V.C.F. wrote... -------------------------------------- I'm trying to interface a DEC CR11 (a.k.a. Documation M200) card reader to an Apple ][. I need the pinouts of the card reader interface. Does anyone have this information? Is the service manual available online (in some nook I haven't looked into yet)? -------------------------------------- Dang! Where was that link (from a following message) a couple of years ago when I was trying to do something similar??? <G> Using an Altair for a card reader controller to connect to a PC... <snicker> One thing to watch out for that bit me REAL hard when doing this, is that the data lines on the connector are the raw, unlatched outputs from the phototransistors, and the mechanically generated 'column strobe' signal has a significant amount of slop/jiggle/window (pick your favourite) in it and needs some 'processing' in order to insure valid data. I ended up recreating a circuit that I found detailed in the DEC CR11 Interface Board docs. It used a couple of monostables to delay the 'column strobe' signal by an amount, and then stretch the signal for reliable triggering. (or was it the other way 'round? - stretch then delay?) Anyway... without the 'processing' of the strobe signal the data was completely unreliable. To the point of appearing totally random! Hopefully someone has this doc at hand (or it is covered in the reader hardware manual) for reference. Mine is still buried somewhere in the chaos! Good luck! -jim --- jimw(a)agora.rdrop.com The Computer Garage - http://www.rdrop.com/~jimw