KLund1 Posted May 6, 2016 Share Posted May 6, 2016 I have a couple 400's I want to upgrade to 48K. I know there are ways to change a 16K card to 48K. Are there kits out there for sales other than BestE? Those prices have really gone way up. Or are there simple instructions some where in here that easily show how to do the upgrade? Hopefully with some pictures. I have googled and have found multi page detailed guides to do it, but they had terms, parts, and details I did not understand. I have another 400 that I upgraded a few years ago with an Atari 400 48K Expansion Kit. I could use that as a template for the MB jumper wires perhaps. I also need a cart door spring. I can't find any at Home depot or Lowes that work or fit. 1 Quote Link to comment Share on other sites More sharing options...
Panther Posted May 6, 2016 Share Posted May 6, 2016 There are two versions of this mod that I found. There's one by Gary A. Crowell which appears to be compatible with the factory upgrade, as the changes to the 400 or the same, just four jumper wires, and the the mods to a 16K card. Then there's a version by Claus Buchholz which requires a bit more modding to the 400, but less changes to the RAM card. I went with the version by Claus and it worked well, though I'm sure the other version is fine too. Quote Link to comment Share on other sites More sharing options...
KLund1 Posted May 6, 2016 Author Share Posted May 6, 2016 Thanks, I could not find the Gary A. Crowell version. link? I had found the Claus Buchholz method, and it is just bit beyond my skills. I looked at this http://atariage.com/forums/topic/251346-48k-400/?hl=%2Bclaus+%2Bbuchholz that had some pictures. After reading the article's directions and looking at the pictures, I saw enough differences that I would most likely screw it up and kill the 400. The Ram card I think I could do. I would need some serious hand holding for the rest. Like the parts list shows 2 resistors , but I see three in those pictures. Or this quote "Finally, solder one of the 680 ohm resistors between pin A under the cartridge slot and the nearest ground connection" I would not know a ground connection from a washing machine. Then there is sourcing the parts. This is as close as I could come. http://www.ebay.com/itm/DRAM-64kx1-Dynamic-RAM-64k-x-1-200ns-HM4864P-3-MB8264-20-M5K4164NP-20-8-pieces-/251666089003?hash=item3a9877c42b:g:glkAAOxy-WxTA3Xp http://www.ebay.com/itm/2pk-74LS158-ICs-Multiplexer-/370675771208?hash=item564dff6748:m:m8GcrsrbyZKEmP70MVd8mzQ http://www.frys.com/search?storeNo=All+Products&search_type=regular&sqxts=1&cat=&query_string=74ls02 http://www.frys.com/product/5359038?site=sr:SEARCH:MAIN_RSLT_PG This is the closest resistor I could find at my work. I'm sure we have the right one, but I can't find it. Quote Link to comment Share on other sites More sharing options...
Panther Posted May 6, 2016 Share Posted May 6, 2016 Unfortunately, the scan I have isn't particularly clear, but here it is: http://www.atariverse.com/mods/400/Atari 400 48K Upgrade (Crowell).pdf As for the parts, forget Fried Electronics and eBay. Look at Mouser, Digi-Key, and Jameco. Quote Link to comment Share on other sites More sharing options...
KLund1 Posted May 7, 2016 Author Share Posted May 7, 2016 This looks just as complicated. I'll have to read them both more carefully with a 400 open so I can follow along on the hardware as I read the directions. I work a frys,and get the parts for near free, IF we carry them. Big IF. I know we do not have the 74LS158, or the drams ic's. Mouser, Digi-Key, and Jameco for those. But we should have the cap, and resistors, but I do not know enough about there descriptions to find the right ones. If you have a couple extra minutes, could you take a quick look, and send a link if you find the right ones? Thanks for all your help! Quote Link to comment Share on other sites More sharing options...
ClausB Posted May 7, 2016 Share Posted May 7, 2016 I'm available to help. Below is a link to the article which includes diagrams that show where "the nearest ground connection" is, and other details. Quote Link to comment Share on other sites More sharing options...
ClausB Posted May 7, 2016 Share Posted May 7, 2016 http://atariage.com/forums/topic/251346-48k-400/?do=findComment&comment=3488685 Quote Link to comment Share on other sites More sharing options...
Panther Posted May 7, 2016 Share Posted May 7, 2016 If you look further up the page on that link you'll see some detailed images of my installation, which should make it quite simple. 1 Quote Link to comment Share on other sites More sharing options...
KLund1 Posted May 7, 2016 Author Share Posted May 7, 2016 Thanks, those pics are helpful. Getting parts... stay tuned... Quote Link to comment Share on other sites More sharing options...
KLund1 Posted May 8, 2016 Author Share Posted May 8, 2016 As for the parts, forget Fried Electronics and eBay. Look at Mouser, Digi-Key, and Jameco. DRam 4164 Mouser, Digi-Key not carried Jameco estimated shipping date 8/1 Any other good sources?? Quote Link to comment Share on other sites More sharing options...
Panther Posted May 8, 2016 Share Posted May 8, 2016 (edited) 41464, not 4164. Jameco item # 41574. I purchased mine from Jameco. They don't specify the brand, so they could change order to order, but the ones I received are NEC. Edited May 8, 2016 by Panther Quote Link to comment Share on other sites More sharing options...
