re wanted a to d hardware for a pc in article apr doug cae wisc edu kolstad cae wisc edu joel kolstad writes in ncr mpd ftcollinsco ncr com brad wright writes if you know much about pc s ibm comp you might try the joystick port though i haven t tried this myself i ve been told that the port i believe that the a d converters found on a joystick port are really timers that tick off how long it takes an r c circuit the r being your paddle to charge up to something like vcc for games this works pretty well but you certainly wouldn t want to try to take lab measurements off something as non linear as that the best info i have seen so far is the article joystick metrics measuring physical properties through the pc s joystick port by michael covington in the may issue of pc tech journal it talks about how to read all kinds of things voltage current resistance in basic and even includes code for a simple oscilloscope display it s possible to read the joystick port directly if you don t want to use basic the detailed information for this is in the pc technical reference under options and adapters you have to provide some millisecond resolution timing functions but that s a subject which has appeared many times in articles from dr dobb s circuit cellar ink etc look for the public domain ztimer package on wuarchive good luck dev palmer dpalmer mcnc org mcnc room p o box rtp nc fax
