REV H DMA / 1772 mods

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REV H DMA / 1772 mods

Post by exxos » Tue Dec 11, 2018 4:46 pm

I started a new schematic , so we on REV H now.

I've added in the 1772 buffers... Though I actually realise we should probably have pullups both sides of the buffer... When the 1772 bus was linked to the DMA, it only needed one pull up array..

I can't remember what we decided to add now, but think we decided to add the STE type buffers onto the DMA port as well ?

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Re: REV H DMA / 1772 mods

Post by exxos » Tue Dec 11, 2018 5:00 pm

I've added in the DMA port buffer...

Also updated the DMA connector pin labels...

2.JPG
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A few other things on the STE were buffered...
Capture.JPG
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I guess it would help if someone with ultrasatan could measure the DMA port signals which are shown to be going via the LS244 buffer to see if they need any buffering or not...

I am also not sure if I should add the 68R resistors in series with the databus or not...
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