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  • Author Author: dubbie
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An 8085 Microcomputer Design (from way back)

dubbie

I was just doing some tidying up and came across a hand drawn schematic for an 8085 microcomputer that I must have design 30 or 40 years ago. I cannot say exactly when as I do not remember doing it! If it wasn't in my hand writing I would have said it wasn't me.

 

image

 

I don't really remember making this design although it is possible I made this when I first encountered wire-wrap as a method of making prototype boards. I have another diagram showing the chip placements but nothing that shows any PCB layout. I would have remember this PCB layout.

 

How times change, or maybe, how electronics changes.

 

Dubbie

 

PS You might need to expand the picture view if you want to see any of the details.

  • in reply to ccandrews

    I used one of the MCS-85s on my degree programme, doing machine code programming (machine code!). I wanted to use one for my final year project of a text output system for physically disabled people, just with two joystick type switches for input (or was it one - it was a long time ago) to select the letters displayed as an array, but the department only had two and they both went to the overseas students who joined in the final year. Instead I ended up implementing the whole system in TTL logic (about 8 boards worth), including making my own text monitor from a portable TV, video sync driver, character font design and everything.

     

    Dubbie

  • in reply to dougw

    I agree, I really enjoyed using the 8085, a pity I eventually had to move on to the 8088, mostly because it was the basis of the IBM PC. I did also design an 8088 based micro computer but I cannot fin dthe schematic for that, which was done on a CAD system. Not quite the same 'home-made' feel about it.

     

    Dubbie

  • in reply to dougw

    I Still remember when I first saw the 8085-8755-8156 single board computer system with its PCB layout in the intel MCS-85 user manual.  It blew my mind and is still my favorite platform decades later.

  • Cool.

    The first complete microcomputer PCB I ever designed was an 8085. They really did a good job with all the peripheral chip pinouts so they could all be easily bussed together.

  • If you want to return to your youth, Here is another 8085 single board computer you can buildthat is not all that different than your original design (except it uses SID/SOD rather than USART)

     

    sbc-85.com