it works perfect and right now I'm enjoying some demos after I've played Montezuma's Revenge and River Raid.

I'm some kind of newbie so please be patient I will try to do my best to provide as many informations as possible to solbe this problem. It was a long time ago (about 31 years, I was 5 years old ) I owned an Atari like this. I've got an Atari 800XE a longer time ago, it has a 130XE mainboard inside with 64 KB of memory. As I bought him some memory chips and the CPU were broken, it showed only a red screen (I've written a post here some months ago) and the drive was also broken. Meanwhile I've put new memory chips and a new CPU in the Atari on sockets and I have bought the Ultimate 1MB expansion and built it in. The drive is still broken but I've found a project called "SDrive-MAX", based on the Arduino UNO R3. So I've bought all needed parts and built the drive replacement. Now everything seems to work so far. But there are a lot of games I can't load (black screen after a short loading or just the READY prompt). River Raid for example shows a "k" in the top left corner while loading, than it stops loading and I see the READY prompt - that's all. Or the game loads but there are strange graphic errors (please have a look on my attachments: "Montezuma's Revenge", an ATR-file from the Holmes archive). I know this is a general question but I really don't know where to start. Maybe we concentrate on "Montezuma's Revenge" first if this is too general? What's wrong with it? I have tried to disable the extra memory of the Ultimate 1MB and I have also tried the other two versions from the Holmes archive: [cht] and [crt]. The [cht]-Version tells me I have to press START but I can press the START key as often as I like but nothing happens. The [crt] version loads only into a black screen and than it stops. I think I'm too stupid to load a game and even to find an answer for my question with Google. Or is there maybe something still broken? Do I have to put some new capacitors in? Are the ATR-files broken? Could this be a problem with the drive replacement "SDrive-MAX": http://www.kbrnet.de/projekte/sdrive-max/index.html(sorry, the page is only in German)? This really drives me crazy!

No almost a month later I'm back. Meantime I ordered a "new" Freddie but replaced the existing one in my 800XE but this didn't help. So I've checked again every chips temperature and the CPU (CO14806) seemd to be strange: only the half of the chip was warm. So I have desoldered the chip carefully and soldered a socket. Yesterday I got a new CO14806 and put it in and what can I say? It works! Thank you all for the hints and help! Today it is for me like christmas! Now I have to get a drive to see if this works and then I want to build a DIY SD card drive. I found some tutorials based on the Arduino Uno.

Thank you both for the hints! OK, this seems to get a longer process. I'll check eBay tomorrow to see what I can get, now I'm too tired. I have some 40 pin sockets and also some 74LS74 chips left. This is what I can do/test while waiting for the other stuff. Unfortunately I'm not absolutely sure if the memory chips are 100 % OK. I bought these chips on eBay, they have been offered as "new old stock" there but I looked today once again on the eBay page and the seller has not mentioned wether they have been tested or not. I'm waiting for another set of OKI chips I have ordered in Bulgaria, I hope to get them in the upcoming week. These chips has been sold as "tested". And I will get an Atari 130XE hopefully this week, too, but I don't know anything about its condition so far. The pins of the RAM chips are all OK, I tried also to press them with a little bit more pressure in their sockets but they didn't move.

Unfortunately no. Do I have to get exactly one with the same part number or are there any alternatives?

This would be too easy if ... . ​ Nope! Unfortunately the screen is still red.

Hello everybody, here I am again. Thank you all for the additional hints! The Sys-Check-Expansion looks very good! I have to search for an option to buy it somewhere. I think this thread can help me probably. I have received the sockets and the first memory chips and replaced them already. I have replaced them all and not only the hot ones just to "feel clean". The board is really very sensitive, I've never soldered something like this and just broke a land but repaired it than. After the sockets were soldered on the board I've double checked the connections beetween the sockets with a multimeter. There seems to be everything OK so far and the chips are not getting hot anymore, only just a little bit warm after some minutes the Atari is turned on. But the Problem is: The screen is still red! I have checked the other chips after some minutes and the warmest chip is the CO14806-12 but it is not getting really hot. It's getting only hotter after several seconds with my finger on it. I'm not sure if this is a problem or not. All other chips are getting only warm, except all the small ICs, the CO14795-12, the CO12294B-01 and the only chip which was on a socket: CO61991-01 – these chips are staying cold. I have removed the CO61991-01 from its socket as you can see on the photo attached to this post. The socket looks like somebody has already removed this chip at least once before. And as you can see there is a bent pin. I think this is not what this pin should look like. Am I right or does this make any sense? Should I try it again after fixing this pin?

