2008-09-28

Mini85 - First Circuit Schematics

The first version of the schematics is finished... There are still some optimizations to do, specially regarding the logic gates. The resistors in the directly connected to the 8085 are not really necessary but handy if a later expansion is needed.
This part of the circuit also include the FDC-DMA blocking circuit, the IO decoding and the Memory decoding and the reset circuit.



The second sheet holds the Memory (ROM and RAM), the addressable latch for swapping RAM/ROM and a single Output bit for the serial port (CRT_TXD).



The third sheet holds the floppy disk interface, data separator FDC9216, write clock divider, Drive interface and floppy connector.



The forth sheet (still to come) will hold the switching power supply and the motor on circuit.
It is still difficult to print schematics with gschem, I tried the light output but it is not the best, I'll have to try again with light background and no colors. I will also try to print out a list of connections to do the wire wrapping circuit.

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