31336haxx0r Posted October 26, 2012 Share Posted October 26, 2012 Buddies, I'm stuck. I have an 800XE, which is basically a 65XE, I want to upgrade to 256kB or more. Now one could easily install a CO25953 in there, but I don't have access to one. And the price tag is too high for my taste: with shipping to Europe it's going to be a killer! I have seen so many RAM upgrades already and all of them are flawed in one way or other. I am looking for the "perfect" RAM upgrade, sort of: - it mustn't use hard to get chips (like CO25953, other PALs and GALs) - it must work on 800XE and 800XL, as I have both of them here and don't want to build entirely different stuff for them. Twice. - I have access to DRAMs, SIMMs and SRAMs. The upgrade may utilize any of those. I don't have a preference on what kind of RAM it should use. - I'd like to retain BASIC. 130XE banking mode compatibility is nice but not necessary for my purposes Can anyone point me into the right direction? Quote Link to comment Share on other sites More sharing options...
+bob1200xl Posted October 26, 2012 Share Posted October 26, 2012 Does a RAMBO work? It should... It uses bit 2,3,5, and 6. No ANTIC mode. Bob Quote Link to comment Share on other sites More sharing options...
Rybags Posted October 26, 2012 Share Posted October 26, 2012 Without the EMMU or PAL/GAL solution the homebrew alternative is logic chips or an Eprom - all of which add bulk and plenty of scope for instability. Ultimate 1 Meg is top of the line solution but probably not available right now and a bit costly. Lotharek is developing a 1 Meg upgrade that IIRC just plugs into the CPU socket, that has the potential to be the best low-cost pro upgrade. I think there's also a RAM 320XE or similar in progress or already here, plugs into ECI port but downside there is it can limit other expansion capabilities. Homebrew stuff with Simms and the like - you might save a few bucks but end up with a spagetti mess that will probably not be very reliable or nice to look at. Quote Link to comment Share on other sites More sharing options...
31336haxx0r Posted October 26, 2012 Author Share Posted October 26, 2012 I like logic chips and have plenty of them. Quote Link to comment Share on other sites More sharing options...
Fox-1 / mnx Posted October 26, 2012 Share Posted October 26, 2012 http://www.horus.com/~hias/atari/#sram512k 512KB. Requires 1 GAL to be programmed. 1 Quote Link to comment Share on other sites More sharing options...
MEtalGuy66 Posted October 26, 2012 Share Posted October 26, 2012 (edited) Yeah.. Thats your absolute best bet (the link Fox-1 posted above).. It has the c025953 circuitry implemented in the GAL.. so you get true 130xe compatability, 320k rambo/compyshop, and 576k modes... and it's cheap, and relatively few wires to hook up.. You just need a single 512kx8 SRAM piggybacked on top of the OS or BASIC ROM, 1 GAL, and about 12 wires... If you cant program a GAL, there are plenty of people on here who can do it for you cheap.. In fact, since you're in Germany, you probably already know Berndt or Wolfram (the guys who developed it).. They are both ABBUC members.. Edited October 26, 2012 by MEtalGuy66 Quote Link to comment Share on other sites More sharing options...
Marius Posted October 26, 2012 Share Posted October 26, 2012 Fox-1 has the right suggestion indeed. I have done a few of these upgrades, and it is a keeper. Absolutely. Very stable, very compatible, very simple to build, and... cheap! The only thing I did different was that I made it all on a home-made hobbyprint board. I build one in a 65XE, one in a 800XL and one in a 65XE (Like your 800XE). Works great. I'm not sure it can be build in a XEGS. You might lose the Missile Command game then... not tested. Anyone? Quote Link to comment Share on other sites More sharing options...
Mathy Posted October 26, 2012 Share Posted October 26, 2012 Hello guys If 31336haxx0r comes to the ABBUC meeting later today, he'll meet Bernd and me. Probably mega-hz also. Maybe Fox-1. Sincerely Mathy Quote Link to comment Share on other sites More sharing options...
31336haxx0r Posted October 27, 2012 Author Share Posted October 27, 2012 (edited) Sorry, I don't know any ABBUC members. Where is that ABBUC meeting? While that upgrade seems nice, it still uses a GAL. Is there a way to replicate this by using discrete logic chips? Edited October 27, 2012 by 31336haxx0r Quote Link to comment Share on other sites More sharing options...
