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Conversion of the schematics of the Atari STE motherboard into Kicad

Sporny Kun

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The title says all, I have converted the existing schematics into Kicad. This is the 1.0.0 release, and hopefully there will be no erratum.

https://github.com/sporniket/kicad-conv ... /tag/1.0.0

The release provides a PDF with the schematics, a PDF with the silkscreen of the motherboard reconstruction, and a ready to use Kicad project (libraries included).

For the schematics, I have decided that :

  • Symbols for the ICs will show the physical layout of the pins, as it makes it easier to spot the pin on the real IC (for me at least). And because thanks to that, the GSTMCU still fits on an A4 sized sheets. On one occasion I deviated from this choice (for the dma sound amplification and filtering) as it obfuscated too much the circuit.
  • Each original sheet is splitted so that each sub-part is printable on a A4 sized sheet.
  • A Table of content


I also have mentionned some fixes that would be usefull/mandatory.

  • DMA pull-up on databus
  • WD1772 pull-ups
  • LMC audio mix fix
  • RGB Video ghosting fix
  • C415 that should be reversed


The projects contains an approximative reconstruction of the motherboard's PCB. It will be good enough to locate a given component and to know how a signal is distributed accross the board. And it allow to make nice 3D renderings.







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  • 1 year later...

It may be a little bit tight, but one may save some space by not supporting the external blitter and the modulator/composite encoder. On the other hand, one could reuse some ideas from Exxos's H5 like a modern RS-232 IC that does not require dedicated voltages converters, and using a single 72-pins SIMM.

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  • 1 year later...


13 hours ago, Mauro Rodriguez said:

where is the original 2 joystick port in this schematic

i have an 520st

The STe, like the STF, has moved the joystick ports away from the motherboard, and put them on the keyboard assembly.


The 520ST (first version, short case, no integrated floppy, no integrated power supply) is then quite different. I have an ongoing project for this model, the PCB is far from done, but the schematic is usable though https://github.com/sporniket/kicad-conversions--atari-260-520-st-motherboard--c070231

A pre-release of the PDF is available here : https://github.com/sporniket/kicad-conversions--atari-260-520-st-motherboard--c070231/releases


Hope this helps.

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