re pc parallel i i o erickson azure nmt edu alan erickson writes i m trying to bring in bits to a pc and would like to use interrupt driven routines without buying an io board or making a new port where can i bring in these bits lpt seems to have only a few inputs but i ve heard rumours that some lpts have bidirectional lines anybody know fer sure if any bi d lpts which boards have them i ll be running a new dx yes it is possible i m making a stepper controller board with digital inputs and up to digital outputs from the port one main thing that will tell you whether the port is bi directional or not is the bus tranceiver on it look for a chip numbered ls if you don t have this then it s probably a ls which will do you no good for reading in now if you do have the then do the following first find the address of the port decimal either or in pascal you would write port xxx where xxx is the address in either hex or decimal the status lines pins as well as the strobe pin are bi directional lines and are read by base address so for to read from status then read from you can also output to these lines in the same fashion as to the data lines in pascal do port xxx value hope this helps let me know if you need more help inspiration comes to o baden sys bison mb ca those who baden inqmind bison mb ca seek the baden de bari unknown
