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Front Panel LEDs/Switches I/O Mapped

A project log for 3-Chip Z80 Design

Combining a Z80 retro design with a modern PSoC CPU.

land-boards.comland-boards.com 10/14/2019 at 23:390 Comments

Mapped the front panel to I/O addresses 24-27 (dec). The NASCOM basic uses INP to read I/O ports and OUT to write I/O ports.

Writing to address 24 (dec) writes to the bottom LEDs. Writing to address 27 (dec) writes to the top row of LEDs.

Reading address 24 (dec) reads the bottom switches. Reading address 27 (dec) reads the top row of LEDs.

Of course, the other two sets of 8 LEDs and switches are at 25 (dec) and 26 (dec).

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