Thanks for the link! I didn't know about it. Looks like a pretty straightforward trick, very helpful. Marc
> On May 4, 2016, at 8:32 PM, Bob Rosenbloom <boba...@sbcglobal.net> wrote: > >> On 5/4/2016 5:52 PM, Charles Dickman wrote: >> Has anyone ever worked up a PC parallel port to Facit 4070 paper tape >> punch interface? >> >> I found one on a Swedish website. The punch parallel input looks like >> it is TTL compatible, but I can't find anything in the documentation >> that describes the input voltage specifications. >> >> Chuck > > Check this link out: > > http://www.chiark.greenend.org.uk/~pmaydell/misc/cardpunch/dongle.htm > > It shows how to build a PC to 4070 interface. Basically inverting a few > signals. > > Bob