HiassofT Posted October 27, 2012 Share Posted October 27, 2012 While that upgrade seems nice, it still uses a GAL. Is there a way to replicate this by using discrete logic chips? The idea of this upgrade was to replace the bunch of logic chips with a single GAL, but of course you can reverse this if you really want to :-) You can find the GAL logic in sram13.pds. If you prefer standard logic equations download JED2EQN (a DOS tool) and use it to "disassemble" the sram13.jed file. so long, Hias Quote Link to comment Share on other sites More sharing options...
Mathy Posted October 27, 2012 Share Posted October 27, 2012 Hello 31336haxx0r Aren't you a member? The meetings (JHV) was today. Sincerely Mathy Quote Link to comment Share on other sites More sharing options...
Marius Posted October 27, 2012 Share Posted October 27, 2012 Please take my word, and do NOT use logic chips for Atari 8bit ram extentions. It simply does NOT work reliable. I have done it a lot, and sometimes it seemed to work great... but in the end it was always a disappointment. It is so easy to buy a GAL burner on ebay. Having such a device is always nice. I had to replace a few MMU chips in the past. That is easy too you know. There is a replacment MMU.jedec file available, and you program that in the right GAL and there you go... a replacement MMU for atari XL/XE! Quote Link to comment Share on other sites More sharing options...
31336haxx0r Posted October 28, 2012 Author Share Posted October 28, 2012 (edited) I simply hate the idea of shelling out 50 or 60 bucks for a GAL burner, only to find out it doesn't work aka I'm too dumb to use it/won't work with my PC, etc. I still like logic chips. What GAL burner can you recommend? Where can I get it and new GAL chips? BTW, can programmed PALs and GALs be reprogrammed? Edited October 28, 2012 by 31336haxx0r Quote Link to comment Share on other sites More sharing options...
Mathy Posted October 28, 2012 Share Posted October 28, 2012 Hello 31336haxx0r Why not ask somebody to burn it for you? Mathy Quote Link to comment Share on other sites More sharing options...
HiassofT Posted October 28, 2012 Share Posted October 28, 2012 I simply hate the idea of shelling out 50 or 60 bucks for a GAL burner, only to find out it doesn't work aka I'm too dumb to use it/won't work with my PC, etc. I still like logic chips. What GAL burner can you recommend? Where can I get it and new GAL chips? Forget about the cheap (50-60 bucks) programmers, they are usually utter crap. I once bought one of these, a TOP2004, just to find out it doesn't program GAL 22V10 chips correctly. And there was not support from the manufacturer at all, neither a working software update nor a working contact email address. The working universal (GAL/EPROM/...) programmers usually cost 5-10 times the amount, but you also get support from the manufacturer. Lattice discontinued all GAL chips some time ago, but you can still buy compatiple chips from Atmel (ATF22V10C, for example). I'd recommend you contact Jürgen (tf_hh here on the forum), he's from Germany and I'm sure he can send you a programmed GAL for a few bucks. BTW, can programmed PALs and GALs be reprogrammed? GALs can be reprogrammed. PALs aren't available anymore, they have been superseeded by GALs. so long, Hias Quote Link to comment Share on other sites More sharing options...
Gunstar Posted October 28, 2012 Share Posted October 28, 2012 AtariMax sells an unadvertized Rambo compatible upgrade that has 256K or 512K options (extra piggybacked ram chips and a few extra solder connections). Just e-mail him. It includes everything you need. Quote Link to comment Share on other sites More sharing options...
+skr Posted October 28, 2012 Share Posted October 28, 2012 Sorry, I don't know any ABBUC members. Where is that ABBUC meeting? Hello. It was in Herten (Recklinghausen). For the 27th time. Where are you located? Please just check the ABBUC Forum to find members near you. If you live in the north, you can join the bi-monthly regional meeting in Elmshorn, where you will meet hardware wizards like tfhh, BigBen, HardwareDoc and many others. I live in Wolfsburg and do some small meetings here too. There are active Atari 8 Bit users from ABBUC nearly everywhere in Germany. Quote Link to comment Share on other sites More sharing options...
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