jacobus Posted December 14, 2008 Share Posted December 14, 2008 I just took apart one of my 800XL's in order to try to fix a bad keyboard and found the pictured mods. I have been able to ID Omnimon XL, but I'm unsure about the rest of the mods, specifically: * The breadboard with three chips (appears to be plugged into an underlying socket) * The EPROM just north of the Omnimon chip * The connector that goes to one pin of the video port Any help with be greatly appreciated! jim Quote Link to comment Share on other sites More sharing options...
Bryan Posted December 14, 2008 Share Posted December 14, 2008 The breadboard looks like a homebrew Rambo upgrade. Quote Link to comment Share on other sites More sharing options...
mimo Posted December 14, 2008 Share Posted December 14, 2008 breadboard looks like Claus B +256k RAM upgrade Quote Link to comment Share on other sites More sharing options...
Urchlay Posted December 14, 2008 Share Posted December 14, 2008 * The connector that goes to one pin of the video port ...probably that's the chroma signal. Most 800XLs are missing the chroma from the monitor jack, but it's easy to do a "one-wire mod" to restore the missing signal. Quote Link to comment Share on other sites More sharing options...
+David_P Posted December 14, 2008 Share Posted December 14, 2008 THe socket above the OS is for BASIC; probably upgraded to BASIC C. Quote Link to comment Share on other sites More sharing options...
MEtalGuy66 Posted December 14, 2008 Share Posted December 14, 2008 (edited) 1.)Claus bucholz 256k (192k extended) ram upgrade. Boot spartados and run RD.COM and it will make a 192k ramdisk.. 2.)The chroma mod lets you use the chroma/luma inputs on some monitors (eg. commodore 1701/1702/1084, etc.) for a sharper/nicer display, instead of the standard composite input.. You have to have the right cable for this, obviously.... Also, these are the signals that S-VIDEO uses, so with the right cable, you can use it with displays that have an S-video input. Edited December 14, 2008 by MEtalGuy66 Quote Link to comment Share on other sites More sharing options...
Roydea6 Posted December 15, 2008 Share Posted December 15, 2008 It also looks like a two way switch above the cartridge slot to switch between Omnimon OS and Atari OS. Quote Link to comment Share on other sites More sharing options...
jacobus Posted December 15, 2008 Author Share Posted December 15, 2008 Thanks very much to everyone who responded! I'll have to wait to test the RAM upgrade, the keyboard turns out to be well and truly #ucked. (as you may be able to see in the top right area of the full MB picture, the keyboard connector is missing the 4th pin) I'll have to try grafting a new lead on. The switch does work, but due the to the keyboard issues I can't try the Reset+Select options, or anything else. Monitor Port - I have a 1702, should be fun to play with! thanks again! jim Quote Link to comment Share on other sites More sharing options...
+Larry Posted December 16, 2008 Share Posted December 16, 2008 THe socket above the OS is for BASIC; probably upgraded to BASIC C. Is/was there a 24 pin eprom with 8K? (BASIC?) I didn't think there were any "64" series with less than 28 pins. (?) -Larry Quote Link to comment Share on other sites More sharing options...
MEtalGuy66 Posted December 16, 2008 Share Posted December 16, 2008 THe socket above the OS is for BASIC; probably upgraded to BASIC C. Is/was there a 24 pin eprom with 8K? (BASIC?) I didn't think there were any "64" series with less than 28 pins. (?) -Larry I have never been able to find any.. There may have been at one time, but they are obsolete/impossible to find nowadayze.. kind alike the C=64 OS ROM.. Quote Link to comment Share on other sites More sharing options...
Roydea6 Posted December 16, 2008 Share Posted December 16, 2008 Have a look here: http://www.atariage.com/forums/index.php?s...p;#entry1633607 Been there done that. Quote Link to comment Share on other sites More sharing options...
+Larry Posted December 16, 2008 Share Posted December 16, 2008 Have a look here: http://www.atariage.com/forums/index.php?s...p;#entry1633607 Been there done that. Hi Roy- Thanks for the info/link -- I still manage to learn something new every day! -Larry Quote Link to comment Share on other sites More sharing options...
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