TheRogue Posted April 7, 2009 Share Posted April 7, 2009 I have a question, would it be possible to mod an XEGS to support the ECI bus? I would like to get an MIO, but my main A8 is an XEGS. Does anyone know if anyone has ever added PBI or ECI support to an XEGS? As an extension to this question, if it is possible, and I were to produce a run of boards that added PBI or ECI to the XEGS, would anyone buy it? Any opinions are welcome. Quote Link to comment Share on other sites More sharing options...
+Guitarman Posted April 7, 2009 Share Posted April 7, 2009 (edited) It would probably be infinitely cheaper to just get an XL/XE with the port on it. There is a slight chance that the PBI board that Metalguy did for the 1200XL would work on the XEGS since it connects to the cartridge port but I'm not sure if the XEGS has the PBI code in its ROM. Plus, the board would stick straight out of the top. Edited April 7, 2009 by Guitarman Quote Link to comment Share on other sites More sharing options...
TheRogue Posted April 8, 2009 Author Share Posted April 8, 2009 It would probably be infinitely cheaper to just get an XL/XE with the port on it. There is a slight chance that the PBI board that Metalguy did for the 1200XL would work on the XEGS since it connects to the cartridge port but I'm not sure if the XEGS has the PBI code in its ROM. Plus, the board would stick straight out of the top. I know for a fact that the XEGS has the PBI code in ROM. I'm positive on that fact. Where can I get information/schematic on this 1200XL PBI board? Are they available for purchase, or is it just a project? I would like to get it working on the XEGS. Quote Link to comment Share on other sites More sharing options...
+bf2k+ Posted April 8, 2009 Share Posted April 8, 2009 It would probably be infinitely cheaper to just get an XL/XE with the port on it. There is a slight chance that the PBI board that Metalguy did for the 1200XL would work on the XEGS since it connects to the cartridge port but I'm not sure if the XEGS has the PBI code in its ROM. Plus, the board would stick straight out of the top. I know for a fact that the XEGS has the PBI code in ROM. I'm positive on that fact. Where can I get information/schematic on this 1200XL PBI board? Are they available for purchase, or is it just a project? I would like to get it working on the XEGS. Send a PM to MetalGuy66 Quote Link to comment Share on other sites More sharing options...
Almost Rice Posted April 8, 2009 Share Posted April 8, 2009 This is the last I heard of Metalguy's 1200xl PBI. I do not know if that is updated since that post. Quote Link to comment Share on other sites More sharing options...
Rybags Posted April 8, 2009 Share Posted April 8, 2009 Atari are famous for leaving redundant bits in the OS. Would be interesting to do a comparo between what's different in e.g. the 800XL OS and the XEGS, I imagine it's probably a dozen bytes. They even have the Function Key logic retained through the XL and XEs. In theory, if you put function keys on a 130XE and didn't touch the OS, you'd have an instant means of crashing the machine, or at least causing some havoc. Quote Link to comment Share on other sites More sharing options...
sup8pdct Posted April 8, 2009 Share Posted April 8, 2009 I personally think it would be neater externally to have a PBI like the XL line. However, I think you will need to change the MMU over to a XL/XE one. The GS has an extra line used on PIA for the game which happens to take the MPD line from the PBI, So tracks need to be cut etc James I have a question, would it be possible to mod an XEGS to support the ECI bus? I would like to get an MIO, but my main A8 is an XEGS. Does anyone know if anyone has ever added PBI or ECI support to an XEGS? As an extension to this question, if it is possible, and I were to produce a run of boards that added PBI or ECI to the XEGS, would anyone buy it? Any opinions are welcome. Quote Link to comment Share on other sites More sharing options...