ClausB Posted May 8, 2016 Share Posted May 8, 2016 No, you DO want 4164 or equivalent 64Kx1 DRAMs. The 41464 chips are 64Kx4 which will not fit in a 400 (but will in a 600XL). 1 Quote Link to comment Share on other sites More sharing options...
Panther Posted May 9, 2016 Share Posted May 9, 2016 (edited) Oops! That's what I get for getting up too early in the morning. I had been discussing a 600XL memory upgrade and got confused about what I was replying to. Yes, 4164. Jameco part # 41662...which, yes, they appear to be out of. Edited May 9, 2016 by Panther Quote Link to comment Share on other sites More sharing options...
KLund1 Posted May 9, 2016 Author Share Posted May 9, 2016 Ya I get that, but late at night after a couple tall ones. Suggestions on other sources? There is a set of 8 on ebay for $6.00. http://www.ebay.com/itm/251666089003?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT .74 each ??? Quote Link to comment Share on other sites More sharing options...
JoSch Posted May 9, 2016 Share Posted May 9, 2016 As an aside: Claus' upgrade guide mentions a GTIA upgrade for the 400. I assume that this is just a drop in replacement. But since an article is mentioned, it would seem that there are caveats. First caveat to cross my mind would be: Must the GTIA be the NTSC one? Can somebody elobarate on what to keep in mind, when attempting a CTIA replacement? Quote Link to comment Share on other sites More sharing options...
ClausB Posted May 9, 2016 Share Posted May 9, 2016 That eBay seller is in Poland and shipping will take a while. The site linked below is in Atlanta AFAIK but I have never bought from them. Search this forum for Arcade Chips to see what other buyers' experiences have been. http://www.arcadechips.com/product_info.php?products_id=201 Quote Link to comment Share on other sites More sharing options...
Panther Posted May 10, 2016 Share Posted May 10, 2016 Jameco now shows a ship date of 5/13/16, so it looks like they're getting more in stock this week. Quote Link to comment Share on other sites More sharing options...
JoSch Posted May 10, 2016 Share Posted May 10, 2016 Has anyone tried to use the 64k mod from Claus' upgrade? Quote Link to comment Share on other sites More sharing options...
Panther Posted May 10, 2016 Share Posted May 10, 2016 Has anyone tried to use the 64k mod from Claus' upgrade? I haven't, but the problem is what are you going to use it for? A 16KB ramdisk? It just doesn't seem to serve much use. Quote Link to comment Share on other sites More sharing options...
ClausB Posted May 10, 2016 Share Posted May 10, 2016 I have never tried it either. A 16K RAMdisk might be useful for MEM.SAV and DUP.SYS if you're a DOS 2 user. The 52K contiguous RAM might cause trouble with the OS too. Quote Link to comment Share on other sites More sharing options...
BillC Posted May 11, 2016 Share Posted May 11, 2016 I have never tried it either. A 16K RAMdisk might be useful for MEM.SAV and DUP.SYS if you're a DOS 2 user. The 52K contiguous RAM might cause trouble with the OS too. I doubt it would cause problems with the OS, Mosaic made a 64K bank selectable memory card, up to 3 could be installed in the 800, that used 4-4k banks accessible in the 48-52K range. The extra memory was even usable with BASIC, a "POKE 106,208" set RAMTOP to 52K, and there were other POKEs to select bank. SYNFILE+ was able to use the extra memory provided by both AXLON and MOSAIC boards. Quote Link to comment Share on other sites More sharing options...
ClausB Posted May 12, 2016 Share Posted May 12, 2016 Oops, I forgot that my 64K option uses a 16K bank like AXLON, so 52K is no issue. Quote Link to comment Share on other sites More sharing options...
JoSch Posted May 19, 2016 Share Posted May 19, 2016 (edited) I successfully installed the expansion variant of Claus. Works great. Even SDX boots up. The enhancement for the last 16k is on my list now, but I need to get the IC first. PS: I used two 1kOhm resistors, because I hadn't the 680 Ohm ones. Still works. Edited May 19, 2016 by JoSch 1 Quote Link to comment Share on other sites More sharing options...
Lynxpro Posted May 22, 2016 Share Posted May 22, 2016 Oops, I forgot that my 64K option uses a 16K bank like AXLON, so 52K is no issue. Can't you also upgrade the OS so you don't have to split up the RAM upgrade? Or is due to a preference to keep the OS ROM stock? Quote Link to comment Share on other sites More sharing options...
gamer-stu Posted May 24, 2016 Share Posted May 24, 2016 I have a couple 400's I want to upgrade to 48K. I know there are ways to change a 16K card to 48K. Are there kits out there for sales other than BestE? Those prices have really gone way up. Or are there simple instructions some where in here that easily show how to do the upgrade? Hopefully with some pictures. I have googled and have found multi page detailed guides to do it, but they had terms, parts, and details I did not understand. I have another 400 that I upgraded a few years ago with an Atari 400 48K Expansion Kit. I could use that as a template for the MB jumper wires perhaps. I also need a cart door spring. I can't find any at Home depot or Lowes that work or fit. I just purchased a cart door spring from Bradley at Best. 400 - door spring - CO14104 - $1 Quote Link to comment Share on other sites More sharing options...
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