" what do I need for a manual pulse generator to work with this setup ? "

If your talking about a MPG like this

Attachment 431736

which contains a rotory quadrature encoder
and switches to select
1 of 6 axis
1 of 3 step size
E stop

for this type of simple MPG you need a second parallel printerport or a USB / Ethernet control board emulating a second printer port


John

PS
circuit of MPG
Attachment 431740