Here are some photos or the original board http://vintagecomputer.net/teletype/ASR33_4915D/
I have found with DEC computers you don't need the relay to simply load in a tape, such as BASIC into memory. Bill On Sat, Jul 4, 2015 at 12:02 PM, tony duell <[email protected]> wrote: > > > > > Now to see if I can find out how to make a facsimile of the tape reader > control gizmo that DEC > > used to allow the PDP 8 to control the paper tape reader, so I can get > this terminal properly > > interfaced to the 8/e. In the meantime, I'm going to hook it up to > the Altair 8800 for a little > > immediate nostalgia. > > Various companies had their own version of the reader control board, but > they were all much the same in > principle. A relay with contacts in series with the reader control circuit > (the one that operates the trip coil > at the back of the typing unit. The important thing is that it is a relay. > In most cases that reader control > circuit is not isolated from the mains power line. The relay, of course, > provides isolation between the > computer (coil) side and the contacts. > > If you are tempted to use some more electronic solution you must preserve > this isolation ,for example by > using an optoisolator. You do not want to give you and your 8/e a nasty > shock. > > -tony >
