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Atari 1090XL Schematics?

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Well I've managed to put together a prelim schematic for the 1090XL Prototype board as far as the expansion part is concerned. It does not include the power supply part. I leave that to someone else :twisted: (hint....hint....)


I didn't do this alone. James (sup8pdct) was gracious enough to verify my crude attempt at a beginning schematic and correct my errors. :thumbsup:


To date this appears to be the only known schematic in the wild. Curt supposedly has the full schematic as well as additional info, but he has not responded to either an IM or a email to the address on his website. So take that for what it's worth. It may mean nothing. :)


Prelim 1090XL Schematic.pdf


My idea is this:


I would like to recreate the purpose of the 1090XL, not necessarily the physical box, with a modern well filtered and mannered power supply. . With the advent of SMD technology and MCU's of the modern era, there should be no need for the big hulking box the actual 1090XL was. I know too much modern here. :D


I propose a open framework box that will be compatible with the Atari 600XL/800XL with PBI's and 130XE with ECI through an adapter. This framework will function as a standard interface to the computer's parallel port. Much like the original design of the 1090XL this framework will provide power and signals to allow at least five and possibly the full eight individual pbi devices allowed in the original Atari OS design specs.


Of the known PBI devices so far, it seems most can be easily converted to the framework standard interface. This will in some cases simplify their design and parts count and eliminate the problem of housing the device for the developer. For new designs as well.


Right now I know this is long on idea, but short on facts. I wanted to gauge the interest. And get input on what signals will need to be present on the individual PBI slots for the greatest range of expansion cards. Keep in mind this is not a hack job on the inside of the computer. At most we would be picking signals off the pbi/eci bus for manipulation. ie on the 800XL running an adapter to pick off the cartridge signals.


Now you say what about the Black Box.....? .... what about the MIO? ..... what about XYZ? These are all fine interfaces in and of themselves, but they are not open. And are mired in legacy restrictions of the original design and bios of their time. Expansion is problematic as well. I don't believe the Black Box is being made anymore, and while MetalGuy66 is still trying to keep the MIO alive again it is a closed system with a steep price tag for an unboxed/unpopulated version. Not to gain say MetalGuy66, he has put a lot into the production of that system and should be able to recoup his costs. ;-)


Let me know what you think.




This sounds very cool. Agree that cards like USB or Ethernet, or drive interfaces could be useful.

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Pie in the sky wish that isn't original to me: It would be good if the basic box had something like a 9536xl between the Atari and the expansion cards. I think they are going for <$2 a throw right now and would add a lot of functionality for little cost. Tie most of the address bus lines to the 9536xl and you pretty much have all the decoding you could want to slice up the hardware $D000-$D7FF. If you wanted to do something like the 800xl to four joystick hack, it could all be done through the CPLD with the daughter card only holing the nine pin J/S connectors. Similarly you could do a memory expansion where it could be reconfigured in software/JTAG to look like anything from a Mosaic to Rambo. Lots of the heavy lifting has already been done by FOFT and there are code examples for everything for everything from i2c and spi interfaces.

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