a8maestro Posted August 8, 2007 Share Posted August 8, 2007 I need to finish other things first. The current 4 bit Dram 130XE upgrade has peculiarities I am running out of ideas on. Though they spark old memory bits. Rick. Well, looking at ram specs has shown me a possible cause, and a solution. If that doesn't work, I have 2 other ideas. Rick Quote Link to comment Share on other sites More sharing options...
a8maestro Posted August 28, 2007 Share Posted August 28, 2007 Hi, I've developed a ram upgrade, to put 256K chips in the second bank of 2 sockets..its a plug in daughter board with only three wires to solder. Can't just drop in chips, the pinouts are different. But, I don't have this type of xe to test the prototype on. Rick D. AUG 27, 2007..... The 256K memory upgrade prototype I tested with a borrowed 130XE(Thx Larry W), using 2 drams for the upper bank has passed all of the tests. I am having PCBs made which will arrive on Aug 29. So I'll have pcb, kit, and assembled available. Advert on my site. I am also updating the standard 130XE upgrade, 256K using 8 drams. Rick D. Quote Link to comment Share on other sites More sharing options...
Marius Posted August 28, 2007 Share Posted August 28, 2007 In the past I made a 320XE out of an 65XE with 2x 4bit DRAMS First I used 2 44256 RAMS, but for some reason I had random data failures with these. I still don't know why. Perhaps someone can explain. I remade this upgrade 3 times (all the time with new 44256 rams), but still problems. Then I replaced the 44256's rams with a SIMM and then everything works fine. I don't know what problem that was... Perhaps something with the refresh. I stabalised the Atari with the stabalising mod of Bob Puff... so there were no PH0/PH2 problems on this XE. Perhaps someone has tips? Marius Quote Link to comment Share on other sites More sharing options...
+Larry Posted August 28, 2007 Author Share Posted August 28, 2007 In the past I made a 320XE out of an 65XE with 2x 4bit DRAMSFirst I used 2 44256 RAMS, but for some reason I had random data failures with these. I still don't know why. Perhaps someone can explain. I remade this upgrade 3 times (all the time with new 44256 rams), but still problems. Then I replaced the 44256's rams with a SIMM and then everything works fine. I don't know what problem that was... Perhaps something with the refresh. I stabalised the Atari with the stabalising mod of Bob Puff... so there were no PH0/PH2 problems on this XE. Perhaps someone has tips? Marius Do you have any details of your upgrades (44256 and SIMM)? Wiring diagram or such? -Larry Quote Link to comment Share on other sites More sharing options...
Marius Posted August 28, 2007 Share Posted August 28, 2007 This is the same upgrade as already described in this topic, but when I have some time this week, I'll draw it. It is really a SIMPLE upgrade. But the 130XE bankswitching PAL is needed for this one. I still think that is the best solution. I'll let you know later this week (i hope) Marius Quote Link to comment Share on other sites More sharing options...
a8maestro Posted August 29, 2007 Share Posted August 29, 2007 (edited) In the past I made a 320XE out of an 65XE with 2x 4bit DRAMSFirst I used 2 44256 RAMS, but for some reason I had random data failures with these. I still don't know why. Perhaps someone can explain. I remade this upgrade 3 times (all the time with new 44256 rams), but still problems. Then I replaced the 44256's rams with a SIMM and then everything works fine. I don't know what problem that was... Perhaps something with the refresh. I stabalised the Atari with the stabalising mod of Bob Puff... so there were no PH0/PH2 problems on this XE. Perhaps someone has tips? Marius The 1 bit 64K and 256K, and 4 bit 64K dram all have 256 cycle refresh. The 4 bit 256K dram has 512 cycle refresh, so the refresh mod has to be applied. This is what fixed my upgrade so I can get pcbs made. Rick D. (EDIT: I have posted info/links on my 130XE 256K memory upgrades on Sep 04 new topic.) Edited September 5, 2007 by a8maestro Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted December 3, 2011 Share Posted December 3, 2011 (edited) Necrobump... did the instructions for a 320KB upgrade for the 64x4 boards ever get written up? Edited December 3, 2011 by flashjazzcat Quote Link to comment Share on other sites More sharing options...
fibrewire Posted December 4, 2011 Share Posted December 4, 2011 http://atrey.karlin.mff.cuni.cz/~pavel/atari/130xe320K.html Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted December 4, 2011 Share Posted December 4, 2011 http://atrey.karlin..../130xe320K.html That's the original 8 chip 320k mod, but I'm talking about what MG describes here on page 1 of this thread: you shouldve got 41256s.. Theyd work just as good. and then when you decide you want more ram, you just add 1 memory adress line, 2 lines to the pia portb outputs, a multiplexer IC and a resistor (basically 50 cents worth of parts), and youve got a scott petersen 320k XE. Quote Link to comment Share on other sites More sharing options...
fibrewire Posted December 4, 2011 Share Posted December 4, 2011 Just ask Mathy and Hias http://mobile.google...51b76e67516af67 Quote Link to comment Share on other sites More sharing options...
flashjazzcat Posted December 4, 2011 Share Posted December 4, 2011 Yikes... that link sent Firefox into a tormented perpetual loop of page refreshing! Quote Link to comment Share on other sites More sharing options...
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