I know its common, but I hate the 8255.
Its to big, to slow, to inefficent and thus to old.

If you want still use many wires for memory mapped IO, why not use 74HC238 and some 74HC573. These are also able to drive 4mA enough for today high efficient LEDs or the 74AC573 can drive up to 48mA which should be sufficient for all LEDs.

But I prefer always using 74HC595 devices to drive 8 or 100 or more LEDs over only 3 lines.

Forget not the current limiting resistors !


Peter