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kenames99

1090XL remake

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4 hours ago, _The Doctor__ said:

not sure how a voltage doubler would work out at the lower voltages.... I thought he said his cards etc would be 1090 compatible, if it does what the 1090 does and more the it's the 1090e for enhanced maybe....

it would be simple to detect if 12 or -12 were there and act accordingly.

 

Ken

 

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(Mostly) working 320k SRAM card for the 1090...

 

I say "Mostly" because I haven't figured out why SpartaDOS X isn't working with it yet.  RAM testing programs show the memory works, M.U.L.E. works, and DOS 2.5 works with a functional RAMDISK.  But SpartaDOS X doesn't boot.  It's odd.

 

I thought I had it all figured out and this card would be good to go.  When I first installed the card in the 1090 board, I "only" had 64k.  A couple days ago I took a good look at the schematics and realized that one more "undocumented requirement" existed.  Since the 1090 uses transceiver chips, the data bus needs to be active if the memory is called or if the CPU is issuing a write.  Otherwise, the banks cannot be set.  So, I added a formerly unused OR gate into the circuit and now the full 320k is available.

 

I am still trying to figure out the SpartaDOS X issue.  The next version of the card may have a larger heat sink for the voltage regulator, or, maybe I'll just put a small stick-on heat sink on top of the voltage regulator and see if that helps.

 

1259989603_SRAMCard.thumb.JPG.24fd35bf5b78eab39a85832c77c83492.JPG

 

1864866836_600xlwith1090.thumb.JPG.5c3265c8917310c1d9733f48247fbf5d.JPG

 

2144682817_SimpleCheckerMainScreen.thumb.JPG.7ec658cdc81f51225fce4d597e8a9d51.JPG

 

903537736_MemoryBanks.thumb.JPG.90d52fa248d2199a6dc513a4dcfd5284.JPG

 

821738523_ExtendedRAMTest.thumb.JPG.0222f628413d33c8aba05ca5c031630b.JPG

 

 

 

 

1090 w SRAM Card 2.JPG

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Posted (edited)

hi,

  I know the programming inside the Side2 cart gets in the way of the programming in the 1090XL, and suspect the same may be true of the hardware part also but have not tested that. The Side carts with the U1M replace the pbi capabilities at least for storage. maybe FlashJazzCat could shine some light on this as far as the Side carts go. until then maybe try an original type SDX cart?

 

Ken

 

Edited by kenames99
wrong info

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3 hours ago, kenames99 said:

hi,

  I know the programming inside the Side2 cart gets in the way of the programming in the 1090XL, and suspect the same may be true of the hardware part also but have not tested that. The Side carts with the U1M replace the pbi capabilities at least for storage. maybe FlashJazzCat could shine some light on this as far as the Side carts go. until then maybe try an original type SDX cart?

 

Ken

 

I did a little troubleshooting and haven't found any clues yet.  Since I don't have a U1M there isn't any conflict in $D3xx.  A search through the Altirra Hardware Reference Manual didn't result in my finding anything related to a Side3 cartridge that would conflict with a 1090 card.  My 320k PBI card works just fine plugged into the PBI port and is literally what I modified to work in the 1090.  I made a custom config.sys file, on a floppy, with only Sparta, SIO, and AtariDOS drivers loaded.  The 1090 version of the 320k card still fails with SpartaDOS X and the limited config.sys file.  The big difference between the 320k PBI card and the 1090 320k PBI card is that the 1090 320k PBI card has to enable and disable the data bus tranceiver at the right time.  The 1090 also buffers other signals.  But if there was a problem with any of the changes for the 1090 the problem should be a lot more obvious.  

 

I don't have an original SDX cart to try but it's a good idea as that would allow me to see if it's the SIDE3 cartridge or not.  I have been thinking about making a 1090 card that would function as a SIC! cartridge so SpartaDOS X could be loaded on it, though.  I think such a card would have to have a few ROM instructions to disable the internal BASIC cartridge.  Such a card would also have to have the ability to override any other 1090 cards.  (i.e. a memory card)  I'll need to think it through some more.  

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hi everybody,

  I do not know if you would call this history being made but, I have reproduced a working, original Atari designed 80 column video card for the 1090XL expansion box. So after nearly 40 years (35 maybe?) we have true parallel bus 80 column video! I am pleased to finally have it working. Here are some photos of it. It is fully atari design and firmware. having said that, I did notice a peculiarity with it. I had the 40 column display hooked up also, even tho it is supposed to be nonfunctional, after the normal timeout, the 40 column monitor started to do the attract mode (color/luma changes). I will fix that in the ROM code and make that available if anyone would like that done.

 

  I will be putting the schematic and board files on my github as soon as I get it updated properly. thank you all for your patience.

 

Ken

 

20220731_001351746.jpg

20220731_001358674.jpg

20220731_001642600.jpg

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my 1090xl was the very first of the board, many updates since then. the red wire is actually the +5v reference to the card slots. it is unused but put there for reference just in case.

 

Ken

 

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