Kr0tki Posted April 8, 2009 Share Posted April 8, 2009 (edited) Atari are famous for leaving redundant bits in the OS. Would be interesting to do a comparo between what's different in e.g. the 800XL OS and the XEGS, I imagine it's probably a dozen bytes. Indeed, they didn't change too much. Between rev.02 and rev.03 they modified the SELF TEST to also test extended memory, and changed few bytes in SIO (it is discussed in detail in this thread). Rev.04 only contains changes to support XEGS' booting with/without keyboard and run Missle Command. They even have the Function Key logic retained through the XL and XEs. In theory, if you put function keys on a 130XE and didn't touch the OS, you'd have an instant means of crashing the machine, or at least causing some havoc. You are contradicting yourself. The fact that they left the F-keys logic in OS specifically means that if you put function keys on a XL/XE system, they would still work as expected. I've even read an article back in the day, about adding F-keys to an XE machine. Edited April 8, 2009 by Kr0tki Quote Link to comment Share on other sites More sharing options...
HiassofT Posted April 8, 2009 Share Posted April 8, 2009 They even have the Function Key logic retained through the XL and XEs. In theory, if you put function keys on a 130XE and didn't touch the OS, you'd have an instant means of crashing the machine, or at least causing some havoc. You are contradicting yourself. The fact that they left the F-keys logic in OS specifically means that if you put function keys on a XL/XE system, they would still work as expected. I've even read an article back in the day, about adding F-keys to an XE machine. Both of you are right. The function keys work correctly, but have a look at the OS code, especially what happens if you press CTRL-F1 or CTRL-F4: The old 1200XL code for toggling the LEDs via PORTB is still in there (at least it was in my 800XL), which now conflicts with RAM extensions.... In Basic, just do a "10 ?PEEK(54017):GOTO 10" and see what happens if you press the keys :-) so long, Hias Quote Link to comment Share on other sites More sharing options...
Kr0tki Posted April 8, 2009 Share Posted April 8, 2009 (edited) You're right, sorry; I forgot about the PORTB incompatibility. Now I start to suspect that the reason they removed the F-keys from 600/800XL, was that they didn't know how to remove the LED code from the OS Edited April 8, 2009 by Kr0tki Quote Link to comment Share on other sites More sharing options...
drac030 Posted April 8, 2009 Share Posted April 8, 2009 I have a question, would it be possible to mod an XEGS to support the ECI bus? You have to replace the MMU, the original XEGS MMU does not use the MPD signal. Quote Link to comment Share on other sites More sharing options...
TheRogue Posted April 8, 2009 Author Share Posted April 8, 2009 I am adding a 130XE MMU to my XEGS to control extended memory in a 1 MB SIMM expansion I'm perfecting right now. That solves that problem. Quote Link to comment Share on other sites More sharing options...
MEtalGuy66 Posted April 8, 2009 Share Posted April 8, 2009 (edited) 1) The MMU doesnt control extended memory.. 2) All that crap has already been done before.. 3) Noone is gonna buy an expansion that they have to hack the hell out of their case to use (well, maybe a few crazy people, but not enough to make a run of boards cost effective). If what you want is a "solder in" solution (And I do mean quite a bit of soldering) to hook a PBI device up to your XEGS, I can send you easy instructions for that.. And yeah.. It will involve shitcanning the "32k MMU" and replacing it with the MMU used in the 600xl/800xl/65xe/130xe.... You will then use a standard 16k ROM just like those machines do. This has to do with the various rom select signals.. not the extended ram. As far as having either an XE style "ECI socket" or XL Style "PBI card edge", I wouldnt do either on the XEGS... Just hang a standard 50-pin "SCSI-style" ribbon cable out the back. You only have to mill a very minimal "slot" in between where the two case halves split, in order to allow the flat ribbon to hang out, and both the MIO and BlackBox have the 50-pin header on-board for this to plug into... Given the design of the XEGS, this makes more sense than any of that other crap does, and would really produce the best result cosmetically, as well.. Edited April 8, 2009 by MEtalGuy66 Quote Link to comment Share on other sites More sharing options...
TheRogue Posted April 9, 2009 Author Share Posted April 9, 2009 I'd appreciate those directions. As for the chip that I was using with my 1 Meg SIMM expansion, it is the CO25953 gate array, not the MMU, I must of had a brain fart when I wrote that, and now I feel retarded. Anyway, those instructions would be appreciated. Quote Link to comment Share on other sites More sharing options...
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