Hi Thomas, Drive selection is achieved using a D Type flip flop (U16A) where the data input is data line DO0, this data line is clocked into the flip flop through the combined SEL_SECOND* and WR* signals thorough NOR gate U15A. you need to be looking in this area with a logic probe/ logic analyser to see if the pulses are generated when you address the port. One other possibilty which springs to mind is , Have you jumpered K1 (reset jumper) or is it floating. U16A uses the reset line to initialise the flip flop output Q (pin 5) to low and thus illuminating D18 (CF-A SELECT). Please make sure you are using the schematic dated 23/3/2014 regards David Fry On Tuesday, March 18, 2014 10:27:41 PM UTC, Edward Snider wrote:
> Hi everybody, > > I'd like to do a board distribution project of Dual CF-Card/Hard Disk IDE > S-100 Boards > <http://s100computers.com/My%20System%20Pages/IDE%20Board/My%20IDE%20Card.htm> > . > > Is anyone interested in getting one or more of these? > > Just post here and I'll get a list started. > > Thanks, > > Ed > > -- You received this message because you are subscribed to the Google Groups "N8VEM-S100" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
