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7800XMs - Just checking in...


Curt Vendel

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Curious (and please pardon any ignorance on my part), I am under the impression that the High Score Cart uses $1000-$17FF for SRAM and $3000-$3FFF as ROM space.

The XM is doing the same thing, right (?)

I'm asking because I'm trying to understand where/why there would be conflict or an issue regarding $4000-$7FFF and high score saving :?

 

 

Or is there a possible conflict with XBOARD Control? But I thought that was $0470-$047F.

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Here's the issue. Bit3 of $0470 enables the XM HSC. But it also enables XBOARD RAM at $4000. My game has ROM at $4000. So when I enable the XM HSC, it could also enable XBOARD RAM that overlaps my game. If I didn't have ROM at $4000, this would be a non-issue, but since I do, people have to make sure they don't use this cart with an XM installed in a machine with an XBOARD. Probably not a likely occurance, but theoretically, it's possible.

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The same potential issue exists if someone want's to use the XM's RAM at $4000 plus it's HSC feature. Even the POKEY's will conflict. It might be best to just put a warning in the XM documentation that it should not be used with machines containing an XBOARD. Or the XM BIOS needs to test for the XBOARD at boot time and provide some way to communicate it's presence so the application can handle it correctly.

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Perry, I have to agree with everyone, this looks like a really fine piece of software. No matter how many times I see it, it just doesn't get old.

 

And Curt, congratulations on your continued efforts and perseverance, too. Thanks for breathing new life into our little old baby.

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Got the XM test unit today... Although it won't seem to work with one of my 7800s (the white one - my main unit) :( Powers on to a blank screen no matter what I do.

I'm going to try it on my backup unit.

That is a real disappointment Bob..........Hopefully it works on your backup.

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Berzerk VE worked fine with and without the XM, not sure what is going on with Bob's 7800 and the XM, but we'll have to see. The XM has been tested on two different NTSC systems (84' and an 87') and 2 PAL UK 7800's and there weren't issues, I'm leaning towards something jarring loose in shipping on the XM Bob got, remember its a dev unit with lots of WIP wires and such, plus the CPLD is not fully secured with a lock down band so I'm wondering if it may have popped (having Atari ST Deja Vue with the ST chips popped out during shipping...)

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Thank Mitch - I think I'll take you up on that offer, let me square away with a few old things I owe you and Jose...

 

XM arrived about 2-3 hours ago, I plugged it in, dead as a doornail, I opened it up, everything was seated fine, I plugged in Bob's Pac Man 320 board that I have (Romans PC Board design) and no Pokey, no nothing, I checked the signal lines, it wasn't getting any CS signals, nothing, so I put in a new CPLD, still nothing. Then I poked around to a few jumper lines and sure enough I found the culprit - there is a clock delay circuit on a small daughterboard, the +5v line had somehow come off of the test point where it was connected, so it had no power and wasn't sending a clock signal to the CPLD, so it was just sitting there brain dead and not controlling any of the devices in the XM. Soldered it back really well, powered up the XM and there it was, everything back up and running.

 

Hope everyone enjoys playing the XM demo's at the Portland show, Albert showed me the booth lay out for Atari Age, its like a show within the show... it certainly won't disappoint.

 

Someone asked about ordering - sorry, no further orders until the XM's ship to all of the people who pre-ordered and supported this project early on, their orders were like an Atari Age version of kickstarter, it funded the cost of the steeling tooling for the plastics and the production of the plastic cases, tooling and production of the aluminum name plates, cost of the boxes and manuals so they get taken care of first and foremost before any new orders will be taken, so hang in there, still have a lot to do and the programmers came back with some good feedback on some things, so those ideas and changes will be implemented, now it looks like some compatibility testing with the several versions of the 7800's will have to also be done.

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@FujiSkunk -

 

I honestly don't know what you are referring too and sorry, I don't know your real name associated with your forum name. Best way to find out something with me is to directly email me, and give specifics like an order ID#, name and such so if something has been missed, I will know what it is and can address it. Making a forum post and having no information really doesn't allow me to help you. My direct email is on my website (link in my signature) or just email me at curt@atarimuseum.com

 

Thanks.

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