The data register and the control register can be input or output. But the status register can only used as an input.
To answer your question, according to what I researched in google, yah it's possible to use the data register as an input ng control register.
As long as you are careful how you interface your circuit, ok lang yan. Marami namang tutorial diyan about parallel port interfacing.
Depende na rin sa parallel port mo dahil meron mga parallel port na hindi nag support ng dual direction.
By the way, ano language gamit ninyo?