Wow thank you very much! I have ordered now some sockets such as 8x the MB8264A chips and 8x M3764 chips, just in case one of them won't work or to have some in case of a damage. Now I got it with the U1MB memory expansion. I missunterstood this the first time. I think I will try to do it myself. Not because this would cost something but I really like to solder. I have a couple of Amiga computers where I have replaced capacitors and made some small DIY electronic projects for. I think I'm not very good but I love to sit down after work, turn the radio or some music on and do some solder work. This is some kind of relaxing for me. I hope this will fix the problem so I can play some of the good old games like Panther, Montezuma's Revange, River Raid, Boulder Dash, Moon Lander, ... . Emulation is nice but real hardware is not replaceable in my opinion. I will post here again to tell you if I've made it or not.

Hello again! Thank you all for your replies. And I'm happy that my English is not too bad. @Level42: I'm from Poland but I'm living since 1991 (when I was 7) in Germany. First I would like to fix the problem with the red screen (if it's possible) and than I will think about upgrading the Atari. I've already looked on Lotharek.pl, there are many fantastic expansions! I've already bought there an expansion for one of my Amiga computers. And ff I can get enough memory chips I would like not only to fix the red screen problem but also upgrade my 800XL up to 128 KByte RAM of course. My only problem now is what kind of memory chips I can use and where can I get them. I would prefer to get them somewhere in Europe so I don't have to wait too long but I don't mind to order them else where. I've searched in this forum and googled through the internet and as I can see there are often chips on XE boards with slower memory chips than mine. I've got some with 120 ns (?) timing but I have seen photos with slower chips on the board (150 ns and 200 ns but also faster chips with 100 ns). Am I wrong when I think it doesn't matter which timing they have? And what kind of chips can I use? Are there any alternatives or do I have to use Micron Technology MT4246 chips? After searching on the internet I have found some other 64k DRAM chips with the same pinout as the MT4246. Can I use them, too? I've found this page: http://www.amiga-stuff.com/hardware/64kx1-dram.htmland checked some of the data sheets.

Hello everybody I'm new in this forums. I've registered some months ago as I've received the Harmony Cartdrige for my Atari 2600 to say thank you but that was all so far. I hope my English is not too bad I will try to do my best you can understand me. Unfortunately I'm not a native English speaker. A week ago I got an Atari 800XE without anything – no power supply, no cables, no drive. It was sold as "untested". Well I'm not sure if this is true because I've opened it and found some human hair inside. But that's OK, I expected that. Unfortunately – after buying a power supply and connecting the Atari to my TV – it's showing only a red screen. I asked Google what kind of problem this could be and it told me I'm an idiot buying this stuff as "untested" and believing it could work. A red screen seems to be a problem with some components inside (ICs/chips). Anyway, it's the first time after round about 30 years I own a machine like this again. In the past my brother and me we got an Atari 65XE from our parents – I was 5 years old. Or let me explain this another way: I really don't have a clue what to do now! The case and the keyboard are looking pretty good. So I thought the board should be untouched but after I opened the case and removed the metall shell I've found two places on the board looking a little bit strange to me. The photo with the blue and the yellow cable soldered to the ICs looks to me like a DIY solution for I don't know what. The other photo shows three resistors soldered to U34. This looks pretty ugly. Am I right or is this just a usual and untouched board? I've also turned the Atari on for about 10 minutes and checked the temperature of the chips with my finger tips. Yes I know, this is not very professional. All chips seem to be cold or warm except two memory chips (the second and the third from the bottom), they are getting f...really hot! There is another chip I don't really know if its temperature is OK. It's the one on the top near the expansion port "CO14806-12". Is this the CPU? Its getting hot when I put my finger on the left side of the chip after about two or three seconds but I would say the IC is not all the time hot and it's not getting really hot when I touch it on the right side. I tried also to make photo of the board back but I'll do this better tomorrow in the day light. There are too many reflections and so it looks terrible. The five pins of the RF modulator look like somebody tried to solder there something for a reason with too much heat. I hope I can take a photo of this tomorrow. If you need more informations or photos, please let me know. What I would now like to know from you is whether there is a chance to rescue the Atari or not? And if there is a chance what should I replace? Only the memory or even more chips? What about the capacitors? I think these capacitors shouldn't leak and destroy anything but maybe they are too old and could also cause problems? And just because I'm curious: What is the IC at the bottom left "CO61991-01" for? Google tells me this is "Freddie". But what is this chip for and why is this the only one which is on a socket?

I got my Harmony Cardtrige SD today and I just want to say: THANK YOU! It's really awesome and very easy to use! What a great work! You made me happy, thank you so much! The whole shipping process took only 5 days to Germany to the customs in Frankfurt and additional 3 days to me.